Tcl Source Code

1 January 1970, 00:00 UTC.  Note that the count of seconds does not
include any leap seconds; seconds are counted as if each UTC day has
exactly 86400 seconds.  Tcl responds to leap seconds by speeding or
slowing its clock by a tiny fraction for some minutes until it is
back in sync with UTC; its data model does not represent minutes that
have 59 or 61 seconds.
.TP
\fI\-now\fR
Instead of \fItimeVal\fR a non-integer option \fI\-now\fR can be used as
replacement for today, which is simply interpolated to the runt-time as value
of \fBclock seconds\fR. For example:
.sp
\fBclock format -now -f %a; # current day of the week\fR
.sp
\fBclock add -now 1 month; # next month\fR
.TP
\fIunit\fR
One of the words, \fBseconds\fR, \fBminutes\fR, \fBhours\fR,
\fBdays\fR, \fBweekdays\fR, \fBweeks\fR, \fBmonths\fR, or \fByears\fR.
Used in conjunction with \fIcount\fR to identify an interval of time,
for example, \fI3 seconds\fR or \fI1 year\fR.
.SS "OPTIONS"
.TP

.PP
The date is determined according to the fields that are present in the
preprocessed format string.  In order of preference:
.IP [1]
If the string contains a \fB%s\fR format group, representing
seconds from the epoch, that group is used to determine the date.
.IP [2]
If the string contains a \fB%J\fR, \fB%EJ\fR or \fB%Ej\fR format groups,
representing the Calendar or Astronomical Julian Day Number, that groups
are used to determine the date.
Note, that in case of \fB%EJ\fR or \fB%Ej\fR format groups, representing
the Julian Date with time fraction, this groups may be used to determine
the date and time.
.IP [3]
If the string contains a complete set of format groups specifying
century, year, month, and day of month; century, year, and day of year;
or ISO8601 fiscal year, week of year, and day of week; those groups are
combined and used to determine the date.  If more than one complete
set is present, the one at the rightmost position in the string is
used.

string of the same meaning in the locale, to indicate whether \fB%Y\fR refers
to years before or after Year 1 of the Common Era.  On input, accepts
the string \fBB.C.E.\fR, \fBB.C.\fR, \fBC.E.\fR, \fBA.D.\fR, or the
abbreviation appropriate to the current locale, and uses it to fix
whether \fB%Y\fR refers to years before or after Year 1 of the
Common Era.
.TP
\fB%Ej\fR
On output, produces a string of digits giving the Astronomical Julian Date or
Astronomical Julian Day Number (JDN/JD). In opposite to calendar julian day
\fB%J\fR, it starts the day at noon.
On input, accepts a string of digits (or floating point with the time fraction)
and interprets it as an Astronomical Julian Day Number (JDN/JD).
The Astronomical Julian Date is a count of the number of calendar days
that have elapsed since 1 January, 4713 BCE of the proleptic
Julian calendar, which contains also the time fraction (after floating point).
The epoch time of 1 January 1970 corresponds to Astronomical JDN 2440587.5.
This value corresponds the julian day used in sqlite-database, and is the same
as result of \fBselect julianday(:seconds, 'unixepoch')\fR.
.TP
\fB%EJ\fR
On output, produces a string of digits giving the Calendar Julian Date.
In opposite to julian day \fB%J\fR format group, it produces float number.
In opposite to astronomical julian day \fB%Ej\fR group, it starts at midnight.
On input, accepts a string of digits (or floating point with the time fraction)
and interprets it as a Calendar Julian Day Number.
The Calendar Julian Date is a count of the number of calendar days
that have elapsed since 1 January, 4713 BCE of the proleptic
Julian calendar, which contains also the time fraction (after floating point).
The epoch time of 1 January 1970 corresponds to Astronomical JDN 2440588.
.TP
\fB%Es\fR
This affects similar to \fB%s\fR, but in opposition to \fB%s\fR it parses
or formats local seconds (not the posix seconds).
Because \fB%s\fR has the same precedence as \fB%s\fR (uniquely determines
a point in time), it overrides all other input formats.
.TP
\fB%Ex\fR
On output, produces a locale-dependent representation of the date
in the locale's alternative calendar.  On input, matches
whatever \fB%Ex\fR produces.  The locale's alternative calendar need not
be the Gregorian calendar.
.TP
\fB%EX\fR

(12-11) on a 12-hour clock.  On input, accepts such a number.
.TP
\fB%j\fR
On output, produces a three-digit number giving the day of the year
(001-366).  On input, accepts such a number.
.TP
\fB%J\fR
On output, produces a string of digits giving the calendar Julian Day Number.
On input, accepts a string of digits and interprets it as a Julian Day Number.
The Julian Day Number is a count of the number of calendar days
that have elapsed since 1 January, 4713 BCE of the proleptic
Julian calendar.  The epoch time of 1 January 1970 corresponds
to Julian Day Number 2440588.
.TP
\fB%k\fR

that \fB%Y\fR does not yield a year appropriate for use with the ISO8601
week number \fB%V\fR; programs should use \fB%G\fR for that purpose.
.TP
\fB%z\fR
On output, produces the current time zone, expressed in hours and
minutes east (+hhmm) or west (\-hhmm) of Greenwich. On input, accepts a
time zone specifier (see \fBTIME ZONES\fR below) that will be used to
determine the time zone (this token is optionally applicable on input,
so the value is not mandatory and can be missing in input).
.TP
\fB%Z\fR
On output, produces the current time zone's name, possibly
translated to the given locale. On input, accepts a time zone
specifier (see \fBTIME ZONES\fR below) that will be used to determine the
time zone (token is also like \fB%z\fR optionally applicable on input).
This option should, in general, be used on input only when
parsing RFC822 dates. Other uses are fraught with ambiguity; for
instance, the string \fBBST\fR may represent British Summer Time or
Brazilian Standard Time. It is recommended that date/time strings for
use by computers use numeric time zones instead.
.TP
\fB%%\fR
On output, produces a literal

Using that time as the base, day-of-week specifications are added.
Next, relative specifications are used.  If a date or day is
specified, and no absolute or relative time is given, midnight is
used.  Finally, a correction is applied so that the correct hour of
the day is produced after allowing for daylight savings time
differences and the correct date is given when going from the end
of a long month to a short month.
.PP
The precedence of the applying of single tokens resp. which sequence will be
used by calculating of the time is complex, e. g. heavily dependent on the
precision of type of the token.
.sp
In example below the second date-string contains "next January", therefore
it results in next year but in January. And third date-string besides "January"
contains also additionally "Fri", so it results in the nearest Friday.
Thus both win before "385 days" resp. make it more precise, because of higher
precision of this token types.
.CS
% clock format [clock scan "5 years 18 months 385 days" -base 0 -gmt 1] -gmt 1
Thu Jul 21 00:00:00 GMT 1977
% clock format [clock scan "5 years 18 months 385 days next January" -base 0 -gmt 1] -gmt 1
Sat Jan 21 00:00:00 GMT 1978
% clock format [clock scan "5 years 18 months 385 days next January Fri" -base 0 -gmt 1] -gmt 1
Fri Jan 27 00:00:00 GMT 1978
.CE
.SH "SEE ALSO"
msgcat(n)
.SH KEYWORDS
clock, date, time
.SH "COPYRIGHT"
Copyright \(co 2004 Kevin B. Kenny <[email protected]>. All rights reserved.
'\" Local Variables:
'\" mode: nroff
'\" End:

/*
 * tclClock.c --
 *
 *	Contains the time and date related commands. This code is derived from
 *	the time and date facilities of TclX, by Mark Diekhans and Karl
 *	Lehenbauer.
 *
 * Copyright © 1991-1995 Karl Lehenbauer & Mark Diekhans.
 * Copyright © 1995 Sun Microsystems, Inc.
 * Copyright © 2004 Kevin B. Kenny. All rights reserved.
 * Copyright © 2015 Sergey G. Brester aka sebres. All rights reserved.
 *
 * See the file "license.terms" for information on usage and redistribution of
 * this file, and for a DISCLAIMER OF ALL WARRANTIES.
 */

#include "tclInt.h"
#include "tclTomMath.h"
#include "tclStrIdxTree.h"
#include "tclDate.h"

/*
 * Windows has mktime. The configurators do not check.
 */

#ifdef _WIN32
#define HAVE_MKTIME 1
#endif
















/*
 * Table of the days in each month, leap and common years
 */

static const int hath[2][12] = {
    {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31},
    {31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}
};
static const int daysInPriorMonths[2][13] = {
    {0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365},
    {0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366}
};

/*
 * Enumeration of the string literals used in [clock]
 */
















CLOCK_LITERAL_ARRAY(Literals);



















/* Msgcat literals for exact match (mcKey) */


CLOCK_LOCALE_LITERAL_ARRAY(MsgCtLiterals, "");

/* Msgcat index literals prefixed with _IDX_, used for quick dictionary search */



CLOCK_LOCALE_LITERAL_ARRAY(MsgCtLitIdxs, "_IDX_");




















static const char *const eras[] = { "CE", "BCE", NULL };

/*
 * Thread specific data block holding a 'struct tm' for the 'gmtime' and
 * 'localtime' library calls.
 */

static Tcl_ThreadDataKey tmKey;

/*
 * Mutex protecting 'gmtime', 'localtime' and 'mktime' calls and the statics
 * in the date parsing code.
 */

TCL_DECLARE_MUTEX(clockMutex)

/*
 * Function prototypes for local procedures in this file:
 */



static int		ConvertUTCToLocalUsingTable(Tcl_Interp *,
			    TclDateFields *, Tcl_Size, Tcl_Obj *const[],
			    Tcl_WideInt *rangesVal);
static int		ConvertUTCToLocalUsingC(Tcl_Interp *,
			    TclDateFields *, int);
static int		ConvertLocalToUTC(void *clientData, Tcl_Interp *,
			    TclDateFields *, Tcl_Obj *timezoneObj, int);
static int		ConvertLocalToUTCUsingTable(Tcl_Interp *,
			    TclDateFields *, int, Tcl_Obj *const[],
			    Tcl_WideInt *rangesVal);
static int		ConvertLocalToUTCUsingC(Tcl_Interp *,
			    TclDateFields *, int);
static int		ClockConfigureObjCmd(void *clientData,
			    Tcl_Interp *interp, int objc, Tcl_Obj *const objv[]);
static void		GetYearWeekDay(TclDateFields *, int);
static void		GetGregorianEraYearDay(TclDateFields *, int);
static void		GetMonthDay(TclDateFields *);



static Tcl_WideInt	WeekdayOnOrBefore(int, Tcl_WideInt);
static Tcl_ObjCmdProc ClockClicksObjCmd;
static Tcl_ObjCmdProc ClockConvertlocaltoutcObjCmd;

static int		ClockGetDateFields(void *clientData,
			    Tcl_Interp *interp, TclDateFields *fields,
			    Tcl_Obj *timezoneObj, int changeover);
static Tcl_ObjCmdProc ClockGetdatefieldsObjCmd;
static Tcl_ObjCmdProc ClockGetjuliandayfromerayearmonthdayObjCmd;
static Tcl_ObjCmdProc ClockGetjuliandayfromerayearweekdayObjCmd;
static Tcl_ObjCmdProc ClockGetenvObjCmd;
static Tcl_ObjCmdProc ClockMicrosecondsObjCmd;
static Tcl_ObjCmdProc ClockMillisecondsObjCmd;
static Tcl_ObjCmdProc ClockSecondsObjCmd;
static Tcl_ObjCmdProc ClockFormatObjCmd;
static Tcl_ObjCmdProc ClockScanObjCmd;
static int		ClockScanCommit(
			    DateInfo *info,
			    ClockFmtScnCmdArgs *opts);
static int		ClockFreeScan(
			    DateInfo *info,
			    Tcl_Obj *strObj, ClockFmtScnCmdArgs *opts);
static int		ClockCalcRelTime(
			    DateInfo *info);
static Tcl_ObjCmdProc ClockAddObjCmd;
static int		ClockValidDate(
			    DateInfo *,
			    ClockFmtScnCmdArgs *, int stage);
static struct tm *	ThreadSafeLocalTime(const time_t *);
static size_t		TzsetIfNecessary(void);
static void		ClockDeleteCmdProc(void *);

static Tcl_ObjCmdProc ClockSafeCatchCmd;
/*
 * Structure containing description of "native" clock commands to create.
 */

struct ClockCommand {
    const char *name;		/* The tail of the command name. The full name
				 * is "::tcl::clock::<name>". When NULL marks
				 * the end of the table. */
    Tcl_ObjCmdProc *objCmdProc; /* Function that implements the command. This
				 * will always have the ClockClientData sent
				 * to it, but may well ignore this data. */
    CompileProc *compileProc;	/* The compiler for the command. */
    void *clientData;	/* Any clientData to give the command (if NULL
    				 * a reference to ClockClientData will be sent) */
};

static const struct ClockCommand clockCommands[] = {
    {"add",		ClockAddObjCmd,		TclCompileBasicMin1ArgCmd, NULL},
    {"clicks",		ClockClicksObjCmd,	TclCompileClockClicksCmd,  NULL},
    {"format",		ClockFormatObjCmd,	TclCompileBasicMin1ArgCmd, NULL},
    {"getenv",		ClockGetenvObjCmd,	TclCompileBasicMin1ArgCmd, NULL},
    {"microseconds",	ClockMicrosecondsObjCmd,TclCompileClockReadingCmd, INT2PTR(1)},
    {"milliseconds",	ClockMillisecondsObjCmd,TclCompileClockReadingCmd, INT2PTR(2)},
    {"scan",		ClockScanObjCmd,	TclCompileBasicMin1ArgCmd, NULL},
    {"seconds",		ClockSecondsObjCmd,	TclCompileClockReadingCmd, INT2PTR(3)},
    {"ConvertLocalToUTC", ClockConvertlocaltoutcObjCmd,		NULL, NULL},
    {"GetDateFields",	  ClockGetdatefieldsObjCmd,		NULL, NULL},
    {"GetJulianDayFromEraYearMonthDay",
		ClockGetjuliandayfromerayearmonthdayObjCmd,	NULL, NULL},
    {"GetJulianDayFromEraYearWeekDay",
		ClockGetjuliandayfromerayearweekdayObjCmd,	NULL, NULL},

    {"catch",		ClockSafeCatchCmd,	TclCompileBasicMin1ArgCmd, NULL},
    {NULL, NULL, NULL, NULL}
};

/*
 *----------------------------------------------------------------------
 *
 * TclClockInit --
 *

TclClockInit(
    Tcl_Interp *interp)		/* Tcl interpreter */
{
    const struct ClockCommand *clockCmdPtr;
    char cmdName[50];		/* Buffer large enough to hold the string
				 *::tcl::clock::GetJulianDayFromEraYearMonthDay
				 * plus a terminating NUL. */
    Command         *cmdPtr;
    ClockClientData *data;
    int i;














    /*
     * Safe interps get [::clock] as alias to a parent, so do not need their
     * own copies of the support routines.
     */

    if (Tcl_IsSafe(interp)) {
	return;
    }

    /*
     * Create the client data, which is a refcounted literal pool.
     */

    data = (ClockClientData *)ckalloc(sizeof(ClockClientData));
    data->refCount = 0;
    data->literals = (Tcl_Obj **)ckalloc(LIT__END * sizeof(Tcl_Obj*));
    for (i = 0; i < LIT__END; ++i) {
	TclInitObjRef(data->literals[i], Tcl_NewStringObj(Literals[i], -1));
    }
    data->mcLiterals = NULL;
    data->mcLitIdxs = NULL;
    data->mcDicts = NULL;
    data->lastTZEpoch = 0;
    data->currentYearCentury = ClockDefaultYearCentury;
    data->yearOfCenturySwitch = ClockDefaultCenturySwitch;
    data->validMinYear = INT_MIN;
    data->validMaxYear = INT_MAX;
    /* corresponds max of JDN in sqlite - 9999-12-31 23:59:59 per default */
    data->maxJDN = 5373484.499999994;

    data->systemTimeZone = NULL;
    data->systemSetupTZData = NULL;
    data->gmtSetupTimeZoneUnnorm = NULL;
    data->gmtSetupTimeZone = NULL;
    data->gmtSetupTZData = NULL;
    data->gmtTZName = NULL;
    data->lastSetupTimeZoneUnnorm = NULL;
    data->lastSetupTimeZone = NULL;
    data->lastSetupTZData = NULL;
    data->prevSetupTimeZoneUnnorm = NULL;
    data->prevSetupTimeZone = NULL;
    data->prevSetupTZData = NULL;

    data->defaultLocale = NULL;
    data->defaultLocaleDict = NULL;
    data->currentLocale = NULL;
    data->currentLocaleDict = NULL;
    data->lastUsedLocaleUnnorm = NULL;
    data->lastUsedLocale = NULL;
    data->lastUsedLocaleDict = NULL;
    data->prevUsedLocaleUnnorm = NULL;
    data->prevUsedLocale = NULL;
    data->prevUsedLocaleDict = NULL;

    data->lastBase.timezoneObj = NULL;

    memset(&data->lastTZOffsCache, 0, sizeof(data->lastTZOffsCache));

    data->defFlags = 0;

    /*
     * Install the commands.

     */

#define TCL_CLOCK_PREFIX_LEN 14 /* == strlen("::tcl::clock::") */
    memcpy(cmdName, "::tcl::clock::", TCL_CLOCK_PREFIX_LEN);
    for (clockCmdPtr=clockCommands ; clockCmdPtr->name!=NULL ; clockCmdPtr++) {
    	void *clientData;

	strcpy(cmdName + TCL_CLOCK_PREFIX_LEN, clockCmdPtr->name);
	if (!(clientData = clockCmdPtr->clientData)) {
	    clientData = data;
	    data->refCount++;
	}
	cmdPtr = (Command *)Tcl_CreateObjCommand(interp, cmdName,
		clockCmdPtr->objCmdProc, clientData,
		clockCmdPtr->clientData ? NULL : ClockDeleteCmdProc);
	cmdPtr->compileProc = clockCmdPtr->compileProc ?
		clockCmdPtr->compileProc : TclCompileBasicMin0ArgCmd;
    }
    cmdPtr = (Command *)Tcl_CreateObjCommand(interp,
	    "::tcl::unsupported::clock::configure",
	    ClockConfigureObjCmd, data, ClockDeleteCmdProc);
    data->refCount++;
    cmdPtr->compileProc = TclCompileBasicMin0ArgCmd;
}

/*
 *----------------------------------------------------------------------
 *
 * ClockConfigureClear --
 *
 *	Clean up cached resp. run-time storages used in clock commands.
 *
 *	Shared usage for clean-up (ClockDeleteCmdProc) and "configure -clear".
 *
 * Results:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static void
ClockConfigureClear(
    ClockClientData *data)
{
    ClockFrmScnClearCaches();

    data->lastTZEpoch = 0;
    TclUnsetObjRef(data->systemTimeZone);
    TclUnsetObjRef(data->systemSetupTZData);
    TclUnsetObjRef(data->gmtSetupTimeZoneUnnorm);
    TclUnsetObjRef(data->gmtSetupTimeZone);
    TclUnsetObjRef(data->gmtSetupTZData);
    TclUnsetObjRef(data->gmtTZName);
    TclUnsetObjRef(data->lastSetupTimeZoneUnnorm);
    TclUnsetObjRef(data->lastSetupTimeZone);
    TclUnsetObjRef(data->lastSetupTZData);
    TclUnsetObjRef(data->prevSetupTimeZoneUnnorm);
    TclUnsetObjRef(data->prevSetupTimeZone);
    TclUnsetObjRef(data->prevSetupTZData);

    TclUnsetObjRef(data->defaultLocale);
    data->defaultLocaleDict = NULL;
    TclUnsetObjRef(data->currentLocale);
    data->currentLocaleDict = NULL;
    TclUnsetObjRef(data->lastUsedLocaleUnnorm);
    TclUnsetObjRef(data->lastUsedLocale);
    data->lastUsedLocaleDict = NULL;
    TclUnsetObjRef(data->prevUsedLocaleUnnorm);
    TclUnsetObjRef(data->prevUsedLocale);
    data->prevUsedLocaleDict = NULL;

    TclUnsetObjRef(data->lastBase.timezoneObj);

    TclUnsetObjRef(data->lastTZOffsCache[0].timezoneObj);
    TclUnsetObjRef(data->lastTZOffsCache[0].tzName);
    TclUnsetObjRef(data->lastTZOffsCache[1].timezoneObj);
    TclUnsetObjRef(data->lastTZOffsCache[1].tzName);

    TclUnsetObjRef(data->mcDicts);
}

/*
 *----------------------------------------------------------------------
 *
 * ClockDeleteCmdProc --
 *
 *	Remove a reference to the clock client data, and clean up memory
 *	when it's all gone.
 *
 * Results:
 *	None.
 *
 *----------------------------------------------------------------------
 */
static void
ClockDeleteCmdProc(
    void *clientData)	/* Opaque pointer to the client data */
{
    ClockClientData *data = (ClockClientData *)clientData;
    int i;

    if (data->refCount-- <= 1) {
	for (i = 0; i < LIT__END; ++i) {
	    Tcl_DecrRefCount(data->literals[i]);
	}
	if (data->mcLiterals != NULL) {
	    for (i = 0; i < MCLIT__END; ++i) {
		Tcl_DecrRefCount(data->mcLiterals[i]);
	    }
	    data->mcLiterals = NULL;
	}
	if (data->mcLitIdxs != NULL) {
	    for (i = 0; i < MCLIT__END; ++i) {
		Tcl_DecrRefCount(data->mcLitIdxs[i]);
	    }
	    data->mcLitIdxs = NULL;
	}

	ClockConfigureClear(data);

	ckfree(data->literals);
	ckfree(data);
    }
}

/*
 *----------------------------------------------------------------------
 *
 * SavePrevTimezoneObj --
 *
 *	Used to store previously used/cached time zone (makes it reusable).
 *
 *	This enables faster switch between time zones (e. g. to convert from one to another).
 *
 * Results:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static inline void
SavePrevTimezoneObj(
    ClockClientData *dataPtr)	/* Client data containing literal pool */
{
    Tcl_Obj *timezoneObj = dataPtr->lastSetupTimeZone;
    if (timezoneObj && timezoneObj != dataPtr->prevSetupTimeZone) {
	TclSetObjRef(dataPtr->prevSetupTimeZoneUnnorm, dataPtr->lastSetupTimeZoneUnnorm);
	TclSetObjRef(dataPtr->prevSetupTimeZone, timezoneObj);
	TclSetObjRef(dataPtr->prevSetupTZData, dataPtr->lastSetupTZData);
    }
}

/*
 *----------------------------------------------------------------------
 *
 * NormTimezoneObj --
 *
 *	Normalizes the timezone object (used for caching puposes).
 *
 *	If already cached time zone could be found, returns this
 *	object (last setup or last used, system (current) or gmt).
 *
 * Results:
 *	Normalized tcl object pointer.
 *
 *----------------------------------------------------------------------
 */

static Tcl_Obj *
NormTimezoneObj(
    ClockClientData *dataPtr,	/* Client data containing literal pool */
    Tcl_Obj	*timezoneObj,	/* Name of zone to find */
    int		*loaded)	/* Used to recognized TZ was loaded */
{
    const char *tz;

    *loaded = 1;
    if ( timezoneObj == dataPtr->lastSetupTimeZoneUnnorm
      && dataPtr->lastSetupTimeZone != NULL
    ) {
	return dataPtr->lastSetupTimeZone;
    }
    if ( timezoneObj == dataPtr->prevSetupTimeZoneUnnorm
      && dataPtr->prevSetupTimeZone != NULL
    ) {
    	return dataPtr->prevSetupTimeZone;
    }
    if (timezoneObj == dataPtr->gmtSetupTimeZoneUnnorm
      && dataPtr->gmtSetupTimeZone != NULL
    ) {
	return dataPtr->literals[LIT_GMT];
    }
    if ( timezoneObj == dataPtr->lastSetupTimeZone
      || timezoneObj == dataPtr->prevSetupTimeZone
      || timezoneObj == dataPtr->gmtSetupTimeZone
      || timezoneObj == dataPtr->systemTimeZone
    ) {
	return timezoneObj;
    }

    tz = TclGetString(timezoneObj);
    if (dataPtr->lastSetupTimeZone != NULL &&
	strcmp(tz, TclGetString(dataPtr->lastSetupTimeZone)) == 0
    ) {
	TclSetObjRef(dataPtr->lastSetupTimeZoneUnnorm, timezoneObj);
	return dataPtr->lastSetupTimeZone;
    }
    if (dataPtr->prevSetupTimeZone != NULL &&
	strcmp(tz, TclGetString(dataPtr->prevSetupTimeZone)) == 0
    ) {
	TclSetObjRef(dataPtr->prevSetupTimeZoneUnnorm, timezoneObj);
	return dataPtr->prevSetupTimeZone;
    }
    if (dataPtr->systemTimeZone != NULL &&
	strcmp(tz, TclGetString(dataPtr->systemTimeZone)) == 0
    ) {
	return dataPtr->systemTimeZone;
    }
    if (strcmp(tz, Literals[LIT_GMT]) == 0) {
	TclSetObjRef(dataPtr->gmtSetupTimeZoneUnnorm, timezoneObj);
	if (dataPtr->gmtSetupTimeZone == NULL) {
	    *loaded = 0;
	}
	return dataPtr->literals[LIT_GMT];
    }
    /* unknown/unloaded tz - recache/revalidate later as last-setup if needed */
    *loaded = 0;
    return timezoneObj;
}

/*
 *----------------------------------------------------------------------
 *
 * ClockGetSystemLocale --
 *
 *	Returns system locale.
 *
 *	Executes ::tcl::clock::GetSystemLocale in given interpreter.
 *
 * Results:
 *	Returns system locale tcl object.
 *
 *----------------------------------------------------------------------
 */

static inline Tcl_Obj *
ClockGetSystemLocale(
    ClockClientData *dataPtr,	/* Opaque pointer to literal pool, etc. */
    Tcl_Interp *interp)		/* Tcl interpreter */
{
    if (Tcl_EvalObjv(interp, 1, &dataPtr->literals[LIT_GETSYSTEMLOCALE], 0) != TCL_OK) {
	return NULL;
    }

    return Tcl_GetObjResult(interp);
}
/*
 *----------------------------------------------------------------------
 *
 * ClockGetCurrentLocale --
 *
 *	Returns current locale.
 *
 *	Executes ::tcl::clock::mclocale in given interpreter.
 *
 * Results:
 *	Returns current locale tcl object.
 *
 *----------------------------------------------------------------------
 */

static inline Tcl_Obj *
ClockGetCurrentLocale(
    ClockClientData *dataPtr,	/* Client data containing literal pool */
    Tcl_Interp *interp)		/* Tcl interpreter */
{
    if (Tcl_EvalObjv(interp, 1, &dataPtr->literals[LIT_GETCURRENTLOCALE], 0) != TCL_OK) {
	return NULL;
    }

    TclSetObjRef(dataPtr->currentLocale, Tcl_GetObjResult(interp));
    dataPtr->currentLocaleDict = NULL;
    Tcl_ResetResult(interp);

    return dataPtr->currentLocale;
}

/*
 *----------------------------------------------------------------------
 *
 * SavePrevLocaleObj --
 *
 *	Used to store previously used/cached locale (makes it reusable).
 *
 *	This enables faster switch between locales (e. g. to convert from one to another).
 *
 * Results:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static inline void
SavePrevLocaleObj(
    ClockClientData *dataPtr)	/* Client data containing literal pool */
{
    Tcl_Obj *localeObj = dataPtr->lastUsedLocale;
    if (localeObj && localeObj != dataPtr->prevUsedLocale) {
	TclSetObjRef(dataPtr->prevUsedLocaleUnnorm, dataPtr->lastUsedLocaleUnnorm);
	TclSetObjRef(dataPtr->prevUsedLocale, localeObj);
	/* mcDicts owns reference to dict */
	dataPtr->prevUsedLocaleDict = dataPtr->lastUsedLocaleDict;
    }
}

/*
 *----------------------------------------------------------------------
 *
 * NormLocaleObj --
 *
 *	Normalizes the locale object (used for caching puposes).
 *
 *	If already cached locale could be found, returns this
 *	object (current, system (OS) or last used locales).
 *
 * Results:
 *	Normalized tcl object pointer.
 *
 *----------------------------------------------------------------------
 */

static Tcl_Obj *
NormLocaleObj(
    ClockClientData *dataPtr,	/* Client data containing literal pool */
    Tcl_Interp *interp,		/* Tcl interpreter */
    Tcl_Obj    *localeObj,
    Tcl_Obj   **mcDictObj)
{
    const char *loc, *loc2;
    if ( localeObj == NULL
      || localeObj == dataPtr->literals[LIT_C]
      || localeObj == dataPtr->defaultLocale
    ) {
	*mcDictObj = dataPtr->defaultLocaleDict;
	return dataPtr->defaultLocale ?
		    dataPtr->defaultLocale : dataPtr->literals[LIT_C];
    }
    if ( localeObj == dataPtr->currentLocale
      || localeObj == dataPtr->literals[LIT_CURRENT]
    ) {
	if (dataPtr->currentLocale == NULL) {
	    ClockGetCurrentLocale(dataPtr, interp);
	}
	*mcDictObj = dataPtr->currentLocaleDict;
	return dataPtr->currentLocale;
    }
    if ( localeObj == dataPtr->lastUsedLocale
      || localeObj == dataPtr->lastUsedLocaleUnnorm
    ) {
	*mcDictObj = dataPtr->lastUsedLocaleDict;
	return dataPtr->lastUsedLocale;
    }
    if ( localeObj == dataPtr->prevUsedLocale
      || localeObj == dataPtr->prevUsedLocaleUnnorm
    ) {
	*mcDictObj = dataPtr->prevUsedLocaleDict;
	return dataPtr->prevUsedLocale;
    }

    loc = TclGetString(localeObj);
    if ( dataPtr->currentLocale != NULL
      && ( localeObj == dataPtr->currentLocale
       || (localeObj->length == dataPtr->currentLocale->length
	  && strcasecmp(loc, TclGetString(dataPtr->currentLocale)) == 0
	)
      )
    ) {
	*mcDictObj = dataPtr->currentLocaleDict;
	return dataPtr->currentLocale;
    }
    if ( dataPtr->lastUsedLocale != NULL
      && ( localeObj == dataPtr->lastUsedLocale
       || (localeObj->length == dataPtr->lastUsedLocale->length
	  && strcasecmp(loc, TclGetString(dataPtr->lastUsedLocale)) == 0
	)
      )
    ) {
	*mcDictObj = dataPtr->lastUsedLocaleDict;
	TclSetObjRef(dataPtr->lastUsedLocaleUnnorm, localeObj);
	return dataPtr->lastUsedLocale;
    }
    if ( dataPtr->prevUsedLocale != NULL
      && ( localeObj == dataPtr->prevUsedLocale
       || (localeObj->length == dataPtr->prevUsedLocale->length
	  && strcasecmp(loc, TclGetString(dataPtr->prevUsedLocale)) == 0
	)
      )
    ) {
	*mcDictObj = dataPtr->prevUsedLocaleDict;
	TclSetObjRef(dataPtr->prevUsedLocaleUnnorm, localeObj);
	return dataPtr->prevUsedLocale;
    }
    if (
	 (localeObj->length == 1 /* C */
	   && strcasecmp(loc, Literals[LIT_C]) == 0)
      || (dataPtr->defaultLocale && (loc2 = TclGetString(dataPtr->defaultLocale))
      	   && localeObj->length == dataPtr->defaultLocale->length
	   && strcasecmp(loc, loc2) == 0)
    ) {
	*mcDictObj = dataPtr->defaultLocaleDict;
	return dataPtr->defaultLocale ?
		    dataPtr->defaultLocale : dataPtr->literals[LIT_C];
    }
    if ( localeObj->length == 7 /* current */
      && strcasecmp(loc, Literals[LIT_CURRENT]) == 0
    ) {
	if (dataPtr->currentLocale == NULL) {
	    ClockGetCurrentLocale(dataPtr, interp);
	}
	*mcDictObj = dataPtr->currentLocaleDict;
	return dataPtr->currentLocale;
    }
    if (
	 (localeObj->length == 6 /* system */
	   && strcasecmp(loc, Literals[LIT_SYSTEM]) == 0)
    ) {
	SavePrevLocaleObj(dataPtr);
	TclSetObjRef(dataPtr->lastUsedLocaleUnnorm, localeObj);
	localeObj = ClockGetSystemLocale(dataPtr, interp);
	TclSetObjRef(dataPtr->lastUsedLocale, localeObj);
	*mcDictObj = NULL;
	return localeObj;
    }
    *mcDictObj = NULL;
    return localeObj;
}

/*
 *----------------------------------------------------------------------
 *
 * ClockMCDict --
 *
 *	Retrieves a localized storage dictionary object for the given
 *	locale object.
 *
 *	This corresponds with call `::tcl::clock::mcget locale`.
 *	Cached representation stored in options (for further access).
 *
 * Results:
 *	Tcl-object contains smart reference to msgcat dictionary.
 *
 *----------------------------------------------------------------------
 */

Tcl_Obj *
ClockMCDict(ClockFmtScnCmdArgs *opts)
{
    ClockClientData *dataPtr = (ClockClientData *)opts->clientData;

    /* if dict not yet retrieved */
    if (opts->mcDictObj == NULL) {

	/* if locale was not yet used */
	if ( !(opts->flags & CLF_LOCALE_USED) ) {

	    opts->localeObj = NormLocaleObj((ClockClientData *)opts->clientData, opts->interp,
		opts->localeObj, &opts->mcDictObj);

	    if (opts->localeObj == NULL) {
		Tcl_SetObjResult(opts->interp,
		    Tcl_NewStringObj("locale not specified and no default locale set", -1));
		Tcl_SetErrorCode(opts->interp, "CLOCK", "badOption", (char *)NULL);
		return NULL;
	    }
	    opts->flags |= CLF_LOCALE_USED;

	    /* check locale literals already available (on demand creation) */
	    if (dataPtr->mcLiterals == NULL) {
		int i;
		dataPtr->mcLiterals = (Tcl_Obj **)ckalloc(MCLIT__END * sizeof(Tcl_Obj*));
		for (i = 0; i < MCLIT__END; ++i) {
		    TclInitObjRef(dataPtr->mcLiterals[i],
			Tcl_NewStringObj(MsgCtLiterals[i], -1));
		}
	    }
	}

	/* check or obtain mcDictObj (be sure it's modifiable) */
	if (opts->mcDictObj == NULL || opts->mcDictObj->refCount > 1) {
	    int ref = 1;

	    /* first try to find locale catalog dict */
	    if (dataPtr->mcDicts == NULL) {
		TclSetObjRef(dataPtr->mcDicts, Tcl_NewDictObj());
	    }
	    Tcl_DictObjGet(NULL, dataPtr->mcDicts,
		opts->localeObj, &opts->mcDictObj);

	    if (opts->mcDictObj == NULL) {
		/* get msgcat dictionary - ::tcl::clock::mcget locale */
		Tcl_Obj *callargs[2];

		callargs[0] = dataPtr->literals[LIT_MCGET];
		callargs[1] = opts->localeObj;

		if (Tcl_EvalObjv(opts->interp, 2, callargs, 0) != TCL_OK) {
		    return NULL;
		}

		opts->mcDictObj = Tcl_GetObjResult(opts->interp);
		Tcl_ResetResult(opts->interp);
		ref = 0; /* new object is not yet referenced */
	    }

	    /* be sure that object reference doesn't increase (dict changeable) */
	    if (opts->mcDictObj->refCount > ref) {
		/* smart reference (shared dict as object with no ref-counter) */
		opts->mcDictObj = TclDictObjSmartRef(opts->interp,
		    opts->mcDictObj);
	    }

	    /* create exactly one reference to catalog / make it searchable for future */
	    Tcl_DictObjPut(NULL, dataPtr->mcDicts, opts->localeObj,
		opts->mcDictObj);

	    if ( opts->localeObj == dataPtr->literals[LIT_C]
	      || opts->localeObj == dataPtr->defaultLocale
	    ) {
		dataPtr->defaultLocaleDict = opts->mcDictObj;
	    }
	    if ( opts->localeObj == dataPtr->currentLocale ) {
		dataPtr->currentLocaleDict = opts->mcDictObj;
	    } else if ( opts->localeObj == dataPtr->lastUsedLocale ) {
		dataPtr->lastUsedLocaleDict = opts->mcDictObj;
	    } else {
		SavePrevLocaleObj(dataPtr);
		TclSetObjRef(dataPtr->lastUsedLocale, opts->localeObj);
		TclUnsetObjRef(dataPtr->lastUsedLocaleUnnorm);
		dataPtr->lastUsedLocaleDict = opts->mcDictObj;
	    }
	}
    }

    return opts->mcDictObj;
}

/*
 *----------------------------------------------------------------------
 *
 * ClockMCGet --
 *
 *	Retrieves a msgcat value for the given literal integer mcKey
 *	from localized storage (corresponding given locale object)
 *	by mcLiterals[mcKey] (e. g. MONTHS_FULL).
 *
 * Results:
 *	Tcl-object contains localized value.
 *
 *----------------------------------------------------------------------
 */

Tcl_Obj *
ClockMCGet(
    ClockFmtScnCmdArgs *opts,
    int mcKey)
{
    ClockClientData *dataPtr = (ClockClientData *)opts->clientData;

    Tcl_Obj *valObj = NULL;

    if (opts->mcDictObj == NULL) {
	ClockMCDict(opts);
	if (opts->mcDictObj == NULL)
	    return NULL;
    }

    Tcl_DictObjGet(opts->interp, opts->mcDictObj,
	dataPtr->mcLiterals[mcKey], &valObj);

    return valObj; /* or NULL in obscure case if Tcl_DictObjGet failed */
}

/*
 *----------------------------------------------------------------------
 *
 * ClockMCGetIdx --
 *
 *	Retrieves an indexed msgcat value for the given literal integer mcKey
 *	from localized storage (corresponding given locale object)
 *	by mcLitIdxs[mcKey] (e. g. _IDX_MONTHS_FULL).
 *
 * Results:
 *	Tcl-object contains localized indexed value.
 *
 *----------------------------------------------------------------------
 */

MODULE_SCOPE Tcl_Obj *
ClockMCGetIdx(
    ClockFmtScnCmdArgs *opts,
    int mcKey)
{
    ClockClientData *dataPtr = (ClockClientData *)opts->clientData;

    Tcl_Obj *valObj = NULL;

    if (opts->mcDictObj == NULL) {
	ClockMCDict(opts);
	if (opts->mcDictObj == NULL)
	    return NULL;
    }

    /* try to get indices object */
    if (dataPtr->mcLitIdxs == NULL) {
	return NULL;
    }

    if (Tcl_DictObjGet(NULL, opts->mcDictObj,
	dataPtr->mcLitIdxs[mcKey], &valObj) != TCL_OK
    ) {
	return NULL;
    }

    return valObj;
}

/*
 *----------------------------------------------------------------------
 *
 * ClockMCSetIdx --
 *
 *	Sets an indexed msgcat value for the given literal integer mcKey
 *	in localized storage (corresponding given locale object)
 *	by mcLitIdxs[mcKey] (e. g. _IDX_MONTHS_FULL).
 *
 * Results:
 *	Returns a standard Tcl result.
 *
 *----------------------------------------------------------------------
 */

int
ClockMCSetIdx(
    ClockFmtScnCmdArgs *opts,
    int mcKey, Tcl_Obj *valObj)
{
    ClockClientData *dataPtr = (ClockClientData *)opts->clientData;

    if (opts->mcDictObj == NULL) {
	ClockMCDict(opts);
	if (opts->mcDictObj == NULL)
	    return TCL_ERROR;
    }

    /* if literal storage for indices not yet created */
    if (dataPtr->mcLitIdxs == NULL) {
	int i;
	dataPtr->mcLitIdxs = (Tcl_Obj **)ckalloc(MCLIT__END * sizeof(Tcl_Obj*));
	for (i = 0; i < MCLIT__END; ++i) {
	    TclInitObjRef(dataPtr->mcLitIdxs[i],
		Tcl_NewStringObj(MsgCtLitIdxs[i], -1));
	}
    }

    return Tcl_DictObjPut(opts->interp, opts->mcDictObj,
	    dataPtr->mcLitIdxs[mcKey], valObj);
}

static void
TimezoneLoaded(
    ClockClientData *dataPtr,
    Tcl_Obj	*timezoneObj,	/* Name of zone was loaded */
    Tcl_Obj	*tzUnnormObj)	/* Name of zone was loaded */
{
    /* don't overwrite last-setup with GMT (special case) */
    if (timezoneObj == dataPtr->literals[LIT_GMT]) {
	/* mark GMT zone loaded */
	if (dataPtr->gmtSetupTimeZone == NULL) {
	    TclSetObjRef(dataPtr->gmtSetupTimeZone,
		dataPtr->literals[LIT_GMT]);
	}
	TclSetObjRef(dataPtr->gmtSetupTimeZoneUnnorm, tzUnnormObj);
	return;
    }

    /* last setup zone loaded */
    if (dataPtr->lastSetupTimeZone != timezoneObj) {
	SavePrevTimezoneObj(dataPtr);
	TclSetObjRef(dataPtr->lastSetupTimeZone, timezoneObj);
	TclUnsetObjRef(dataPtr->lastSetupTZData);
    }
    TclSetObjRef(dataPtr->lastSetupTimeZoneUnnorm, tzUnnormObj);
}
/*
 *----------------------------------------------------------------------
 *
 * ClockConfigureObjCmd --
 *
 *	This function is invoked to process the Tcl "::clock::configure" (internal) command.
 *
 * Usage:
 *	::tcl::unsupported::clock::configure ?-option ?value??
 *
 * Results:
 *	Returns a standard Tcl result.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static int
ClockConfigureObjCmd(
    void *clientData,  /* Client data containing literal pool */
    Tcl_Interp *interp,	    /* Tcl interpreter */
    int objc,		    /* Parameter count */
    Tcl_Obj *const objv[])  /* Parameter vector */
{
    ClockClientData *dataPtr = (ClockClientData *)clientData;

    static const char *const options[] = {
	"-system-tz",	  "-setup-tz",	  "-default-locale",	"-current-locale",
	"-clear",
	"-year-century",  "-century-switch",
	"-min-year", "-max-year", "-max-jdn", "-validate",
	"-init-complete",
	NULL
    };
    enum optionInd {
	CLOCK_SYSTEM_TZ,  CLOCK_SETUP_TZ, CLOCK_DEFAULT_LOCALE, CLOCK_CURRENT_LOCALE,
	CLOCK_CLEAR_CACHE,
	CLOCK_YEAR_CENTURY, CLOCK_CENTURY_SWITCH,
	CLOCK_MIN_YEAR, CLOCK_MAX_YEAR, CLOCK_MAX_JDN, CLOCK_VALIDATE,
	CLOCK_INIT_COMPLETE
    };
    int optionIndex;		/* Index of an option. */
    int i;

    for (i = 1; i < objc; i++) {
	if (Tcl_GetIndexFromObj(interp, objv[i++], options,
	    "option", 0, &optionIndex) != TCL_OK) {
	    Tcl_SetErrorCode(interp, "CLOCK", "badOption",
		    Tcl_GetString(objv[i-1]), (char *)NULL);
	    return TCL_ERROR;
	}
	switch (optionIndex) {
	case CLOCK_SYSTEM_TZ: {
	    /* validate current tz-epoch */
	    size_t lastTZEpoch = TzsetIfNecessary();
	    if (i < objc) {
		if (dataPtr->systemTimeZone != objv[i]) {
		    TclSetObjRef(dataPtr->systemTimeZone, objv[i]);
		    TclUnsetObjRef(dataPtr->systemSetupTZData);
		}
		dataPtr->lastTZEpoch = lastTZEpoch;
	    }
	    if (i+1 >= objc && dataPtr->systemTimeZone != NULL
			 && dataPtr->lastTZEpoch == lastTZEpoch) {
		Tcl_SetObjResult(interp, dataPtr->systemTimeZone);
	    }
	}
	break;
	case CLOCK_SETUP_TZ:
	    if (i < objc) {
		int loaded;
		Tcl_Obj *timezoneObj = NormTimezoneObj(dataPtr, objv[i], &loaded);
		if (!loaded) {
		    TimezoneLoaded(dataPtr, timezoneObj, objv[i]);
		}
		Tcl_SetObjResult(interp, timezoneObj);
	    }
	    else
	    if (i+1 >= objc && dataPtr->lastSetupTimeZone != NULL) {
		Tcl_SetObjResult(interp, dataPtr->lastSetupTimeZone);
	    }
	break;
	case CLOCK_DEFAULT_LOCALE:
	    if (i < objc) {
		if (dataPtr->defaultLocale != objv[i]) {
		    TclSetObjRef(dataPtr->defaultLocale, objv[i]);
		    dataPtr->defaultLocaleDict = NULL;
		}
	    }
	    if (i+1 >= objc) {
		Tcl_SetObjResult(interp, dataPtr->defaultLocale ?
		    dataPtr->defaultLocale : dataPtr->literals[LIT_C]);
	    }
	break;
	case CLOCK_CURRENT_LOCALE:
	    if (i < objc) {
		if (dataPtr->currentLocale != objv[i]) {
		    TclSetObjRef(dataPtr->currentLocale, objv[i]);
		    dataPtr->currentLocaleDict = NULL;
		}
	    }
	    if (i+1 >= objc && dataPtr->currentLocale != NULL) {
		Tcl_SetObjResult(interp, dataPtr->currentLocale);
	    }
	break;
	case CLOCK_YEAR_CENTURY:
	    if (i < objc) {
		int year;
		if (TclGetIntFromObj(interp, objv[i], &year) != TCL_OK) {
		    return TCL_ERROR;
		}
		dataPtr->currentYearCentury = year;
		if (i+1 >= objc) {
		    Tcl_SetObjResult(interp, objv[i]);
		}
		continue;
	    }
	    if (i+1 >= objc) {
		Tcl_SetObjResult(interp,
		    Tcl_NewWideIntObj(dataPtr->currentYearCentury));
	    }
	break;
	case CLOCK_CENTURY_SWITCH:
	    if (i < objc) {
		int year;
		if (TclGetIntFromObj(interp, objv[i], &year) != TCL_OK) {
		    return TCL_ERROR;
		}
		dataPtr->yearOfCenturySwitch = year;
		Tcl_SetObjResult(interp, objv[i]);
		continue;
	    }
	    if (i+1 >= objc) {
		Tcl_SetObjResult(interp,
		    Tcl_NewWideIntObj(dataPtr->yearOfCenturySwitch));
	    }
	break;
	case CLOCK_MIN_YEAR:
	    if (i < objc) {
		int year;
		if (TclGetIntFromObj(interp, objv[i], &year) != TCL_OK) {
		    return TCL_ERROR;
		}
		dataPtr->validMinYear = year;
		Tcl_SetObjResult(interp, objv[i]);
		continue;
	    }
	    if (i+1 >= objc) {
		Tcl_SetObjResult(interp,
		    Tcl_NewWideIntObj(dataPtr->validMinYear));
	    }
	break;
	case CLOCK_MAX_YEAR:
	    if (i < objc) {
		int year;
		if (TclGetIntFromObj(interp, objv[i], &year) != TCL_OK) {
		    return TCL_ERROR;
		}
		dataPtr->validMaxYear = year;
		Tcl_SetObjResult(interp, objv[i]);
		continue;
	    }
	    if (i+1 >= objc) {
		Tcl_SetObjResult(interp,
		    Tcl_NewWideIntObj(dataPtr->validMaxYear));
	    }
	break;
	case CLOCK_MAX_JDN:
	    if (i < objc) {
		double jd;
		if (Tcl_GetDoubleFromObj(interp, objv[i], &jd) != TCL_OK) {
		    return TCL_ERROR;
		}
		dataPtr->maxJDN = jd;
		Tcl_SetObjResult(interp, objv[i]);
		continue;
	    }
	    if (i+1 >= objc) {
		Tcl_SetObjResult(interp,
		    Tcl_NewDoubleObj(dataPtr->maxJDN));
	    }
	break;
	case CLOCK_VALIDATE:
	    if (i < objc) {
		int val;
		if (Tcl_GetBooleanFromObj(interp, objv[i], &val) != TCL_OK) {
		    return TCL_ERROR;
		}
		if (val) {
		    dataPtr->defFlags |= CLF_VALIDATE;
		} else {
		    dataPtr->defFlags &= ~CLF_VALIDATE;
		}
	    }
	    if (i+1 >= objc) {
		Tcl_SetObjResult(interp,
		    Tcl_NewWideIntObj(dataPtr->defFlags & CLF_VALIDATE ? 1 : 0));
	    }
	break;
	case CLOCK_CLEAR_CACHE:
	    ClockConfigureClear(dataPtr);
	break;
	case CLOCK_INIT_COMPLETE:
	    {
		/*
		 * Init completed.
		 * Compile clock ensemble (performance purposes).
		 */
		Tcl_Command token = Tcl_FindCommand(interp, "::clock",
		    NULL, TCL_GLOBAL_ONLY);
		if (!token) {
		    return TCL_ERROR;
		}
		int ensFlags = 0;
		if (Tcl_GetEnsembleFlags(interp, token, &ensFlags) != TCL_OK) {
		    return TCL_ERROR;
		}
		ensFlags |= ENSEMBLE_COMPILE;
		if (Tcl_SetEnsembleFlags(interp, token, ensFlags) != TCL_OK) {
		    return TCL_ERROR;
		}
	    }
	break;
	}
    }

    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * ClockGetTZData --
 *
 *	Retrieves tzdata table for given normalized timezone.
 *
 * Results:
 *	Returns a tcl object with tzdata.
 *
 * Side effects:
 *	The tzdata can be cached in ClockClientData structure.
 *
 *----------------------------------------------------------------------
 */

static inline Tcl_Obj *
ClockGetTZData(
    void *clientData,	/* Opaque pointer to literal pool, etc. */
    Tcl_Interp *interp,		/* Tcl interpreter */
    Tcl_Obj *timezoneObj)	/* Name of the timezone */
{
    ClockClientData *dataPtr = (ClockClientData *)clientData;
    Tcl_Obj *ret, **out = NULL;

    /* if cached (if already setup this one) */
    if ( timezoneObj == dataPtr->lastSetupTimeZone
      || timezoneObj == dataPtr->lastSetupTimeZoneUnnorm
    ) {
	if (dataPtr->lastSetupTZData != NULL) {
	    return dataPtr->lastSetupTZData;
	}
	out = &dataPtr->lastSetupTZData;
    }
    /* differentiate GMT and system zones, because used often */
    /* simple caching, because almost used the tz-data of last timezone
     */
    if (timezoneObj == dataPtr->systemTimeZone) {
	if (dataPtr->systemSetupTZData != NULL) {
	    return dataPtr->systemSetupTZData;
	}
	out = &dataPtr->systemSetupTZData;
    }
    else
    if ( timezoneObj == dataPtr->literals[LIT_GMT]
      || timezoneObj == dataPtr->gmtSetupTimeZoneUnnorm
    ) {
	if (dataPtr->gmtSetupTZData != NULL) {
	    return dataPtr->gmtSetupTZData;
	}
	out = &dataPtr->gmtSetupTZData;
    }
    else
    if ( timezoneObj == dataPtr->prevSetupTimeZone
      || timezoneObj == dataPtr->prevSetupTimeZoneUnnorm
    ) {
	if (dataPtr->prevSetupTZData != NULL) {
	    return dataPtr->prevSetupTZData;
	}
	out = &dataPtr->prevSetupTZData;
    }

    ret = Tcl_ObjGetVar2(interp, dataPtr->literals[LIT_TZDATA],
	timezoneObj, TCL_LEAVE_ERR_MSG);

    /* cache using corresponding slot and as last used */
    if (out != NULL) {
	TclSetObjRef(*out, ret);
    }
    else
    if (dataPtr->lastSetupTimeZone != timezoneObj) {
	SavePrevTimezoneObj(dataPtr);
	TclSetObjRef(dataPtr->lastSetupTimeZone, timezoneObj);
	TclUnsetObjRef(dataPtr->lastSetupTimeZoneUnnorm);
	TclSetObjRef(dataPtr->lastSetupTZData, ret);
    }
    return ret;
}

/*
 *----------------------------------------------------------------------
 *
 * ClockGetSystemTimeZone --
 *
 *	Returns system (current) timezone.
 *
 *	If system zone not yet cached, it executes ::tcl::clock::GetSystemTimeZone
 *	in given interpreter and caches its result.
 *
 * Results:
 *	Returns normalized timezone object.
 *
 *----------------------------------------------------------------------
 */

static Tcl_Obj *
ClockGetSystemTimeZone(
    void *clientData,	/* Opaque pointer to literal pool, etc. */
    Tcl_Interp *interp)		/* Tcl interpreter */
{
    ClockClientData *dataPtr = (ClockClientData *)clientData;

    /* if known (cached and same epoch) - return now */
    if (dataPtr->systemTimeZone != NULL
	    && dataPtr->lastTZEpoch == TzsetIfNecessary()) {
	return dataPtr->systemTimeZone;
    }

    TclUnsetObjRef(dataPtr->systemTimeZone);
    TclUnsetObjRef(dataPtr->systemSetupTZData);

    if (Tcl_EvalObjv(interp, 1, &dataPtr->literals[LIT_GETSYSTEMTIMEZONE], 0) != TCL_OK) {
	return NULL;
    }
    if (dataPtr->systemTimeZone == NULL) {
	TclSetObjRef(dataPtr->systemTimeZone, Tcl_GetObjResult(interp));
    }
    Tcl_ResetResult(interp);
    return dataPtr->systemTimeZone;
}

/*
 *----------------------------------------------------------------------
 *
 * ClockSetupTimeZone --
 *
 *	Sets up the timezone. Loads tzdata, etc.
 *
 * Results:
 *	Returns normalized timezone object.
 *
 *----------------------------------------------------------------------
 */

Tcl_Obj *
ClockSetupTimeZone(
    void *clientData,	/* Opaque pointer to literal pool, etc. */
    Tcl_Interp *interp,		/* Tcl interpreter */
    Tcl_Obj *timezoneObj)
{
    ClockClientData *dataPtr = (ClockClientData *)clientData;
    int loaded;
    Tcl_Obj *callargs[2];

    /* if cached (if already setup this one) */
    if ( timezoneObj == dataPtr->literals[LIT_GMT]
      && dataPtr->gmtSetupTZData != NULL
    ) {
	return timezoneObj;
    }
    if ( ( timezoneObj == dataPtr->lastSetupTimeZone
	|| timezoneObj == dataPtr->lastSetupTimeZoneUnnorm
      ) && dataPtr->lastSetupTimeZone != NULL
    ) {
	return dataPtr->lastSetupTimeZone;
    }
    if ( ( timezoneObj == dataPtr->prevSetupTimeZone
	|| timezoneObj == dataPtr->prevSetupTimeZoneUnnorm
      ) && dataPtr->prevSetupTimeZone != NULL
    ) {
	return dataPtr->prevSetupTimeZone;
    }

    /* differentiate normalized (last, GMT and system) zones, because used often and already set */
    callargs[1] = NormTimezoneObj(dataPtr, timezoneObj, &loaded);
    /* if loaded (setup already called for this TZ) */
    if (loaded) {
	return callargs[1];
    }

    /* before setup just take a look in TZData variable */
    if (Tcl_ObjGetVar2(interp, dataPtr->literals[LIT_TZDATA], timezoneObj, 0)) {
    	/* put it to last slot and return normalized */
    	TimezoneLoaded(dataPtr, callargs[1], timezoneObj);
	return callargs[1];
    }
    /* setup now */
    callargs[0] = dataPtr->literals[LIT_SETUPTIMEZONE];
    if (Tcl_EvalObjv(interp, 2, callargs, 0) == TCL_OK) {
	/* save unnormalized last used */
	TclSetObjRef(dataPtr->lastSetupTimeZoneUnnorm, timezoneObj);
	return callargs[1];
    }
    return NULL;
}

/*
 *----------------------------------------------------------------------
 *
 * ClockFormatNumericTimeZone --
 *
 *	Formats a time zone as +hhmmss
 *
 * Parameters:
 *	z - Time zone in seconds east of Greenwich
 *
 * Results:
 *	Returns the time zone object (formatted in a numeric form)
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

Tcl_Obj *
ClockFormatNumericTimeZone(int z) {
    char buf[12+1], *p;

    if ( z < 0 ) {
	z = -z;
	*buf = '-';
    } else {
	*buf = '+';
    }
    TclItoAw(buf+1, z / 3600, '0', 2);   z %= 3600;
    p = TclItoAw(buf+3, z / 60, '0', 2); z %= 60;
    if (z != 0) {
	p = TclItoAw(buf+5, z, '0', 2);
    }
    return Tcl_NewStringObj(buf, p - buf);
}

/*
 *----------------------------------------------------------------------
 *
 * ClockConvertlocaltoutcObjCmd --
 *
 *	Tcl command that converts a UTC time to a local time by whatever means
 *	is available.
 *
 * Usage:
 *	::tcl::clock::ConvertUTCToLocal dictionary timezone changeover
 *
 * Parameters:
 *	dict - Dictionary containing a 'localSeconds' entry.
 *	timezone - Time zone
 *	changeover - Julian Day of the adoption of the Gregorian calendar.
 *
 * Results:
 *	Returns a standard Tcl result.
 *
 * Side effects:
 *	On success, sets the interpreter result to the given dictionary

    Tcl_Obj *secondsObj;
    Tcl_Obj *dict;
    int changeover;
    TclDateFields fields;
    int created = 0;
    int status;

    fields.tzName = NULL;
    /*
     * Check params and convert time.
     */

    if (objc != 4) {
	Tcl_WrongNumArgs(interp, 1, objv, "dict timezone changeover");
	return TCL_ERROR;
    }
    dict = objv[1];
    if (Tcl_DictObjGet(interp, dict, data->literals[LIT_LOCALSECONDS],
	    &secondsObj)!= TCL_OK) {
	return TCL_ERROR;
    }
    if (secondsObj == NULL) {
	Tcl_SetObjResult(interp, Tcl_NewStringObj("key \"localseconds\" not "
		"found in dictionary", -1));
	return TCL_ERROR;
    }
    if ((TclGetWideIntFromObj(interp, secondsObj,
	    &fields.localSeconds) != TCL_OK)
	|| (TclGetIntFromObj(interp, objv[3], &changeover) != TCL_OK)
	|| ConvertLocalToUTC(clientData, interp, &fields, objv[2], changeover)) {
	return TCL_ERROR;
    }

    /*
     * Copy-on-write; set the 'seconds' field in the dictionary and place the
     * modified dictionary in the interpreter result.
     */

 *
 * ClockGetdatefieldsObjCmd --
 *
 *	Tcl command that determines the values that [clock format] will use in
 *	formatting a date, and populates a dictionary with them.
 *
 * Usage:
 *	::tcl::clock::GetDateFields seconds timezone changeover
 *
 * Parameters:
 *	seconds - Time expressed in seconds from the Posix epoch.
 *	timezone - Time zone in which time is to be expressed.

 *	changeover - Julian Day Number at which the current locale adopted
 *		     the Gregorian calendar
 *
 * Results:
 *	Returns a dictonary populated with the fields:
 *		seconds - Seconds from the Posix epoch
 *		localSeconds - Nominal seconds from the Posix epoch in the

{
    TclDateFields fields;
    Tcl_Obj *dict;
    ClockClientData *data = (ClockClientData *)clientData;
    Tcl_Obj *const *lit = data->literals;
    int changeover;

    fields.tzName = NULL;

    /*
     * Check params.
     */

    if (objc != 4) {
	Tcl_WrongNumArgs(interp, 1, objv, "seconds timezone changeover");
	return TCL_ERROR;
    }
    if (TclGetWideIntFromObj(interp, objv[1], &fields.seconds) != TCL_OK
	    || TclGetIntFromObj(interp, objv[3], &changeover) != TCL_OK) {
	return TCL_ERROR;
    }

    /*
     * fields.seconds could be an unsigned number that overflowed. Make sure
     * that it isn't.
     */

    if (TclHasInternalRep(objv[1], &tclBignumType)) {
	Tcl_SetObjResult(interp, lit[LIT_INTEGER_VALUE_TOO_LARGE]);
	return TCL_ERROR;
    }

    /* Extract fields */



    if (ClockGetDateFields(clientData, interp, &fields, objv[2],
	  changeover) != TCL_OK) {
	return TCL_ERROR;
    }





    /* Make dict of fields */












    dict = Tcl_NewDictObj();
    Tcl_DictObjPut(NULL, dict, lit[LIT_LOCALSECONDS],
	    Tcl_NewWideIntObj(fields.localSeconds));
    Tcl_DictObjPut(NULL, dict, lit[LIT_SECONDS],
	    Tcl_NewWideIntObj(fields.seconds));
    Tcl_DictObjPut(NULL, dict, lit[LIT_TZNAME], fields.tzName);

	    Tcl_NewWideIntObj(fields.iso8601Year));
    Tcl_DictObjPut(NULL, dict, lit[LIT_ISO8601WEEK],
	    Tcl_NewWideIntObj(fields.iso8601Week));
    Tcl_DictObjPut(NULL, dict, lit[LIT_DAYOFWEEK],
	    Tcl_NewWideIntObj(fields.dayOfWeek));
    Tcl_SetObjResult(interp, dict);

    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * ClockGetDateFields --
 *
 *	Converts given UTC time (seconds in a TclDateFields structure)
 *	to local time and determines the values that clock routines will
 *	use in scanning or formatting a date.
 *
 * Results:
 *	Date-time values are stored in structure "fields".
 *	Returns a standard Tcl result.
 *
 *----------------------------------------------------------------------
 */

int
ClockGetDateFields(
    void *clientData,	/* Client data of the interpreter */
    Tcl_Interp *interp,		/* Tcl interpreter */
    TclDateFields *fields,	/* Pointer to result fields, where
				 * fields->seconds contains date to extract */
    Tcl_Obj *timezoneObj,	/* Time zone object or NULL for gmt */
    int changeover)		/* Julian Day Number */
{
    /*
     * Convert UTC time to local.
     */

    if (ConvertUTCToLocal(clientData, interp, fields, timezoneObj,
	    changeover) != TCL_OK) {
	return TCL_ERROR;
    }

    /*
     * Extract Julian day and seconds of the day.
     */

    ClockExtractJDAndSODFromSeconds(fields->julianDay, fields->secondOfDay,
	fields->localSeconds);

    /*
     * Convert to Julian or Gregorian calendar.
     */

    GetGregorianEraYearDay(fields, changeover);
    GetMonthDay(fields);
    GetYearWeekDay(fields, changeover);

    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * ClockGetjuliandayfromerayearmonthdayObjCmd --

    Tcl_Obj *dict;
    ClockClientData *data = (ClockClientData *)clientData;
    Tcl_Obj *const *lit = data->literals;
    int changeover;
    int copied = 0;
    int status;
    int isBce = 0;

    fields.tzName = NULL;

    /*
     * Check params.
     */

    if (objc != 3) {
	Tcl_WrongNumArgs(interp, 1, objv, "dict changeover");

    ClockClientData *data = (ClockClientData *)clientData;
    Tcl_Obj *const *lit = data->literals;
    int changeover;
    int copied = 0;
    int status;
    int isBce = 0;

    fields.tzName = NULL;

    /*
     * Check params.
     */

    if (objc != 3) {
	Tcl_WrongNumArgs(interp, 1, objv, "dict changeover");
	return TCL_ERROR;

 *	in the interpreter result on failure.
 *
 *----------------------------------------------------------------------
 */

static int
ConvertLocalToUTC(
    void *clientData,	/* Client data of the interpreter */
    Tcl_Interp *interp,		/* Tcl interpreter */
    TclDateFields *fields,	/* Fields of the time */
    Tcl_Obj *timezoneObj,	/* Time zone */
    int changeover)		/* Julian Day of the Gregorian transition */
{
    ClockClientData *dataPtr = (ClockClientData *)clientData;
    Tcl_Obj *tzdata;		/* Time zone data */
    Tcl_Size rowc;			/* Number of rows in tzdata */
    Tcl_Obj **rowv;		/* Pointers to the rows */
    Tcl_WideInt seconds;
    ClockLastTZOffs * ltzoc = NULL;

    /* fast phase-out for shared GMT-object (don't need to convert UTC 2 UTC) */
    if (timezoneObj == dataPtr->literals[LIT_GMT]) {
	fields->seconds = fields->localSeconds;
	fields->tzOffset = 0;
	return TCL_OK;
    }

    /*
     * Check cacheable conversion could be used
     * (last-period UTC2Local cache within the same TZ and seconds)
     */
    for (rowc = 0; rowc < 2; rowc++) {
	ltzoc = &dataPtr->lastTZOffsCache[rowc];
	if (timezoneObj != ltzoc->timezoneObj || changeover != ltzoc->changeover) {
	    ltzoc = NULL;
	    continue;
	}
	seconds = fields->localSeconds - ltzoc->tzOffset;
	if ( seconds >= ltzoc->rangesVal[0]
	  && seconds <  ltzoc->rangesVal[1]
	) {
	    /* the same time zone and offset (UTC time inside the last minute) */
	    fields->tzOffset = ltzoc->tzOffset;
	    fields->seconds = seconds;
	    return TCL_OK;
	}
	/* in the DST-hole (because of the check above) - correct localSeconds */
	if (fields->localSeconds == ltzoc->localSeconds) {
	    /* the same time zone and offset (but we'll shift local-time) */
	    fields->tzOffset = ltzoc->tzOffset;
	    fields->seconds = seconds;
	    goto dstHole;
	}
    }

    /*
     * Unpack the tz data.
     */

    tzdata = ClockGetTZData(clientData, interp, timezoneObj);
    if (tzdata == NULL) {
	return TCL_ERROR;
    }

    if (TclListObjGetElements(interp, tzdata, &rowc, &rowv) != TCL_OK) {
	return TCL_ERROR;
    }

    /*
     * Special case: If the time zone is :localtime, the tzdata will be empty.
     * Use 'mktime' to convert the time to local
     */

    if (rowc == 0) {

	if (ConvertLocalToUTCUsingC(interp, fields, changeover) != TCL_OK) {
	    return TCL_ERROR;
	};

	/* we cannot cache (ranges unknown yet) - todo: check later the DST-hole here */
	return TCL_OK;

    } else {
	Tcl_WideInt rangesVal[2];

	if (ConvertLocalToUTCUsingTable(interp, fields, rowc, rowv,
		rangesVal) != TCL_OK) {
	    return TCL_ERROR;
	};

	seconds = fields->seconds;

	/* Cache the last conversion */
	if (ltzoc != NULL) { /* slot was found above */
	    /* timezoneObj and changeover are the same */
	    TclSetObjRef(ltzoc->tzName, fields->tzName); /* may be NULL */
	} else {
	    /* no TZ in cache - just move second slot down and use the first one */
	    ltzoc = &dataPtr->lastTZOffsCache[0];
	    TclUnsetObjRef(dataPtr->lastTZOffsCache[1].timezoneObj);
	    TclUnsetObjRef(dataPtr->lastTZOffsCache[1].tzName);
	    memcpy(&dataPtr->lastTZOffsCache[1], ltzoc, sizeof(*ltzoc));
	    TclInitObjRef(ltzoc->timezoneObj, timezoneObj);
	    ltzoc->changeover = changeover;
	    TclInitObjRef(ltzoc->tzName, fields->tzName); /* may be NULL */
	}
	ltzoc->localSeconds = fields->localSeconds;
	ltzoc->rangesVal[0] = rangesVal[0];
	ltzoc->rangesVal[1] = rangesVal[1];
	ltzoc->tzOffset = fields->tzOffset;
    }


    /* check DST-hole: if retrieved seconds is out of range */
    if ( ltzoc->rangesVal[0] > seconds || seconds >= ltzoc->rangesVal[1] ) {
    dstHole:
	#if 0
	printf("given local-time is outside the time-zone (in DST-hole): "
		"%d - offs %d => %d <= %d < %d\n",
		(int)fields->localSeconds, fields->tzOffset,
		(int)ltzoc->rangesVal[0], (int)seconds, (int)ltzoc->rangesVal[1]);
	#endif
	/* because we don't know real TZ (we're outsize), just invalidate local
	 * time (which could be verified in ClockValidDate later) */
	fields->localSeconds = TCL_INV_SECONDS; /* not valid seconds */
    }
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * ConvertLocalToUTCUsingTable --
 *

 *----------------------------------------------------------------------
 */

static int
ConvertLocalToUTCUsingTable(
    Tcl_Interp *interp,		/* Tcl interpreter */
    TclDateFields *fields,	/* Time to convert, with 'seconds' filled in */
    int rowc,			/* Number of points at which time changes */
    Tcl_Obj *const rowv[],	/* Points at which time changes */
    Tcl_WideInt *rangesVal)	/* Return bounds for time period */
{
    Tcl_Obj *row;
    Tcl_Size cellc;
    Tcl_Obj **cellv;
    struct {
	Tcl_Obj *tzName;
	int tzOffset;
    } have[8];
    int nHave = 0;
    Tcl_Size i;


    /*
     * Perform an initial lookup assuming that local == UTC, and locate the
     * last time conversion prior to that time. Get the offset from that row,
     * and look up again. Continue until we find an offset that we found
     * before. This definition, rather than "the same offset" ensures that we
     * don't enter an endless loop, as would otherwise happen when trying to
     * convert a non-existent time such as 02:30 during the US Spring Daylight
     * Saving Time transition.
     */


    fields->tzOffset = 0;
    fields->seconds = fields->localSeconds;
    while (1) {
	row = LookupLastTransition(interp, fields->seconds, rowc, rowv,
		    rangesVal);
	if ((row == NULL)
		|| TclListObjGetElements(interp, row, &cellc,
		    &cellv) != TCL_OK
		|| TclGetIntFromObj(interp, cellv[1],
		    &fields->tzOffset) != TCL_OK) {
	    return TCL_ERROR;
	}

	for (i = 0; i < nHave; ++i) {
	    if (have[i].tzOffset == fields->tzOffset) {
		goto found;

	    }
	}

	if (nHave == 8) {
	    Tcl_Panic("loop in ConvertLocalToUTCUsingTable");
	}
	have[nHave].tzName = cellv[3];
	have[nHave++].tzOffset = fields->tzOffset;

	fields->seconds = fields->localSeconds - fields->tzOffset;
    }

  found:
    fields->tzOffset = have[i].tzOffset;
    fields->seconds = fields->localSeconds - fields->tzOffset;
    TclSetObjRef(fields->tzName, have[i].tzName);

    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * ConvertLocalToUTCUsingC --

    Tcl_Interp *interp,		/* Tcl interpreter */
    TclDateFields *fields,	/* Time to convert, with 'seconds' filled in */
    int changeover)		/* Julian Day of the Gregorian transition */
{
    struct tm timeVal;
    int localErrno;
    int secondOfDay;


    /*
     * Convert the given time to a date.
     */


    ClockExtractJDAndSODFromSeconds(fields->julianDay, secondOfDay,



	fields->localSeconds);

    GetGregorianEraYearDay(fields, changeover);
    GetMonthDay(fields);

    /*
     * Convert the date/time to a 'struct tm'.
     */

 *
 * Side effects:
 *	Populates the 'tzName' and 'tzOffset' fields.
 *
 *----------------------------------------------------------------------
 */

int
ConvertUTCToLocal(
    void *clientData,	/* Client data of the interpreter */
    Tcl_Interp *interp,		/* Tcl interpreter */
    TclDateFields *fields,	/* Fields of the time */
    Tcl_Obj *timezoneObj,	/* Time zone */
    int changeover)		/* Julian Day of the Gregorian transition */
{
    ClockClientData *dataPtr = (ClockClientData *)clientData;
    Tcl_Obj *tzdata;		/* Time zone data */
    Tcl_Size rowc;			/* Number of rows in tzdata */
    Tcl_Obj **rowv;		/* Pointers to the rows */
    ClockLastTZOffs * ltzoc = NULL;

    /* fast phase-out for shared GMT-object (don't need to convert UTC 2 UTC) */
    if (timezoneObj == dataPtr->literals[LIT_GMT]) {
	fields->localSeconds = fields->seconds;
	fields->tzOffset = 0;
	if (dataPtr->gmtTZName == NULL) {
	    Tcl_Obj *tzName;
	    tzdata = ClockGetTZData(clientData, interp, timezoneObj);
	    if ( TclListObjGetElements(interp, tzdata, &rowc, &rowv) != TCL_OK
	      || Tcl_ListObjIndex(interp, rowv[0], 3, &tzName) != TCL_OK) {
		return TCL_ERROR;
	    }
	    TclSetObjRef(dataPtr->gmtTZName, tzName);
	}
	TclSetObjRef(fields->tzName, dataPtr->gmtTZName);
	return TCL_OK;
    }

    /*
     * Check cacheable conversion could be used
     * (last-period UTC2Local cache within the same TZ and seconds)
     */
    for (rowc = 0; rowc < 2; rowc++) {
	ltzoc = &dataPtr->lastTZOffsCache[rowc];
	if (timezoneObj != ltzoc->timezoneObj || changeover != ltzoc->changeover) {
	    ltzoc = NULL;
	    continue;
	}
	if ( fields->seconds >= ltzoc->rangesVal[0]
	  && fields->seconds <  ltzoc->rangesVal[1]
	) {
	    /* the same time zone and offset (UTC time inside the last minute) */
	    fields->tzOffset = ltzoc->tzOffset;
	    fields->localSeconds = fields->seconds + fields->tzOffset;
	    TclSetObjRef(fields->tzName, ltzoc->tzName);
	    return TCL_OK;
	}
    }

    /*
     * Unpack the tz data.
     */

    tzdata = ClockGetTZData(clientData, interp, timezoneObj);
    if (tzdata == NULL) {
	return TCL_ERROR;
    }

    if (TclListObjGetElements(interp, tzdata, &rowc, &rowv) != TCL_OK) {
	return TCL_ERROR;
    }

    /*
     * Special case: If the time zone is :localtime, the tzdata will be empty.
     * Use 'localtime' to convert the time to local
     */

    if (rowc == 0) {

	if (ConvertUTCToLocalUsingC(interp, fields, changeover) != TCL_OK) {
	    return TCL_ERROR;
	}

	/* signal we need to revalidate TZ epoch next time fields gets used. */
	fields->flags |= CLF_CTZ;

	/* we cannot cache (ranges unknown yet) */
    } else {
	Tcl_WideInt rangesVal[2];

	if (ConvertUTCToLocalUsingTable(interp, fields, rowc, rowv,
		rangesVal) != TCL_OK) {
	    return TCL_ERROR;
	}

	/* converted using table (TZ isn't :localtime) */
	fields->flags &= ~CLF_CTZ;

	/* Cache the last conversion */
	if (ltzoc != NULL) { /* slot was found above */
	    /* timezoneObj and changeover are the same */
	    TclSetObjRef(ltzoc->tzName, fields->tzName);
	} else {
	    /* no TZ in cache - just move second slot down and use the first one */
	    ltzoc = &dataPtr->lastTZOffsCache[0];
	    TclUnsetObjRef(dataPtr->lastTZOffsCache[1].timezoneObj);
	    TclUnsetObjRef(dataPtr->lastTZOffsCache[1].tzName);
	    memcpy(&dataPtr->lastTZOffsCache[1], ltzoc, sizeof(*ltzoc));
	    TclInitObjRef(ltzoc->timezoneObj, timezoneObj);
	    ltzoc->changeover = changeover;
	    TclInitObjRef(ltzoc->tzName, fields->tzName);
	}
	ltzoc->localSeconds = fields->localSeconds;
	ltzoc->rangesVal[0] = rangesVal[0];
	ltzoc->rangesVal[1] = rangesVal[1];
	ltzoc->tzOffset = fields->tzOffset;
    }

    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * ConvertUTCToLocalUsingTable --
 *

static int
ConvertUTCToLocalUsingTable(
    Tcl_Interp *interp,		/* Tcl interpreter */
    TclDateFields *fields,	/* Fields of the date */
    Tcl_Size rowc,			/* Number of rows in the conversion table
				 * (>= 1) */
    Tcl_Obj *const rowv[],	/* Rows of the conversion table */
    Tcl_WideInt *rangesVal)	/* Return bounds for time period */
{
    Tcl_Obj *row;		/* Row containing the current information */
    Tcl_Size cellc;			/* Count of cells in the row (must be 4) */
    Tcl_Obj **cellv;		/* Pointers to the cells */

    /*
     * Look up the nearest transition time.
     */

    row = LookupLastTransition(interp, fields->seconds, rowc, rowv, rangesVal);
    if (row == NULL ||
	    TclListObjGetElements(interp, row, &cellc, &cellv) != TCL_OK ||
	    TclGetIntFromObj(interp, cellv[1], &fields->tzOffset) != TCL_OK) {
	return TCL_ERROR;
    }

    /*
     * Convert the time.
     */

    TclSetObjRef(fields->tzName, cellv[3]);

    fields->localSeconds = fields->seconds + fields->tzOffset;
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *

    Tcl_Interp *interp,		/* Tcl interpreter */
    TclDateFields *fields,	/* Time to convert, with 'seconds' filled in */
    int changeover)		/* Julian Day of the Gregorian transition */
{
    time_t tock;
    struct tm *timeVal;		/* Time after conversion */
    int diff;			/* Time zone diff local-Greenwich */
    char buffer[16], *p;	/* Buffer for time zone name */

    /*
     * Use 'localtime' to determine local year, month, day, time of day.
     */

    tock = (time_t) fields->seconds;
    if ((Tcl_WideInt) tock != fields->seconds) {

    fields->dayOfMonth = timeVal->tm_mday;
    GetJulianDayFromEraYearMonthDay(fields, changeover);

    /*
     * Convert that value to seconds.
     */

    fields->localSeconds = (((fields->julianDay * 24LL
	    + timeVal->tm_hour) * 60 + timeVal->tm_min) * 60
	    + timeVal->tm_sec) - JULIAN_SEC_POSIX_EPOCH;

    /*
     * Determine a time zone offset and name; just use +hhmm for the name.
     */

    diff = (int) (fields->localSeconds - fields->seconds);
    fields->tzOffset = diff;
    if (diff < 0) {
	*buffer = '-';
	diff = -diff;
    } else {
	*buffer = '+';
    }

    TclItoAw(buffer+1, diff / 3600, '0', 2);   diff %= 3600;

    p = TclItoAw(buffer+3, diff / 60, '0', 2); diff %= 60;
    if (diff != 0) {
	p = TclItoAw(buffer+5, diff, '0', 2);
    }
    TclSetObjRef(fields->tzName, Tcl_NewStringObj(buffer, p - buffer));

    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * LookupLastTransition --
 *
 *	Given a UTC time and a tzdata array, looks up the last transition on
 *	or before the given time.
 *
 * Results:
 *	Returns a pointer to the row, or NULL if an error occurs.
 *
 *----------------------------------------------------------------------
 */

Tcl_Obj *
LookupLastTransition(
    Tcl_Interp *interp,		/* Interpreter for error messages */
    Tcl_WideInt tick,		/* Time from the epoch */
    Tcl_Size rowc,			/* Number of rows of tzdata */
    Tcl_Obj *const *rowv,	/* Rows in tzdata */
    Tcl_WideInt *rangesVal)	/* Return bounds for time period */
{
	Tcl_Size l, u;
    Tcl_Obj *compObj;
    Tcl_WideInt compVal, fromVal = LLONG_MIN, toVal = LLONG_MAX;

    /*
     * Examine the first row to make sure we're in bounds.
     */

    if (Tcl_ListObjIndex(interp, rowv[0], 0, &compObj) != TCL_OK
	    || TclGetWideIntFromObj(interp, compObj, &compVal) != TCL_OK) {
	return NULL;
    }

    /*
     * Bizarre case - first row doesn't begin at MIN_WIDE_INT. Return it
     * anyway.
     */

    if (tick < (fromVal = compVal)) {
	if (rangesVal) {
	    rangesVal[0] = fromVal;
	    rangesVal[1] = toVal;
	}
	return rowv[0];
    }

    /*
     * Binary-search to find the transition.
     */

    l = 0;
    u = rowc-1;
    while (l < u) {
	Tcl_Size m = (l + u + 1) / 2;

	if (Tcl_ListObjIndex(interp, rowv[m], 0, &compObj) != TCL_OK ||
		TclGetWideIntFromObj(interp, compObj, &compVal) != TCL_OK) {
	    return NULL;
	}
	if (tick >= compVal) {
	    l = m;
	    fromVal = compVal;
	} else {
	    u = m-1;
	    toVal = compVal;
	}
    }

    if (rangesVal) {
	rangesVal[0] = fromVal;
	rangesVal[1] = toVal;
    }
    return rowv[l];
}

/*
 *----------------------------------------------------------------------
 *
 * GetYearWeekDay --

GetYearWeekDay(
    TclDateFields *fields,	/* Date to convert, must have 'julianDay' */
    int changeover)		/* Julian Day Number of the Gregorian
				 * transition */
{
    TclDateFields temp;
    int dayOfFiscalYear;

    temp.tzName = NULL;

    /*
     * Find the given date, minus three days, plus one year. That date's
     * iso8601 year is an upper bound on the ISO8601 year of the given date.
     */

    temp.julianDay = fields->julianDay - 3;

 *
 * Side effects:
 *	Stores 'julianDay' in the fields.
 *
 *----------------------------------------------------------------------
 */

void
GetJulianDayFromEraYearWeekDay(
    TclDateFields *fields,	/* Date to convert */
    int changeover)		/* Julian Day Number of the Gregorian
				 * transition */
{
    Tcl_WideInt firstMonday;	/* Julian day number of week 1, day 1 in the
				 * given year */
    TclDateFields firstWeek;

    firstWeek.tzName = NULL;

    /*
     * Find January 4 in the ISO8601 year, which will always be in week 1.
     */

    firstWeek.isBce = fields->isBce;
    firstWeek.year = fields->iso8601Year;

 *
 * Side effects:
 *	Stores day number in 'julianDay'
 *
 *----------------------------------------------------------------------
 */

void
GetJulianDayFromEraYearMonthDay(
    TclDateFields *fields,	/* Date to convert */
    int changeover)		/* Gregorian transition date as a Julian Day */
{
    Tcl_WideInt year, ym1, ym1o4, ym1o100, ym1o400;
    int month, mm1, q, r;

		+ ym1o4;
    }
}

/*
 *----------------------------------------------------------------------
 *
 * GetJulianDayFromEraYearDay --
 *
 *	Given era, year, and dayOfYear (in TclDateFields), and the
 *	Gregorian transition date, computes the Julian Day Number.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Stores day number in 'julianDay'
 *
 *----------------------------------------------------------------------
 */


void
GetJulianDayFromEraYearDay(
    TclDateFields *fields,	/* Date to convert */
    int changeover)		/* Gregorian transition date as a Julian Day */
{
    Tcl_WideInt year, ym1;

    /* Get absolute year number from the civil year */
    if (fields->isBce) {
	year = 1 - fields->year;
    } else {
	year = fields->year;
    }

    ym1 = year - 1;

    /* Try the Gregorian calendar first. */
    fields->gregorian = 1;
    fields->julianDay =
	1721425
	+ fields->dayOfYear
	+ ( 365 * ym1 )
	+ ( ym1 / 4 )
	- ( ym1 / 100 )
	+ ( ym1 / 400 );

    /* If the date is before the Gregorian change, use the Julian calendar. */

    if ( fields->julianDay < changeover ) {
	fields->gregorian = 0;
	fields->julianDay =
	    1721423
	    + fields->dayOfYear
	    + ( 365 * ym1 )
	    + ( ym1 / 4 );
    }
}
/*
 *----------------------------------------------------------------------
 *
 * IsGregorianLeapYear --
 *
 *	Tests whether a given year is a leap year, in either Julian or
 *	Gregorian calendar.
 *
 * Results:
 *	Returns 1 for a leap year, 0 otherwise.
 *
 *----------------------------------------------------------------------
 */

int
IsGregorianLeapYear(
    TclDateFields *fields)	/* Date to test */
{
    Tcl_WideInt year = fields->year;

    if (fields->isBce) {
	year = 1 - year;

    case 2:
	if (Tcl_GetIndexFromObj(interp, objv[1], clicksSwitches, "option", 0,
		&index) != TCL_OK) {
	    return TCL_ERROR;
	}
	break;
    default:
	Tcl_WrongNumArgs(interp, 0, objv, "clock clicks ?-switch?");
	return TCL_ERROR;
    }

    switch (index) {
    case CLICKS_MILLIS:
	Tcl_GetTime(&now);
	clicks = now.sec * 1000LL + now.usec / 1000;
	break;
    case CLICKS_NATIVE:
#ifdef TCL_WIDE_CLICKS
	clicks = TclpGetWideClicks();
#else
	clicks = (Tcl_WideInt)TclpGetClicks();
#endif

    int objc,			/* Parameter count */
    Tcl_Obj *const *objv)	/* Parameter values */
{
    Tcl_Time now;
    Tcl_Obj *timeObj;

    if (objc != 1) {
	Tcl_WrongNumArgs(interp, 0, objv, "clock milliseconds");
	return TCL_ERROR;
    }
    Tcl_GetTime(&now);
    TclNewUIntObj(timeObj, (Tcl_WideUInt)
	    now.sec * 1000 + now.usec / 1000);
    Tcl_SetObjResult(interp, timeObj);
    return TCL_OK;

ClockMicrosecondsObjCmd(
    TCL_UNUSED(void *),
    Tcl_Interp *interp,		/* Tcl interpreter */
    int objc,			/* Parameter count */
    Tcl_Obj *const *objv)	/* Parameter values */
{
    if (objc != 1) {
	Tcl_WrongNumArgs(interp, 0, objv, "clock microseconds");
	return TCL_ERROR;
    }
    Tcl_SetObjResult(interp, Tcl_NewWideIntObj(TclpGetMicroseconds()));
    return TCL_OK;
}

static inline void
ClockInitFmtScnArgs(
    void *clientData,
    Tcl_Interp *interp,
    ClockFmtScnCmdArgs *opts)
{
    memset(opts, 0, sizeof(*opts));
    opts->clientData = clientData;
    opts->interp = interp;
}

/*
 *-----------------------------------------------------------------------------
 *
 * ClockParseFmtScnArgs --
 *
 *	Parses the arguments for sub-commands "scan", "format" and "add".
 *
 *	Note:	common options table used here, because for the options often used
 *		the same literals (objects), so it avoids permanent "recompiling" of
 *		option object representation to indexType with another table.
 *
 * Results:
 *	Returns a standard Tcl result, and stores parsed options
 *	(format, the locale, timezone and base) in structure "opts".
 *




 *-----------------------------------------------------------------------------
 */

#define CLC_FMT_ARGS	(0)





#define CLC_SCN_ARGS	(1 << 0)
#define CLC_ADD_ARGS	(1 << 1)

static int
ClockParseFmtScnArgs(
    ClockFmtScnCmdArgs *opts,	/* Result vector: format, locale, timezone... */
    TclDateFields      *date,	/* Extracted date-time corresponding base
				 * (by scan or add) resp. clockval (by format) */
    int objc,			/* Parameter count */
    Tcl_Obj *const objv[],	/* Parameter vector */
    int		flags,		/* Flags, differentiates between format, scan, add */
    const char *syntax		/* Syntax of the current command */
) {
    Tcl_Interp	    *interp =  opts->interp;
    ClockClientData *dataPtr = (ClockClientData *)opts->clientData;





    int gmtFlag = 0;
    static const char *const options[] = {
	"-base", "-format", "-gmt", "-locale", "-timezone", "-validate", NULL
    };
    enum optionInd {
	CLC_ARGS_BASE, CLC_ARGS_FORMAT, CLC_ARGS_GMT, CLC_ARGS_LOCALE,
	CLC_ARGS_TIMEZONE, CLC_ARGS_VALIDATE
    };
    int optionIndex;		/* Index of an option. */
    int saw = 0;		/* Flag == 1 if option was seen already. */

    int i;
    Tcl_WideInt baseVal;	/* Base time, expressed in seconds from the Epoch */




    if ( flags & (CLC_SCN_ARGS) ) {


    	/* default flags (from configure) */
    	opts->flags |= dataPtr->defFlags & (CLF_VALIDATE);
    } else {
    	/* clock value (as current base) */
	opts->baseObj = objv[1];
	saw |= (1 << CLC_ARGS_BASE);
    }

    /*
     * Extract values for the keywords.
     */




    for (i = 2; i < objc; i+=2) {
	/* bypass integers (offsets) by "clock add" */
	if (flags & CLC_ADD_ARGS) {
	    Tcl_WideInt num;
	    if (TclGetWideIntFromObj(NULL, objv[i], &num) == TCL_OK) {
		continue;
	    }
	}
	/* get option */
	if (Tcl_GetIndexFromObj(interp, objv[i], options,
	    "option", 0, &optionIndex) != TCL_OK) {
	    goto badOptionMsg;
	}
	/* if already specified */
	if (saw & (1 << optionIndex)) {
	    if ( !(flags & CLC_SCN_ARGS)
	       && optionIndex == CLC_ARGS_BASE) {
		goto badOptionMsg;
	    }
	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
		"bad option \"%s\": doubly present",
		TclGetString(objv[i]))

	    );
	    goto badOption;
	}
	switch (optionIndex) {
	case CLC_ARGS_FORMAT:
	    if (flags & CLC_ADD_ARGS) {
		goto badOptionMsg;
	    }
	    opts->formatObj = objv[i+1];
	    break;
	case CLC_ARGS_GMT:
	    if (Tcl_GetBooleanFromObj(interp, objv[i+1], &gmtFlag) != TCL_OK){
		return TCL_ERROR;
	    }
	    break;
	case CLC_ARGS_LOCALE:
	    opts->localeObj = objv[i+1];
	    break;
	case CLC_ARGS_TIMEZONE:
	    opts->timezoneObj = objv[i+1];
	    break;
	case CLC_ARGS_BASE:
	    opts->baseObj = objv[i+1];
	    break;
	case CLC_ARGS_VALIDATE:
	    if ( !(flags & CLC_SCN_ARGS) ) {
		goto badOptionMsg;
	    } else {
		int val;
		if (Tcl_GetBooleanFromObj(interp, objv[i+1], &val) != TCL_OK) {
		    return TCL_ERROR;
		}
		if (val) {
		    opts->flags |= CLF_VALIDATE;
		} else {
		    opts->flags &= ~CLF_VALIDATE;
		}
	    }
	    break;
	}
	saw |= (1 << optionIndex);
    }

    /*
     * Check options.
     */




    if ((saw & (1 << CLC_ARGS_GMT))
	    && (saw & (1 << CLC_ARGS_TIMEZONE))) {
	Tcl_SetObjResult(interp, Tcl_NewStringObj("cannot use -gmt and -timezone in same call", -1));
	Tcl_SetErrorCode(interp, "CLOCK", "gmtWithTimezone", (char *)NULL);
	return TCL_ERROR;
    }
    if (gmtFlag) {
	opts->timezoneObj = dataPtr->literals[LIT_GMT];
    }
    else
    /* If time zone not specified use system time zone */
    if ( opts->timezoneObj == NULL
      || TclGetString(opts->timezoneObj) == NULL
      || opts->timezoneObj->length == 0
    ) {
	opts->timezoneObj = ClockGetSystemTimeZone(opts->clientData, interp);
	if (opts->timezoneObj == NULL) {
	    return TCL_ERROR;
	}
    }

    /* Setup timezone (normalize object if needed and load TZ on demand) */

    opts->timezoneObj = ClockSetupTimeZone(opts->clientData, interp, opts->timezoneObj);
    if (opts->timezoneObj == NULL) {
	return TCL_ERROR;
    }

    /* Base (by scan or add) or clock value (by format) */

    if (opts->baseObj != NULL) {
	Tcl_Obj *baseObj = opts->baseObj;
	/* bypass integer recognition if looks like option "-now" */
	if (
	    (baseObj->length == 4 && baseObj->bytes && *(baseObj->bytes+1) == 'n') ||
	    TclGetWideIntFromObj(NULL, baseObj, &baseVal) != TCL_OK
	) {

	    /* we accept "-now" as current date-time */
	    static const char *const nowOpts[] = {
		"-now", NULL
	    };
	    int idx;
	    if (Tcl_GetIndexFromObj(NULL, baseObj, nowOpts, "seconds or -now",
		    TCL_EXACT, &idx) == TCL_OK
	    ) {
		goto baseNow;
	    }

	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
		    "expected integer but got \"%s\"",
		    Tcl_GetString(baseObj)));
	    Tcl_SetErrorCode(interp, "TCL", "VALUE", "INTEGER", (char *)NULL);
	    i = 1;
	    goto badOption;
	}
	/*
	 * Seconds could be an unsigned number that overflowed. Make sure
	 * that it isn't. Additionally it may be too complex to calculate
	 * julianday etc (forwards/backwards) by too large/small values, thus
	 * just let accept a bit shorter values to avoid overflow.
	 * Note the year is currently an integer, thus avoid to overflow it also.
	 */

	if ( baseObj->typePtr == &tclBignumType
	  || baseVal < TCL_MIN_SECONDS || baseVal > TCL_MAX_SECONDS
	) {
	    Tcl_SetObjResult(interp, dataPtr->literals[LIT_INTEGER_VALUE_TOO_LARGE]);
	    return TCL_ERROR;
	}

    } else {

baseNow:
	{
	    Tcl_Time now;
	    Tcl_GetTime(&now);
	    baseVal = (Tcl_WideInt) now.sec;
	}
    }

    /*
     * Extract year, month and day from the base time for the parser to use as
     * defaults
     */

    /* check base fields already cached (by TZ, last-second cache) */
    if ( dataPtr->lastBase.timezoneObj == opts->timezoneObj
      && dataPtr->lastBase.date.seconds == baseVal
      && (!(dataPtr->lastBase.date.flags & CLF_CTZ)
	     || dataPtr->lastTZEpoch == TzsetIfNecessary())
    ) {
	memcpy(date, &dataPtr->lastBase.date, ClockCacheableDateFieldsSize);
    } else {
	/* extact fields from base */
	date->seconds = baseVal;
	if (ClockGetDateFields(opts->clientData, interp, date, opts->timezoneObj,
	      GREGORIAN_CHANGE_DATE) != TCL_OK) { /* TODO - GREGORIAN_CHANGE_DATE should be locale-dependent */
	    return TCL_ERROR;
	}
	/* cache last base */
	memcpy(&dataPtr->lastBase.date, date, ClockCacheableDateFieldsSize);
	TclSetObjRef(dataPtr->lastBase.timezoneObj, opts->timezoneObj);
    }

    return TCL_OK;

badOptionMsg:

    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
	"bad option \"%s\": must be %s",
	TclGetString(objv[i]), syntax)
    );

badOption:

    Tcl_SetErrorCode(interp, "CLOCK", "badOption",
	    (i < objc) ? Tcl_GetString(objv[i]) : (char *)NULL, (char *)NULL);

    return TCL_ERROR;
}

/*----------------------------------------------------------------------
 *
 * ClockFormatObjCmd -- , clock format --
 *
 *	This function is invoked to process the Tcl "clock format" command.
 *
 *	Formats a count of seconds since the Posix Epoch as a time of day.
 *
 *	The 'clock format' command formats times of day for output.  Refer
 *	to the user documentation to see what it does.
 *
 * Results:
 *	Returns a standard Tcl result.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

int
ClockFormatObjCmd(
    void *clientData,	/* Client data containing literal pool */
    Tcl_Interp *interp,		/* Tcl interpreter */
    int objc,			/* Parameter count */
    Tcl_Obj *const objv[])	/* Parameter values */
{
    ClockClientData *dataPtr = (ClockClientData *)clientData;

    static const char *syntax = "clock format clockval|-now "
	"?-format string? "
	"?-gmt boolean? "
	"?-locale LOCALE? ?-timezone ZONE?";
    int ret;
    ClockFmtScnCmdArgs opts;	/* Format, locale, timezone and base */
    DateFormat	    dateFmt;	/* Common structure used for formatting */

    /* even number of arguments */
    if ((objc & 1) == 1) {
	Tcl_WrongNumArgs(interp, 0, objv, syntax);
	Tcl_SetErrorCode(interp, "CLOCK", "wrongNumArgs", (char *)NULL);
	return TCL_ERROR;
    }

    memset(&dateFmt, 0, sizeof(dateFmt));

    /*
     * Extract values for the keywords.
     */

    ClockInitFmtScnArgs(clientData, interp, &opts);
    ret = ClockParseFmtScnArgs(&opts, &dateFmt.date, objc, objv,
	    CLC_FMT_ARGS, "-format, -gmt, -locale, or -timezone");
    if (ret != TCL_OK) {
	goto done;
    }

    /* Default format */
    if (opts.formatObj == NULL) {
	opts.formatObj = dataPtr->literals[LIT__DEFAULT_FORMAT];
    }

    /* Use compiled version of Format - */

    ret = ClockFormat(&dateFmt, &opts);

done:

    TclUnsetObjRef(dateFmt.date.tzName);

    if (ret != TCL_OK) {
	return ret;
    }

    return TCL_OK;
}

/*----------------------------------------------------------------------
 *
 * ClockScanObjCmd -- , clock scan --
 *
 *	This function is invoked to process the Tcl "clock scan" command.
 *
 *	Inputs a count of seconds since the Posix Epoch as a time of day.
 *
 *	The 'clock scan' command scans times of day on input. Refer to the
 *	user documentation to see what it does.
 *
 * Results:
 *	Returns a standard Tcl result.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

int
ClockScanObjCmd(
    void *clientData,	/* Client data containing literal pool */
    Tcl_Interp *interp,		/* Tcl interpreter */
    int objc,			/* Parameter count */
    Tcl_Obj *const objv[])	/* Parameter values */
{
    static const char *syntax = "clock scan string "
	    "?-base seconds? "
	    "?-format string? "
	    "?-gmt boolean? "
	    "?-locale LOCALE? ?-timezone ZONE? ?-validate boolean?";
    int ret;
    ClockFmtScnCmdArgs opts;	/* Format, locale, timezone and base */
    DateInfo	    yy;		/* Common structure used for parsing */
    DateInfo	   *info = &yy;

    /* even number of arguments */
    if ((objc & 1) == 1) {
	Tcl_WrongNumArgs(interp, 0, objv, syntax);
	Tcl_SetErrorCode(interp, "CLOCK", "wrongNumArgs", (char *)NULL);
	return TCL_ERROR;
    }

    ClockInitDateInfo(&yy);

    /*
     * Extract values for the keywords.
     */

    ClockInitFmtScnArgs(clientData, interp, &opts);
    ret = ClockParseFmtScnArgs(&opts, &yy.date, objc, objv,
	    CLC_SCN_ARGS, "-base, -format, -gmt, -locale, -timezone or -validate");
    if (ret != TCL_OK) {
	goto done;
    }

    /* seconds are in localSeconds (relative base date), so reset time here */
    yyHour = yyMinutes = yySeconds = yySecondOfDay = 0; yyMeridian = MER24;

    /* If free scan */
    if (opts.formatObj == NULL) {
	/* Use compiled version of FreeScan - */

	/* [SB] TODO: Perhaps someday we'll localize the legacy code. Right now, it's not localized. */
	if (opts.localeObj != NULL) {
	    Tcl_SetObjResult(interp,
		Tcl_NewStringObj("legacy [clock scan] does not support -locale", -1));
	    Tcl_SetErrorCode(interp, "CLOCK", "flagWithLegacyFormat", (char *)NULL);
	    ret = TCL_ERROR;
	    goto done;
	}
	ret = ClockFreeScan(&yy, objv[1], &opts);
    }
    else {
	/* Use compiled version of Scan - */

	ret = ClockScan(&yy, objv[1], &opts);
    }

    if (ret != TCL_OK) {
	goto done;
    }

    /*
     * If no GMT and not free-scan (where valid stage 1 is done in-between),
     * validate with stage 1 before local time conversion, otherwise it may
     * adjust date/time tokens to valid values
     */
    if ( (opts.flags & CLF_VALIDATE_S1) &&
	 info->flags & (CLF_ASSEMBLE_SECONDS|CLF_LOCALSEC)
    ) {
	ret = ClockValidDate(&yy, &opts, CLF_VALIDATE_S1);
	if (ret != TCL_OK) {
	    goto done;
	}
    }

    /* Convert date info structure into UTC seconds */

    ret = ClockScanCommit(&yy, &opts);
    if (ret != TCL_OK) {
	goto done;
    }

    /* Apply remaining validation rules, if expected */
    if ( (opts.flags & CLF_VALIDATE) ) {
	ret = ClockValidDate(&yy, &opts, opts.flags & CLF_VALIDATE);
	if (ret != TCL_OK) {
	    goto done;
	}
    }

done:

    TclUnsetObjRef(yy.date.tzName);

    if (ret != TCL_OK) {
	return ret;
    }

    Tcl_SetObjResult(interp, Tcl_NewWideIntObj(yy.date.seconds));
    return TCL_OK;
}

/*----------------------------------------------------------------------
 *
 * ClockScanCommit --
 *
 *	Converts date info structure into UTC seconds.
 *
 * Results:
 *	Returns a standard Tcl result.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static int
ClockScanCommit(
    DateInfo  *info,	/* Clock scan info structure */
    ClockFmtScnCmdArgs *opts)	/* Format, locale, timezone and base */
{
    /* If needed assemble julianDay using year, month, etc. */
    if (info->flags & CLF_ASSEMBLE_JULIANDAY) {
	if ((info->flags & CLF_ISO8601WEAK)) {
	    GetJulianDayFromEraYearWeekDay(&yydate, GREGORIAN_CHANGE_DATE);
	}
	else
	if ( !(info->flags & CLF_DAYOFYEAR) /* no day of year */
	   || (info->flags & (CLF_DAYOFMONTH|CLF_MONTH)) /* yymmdd over yyddd */
		== (CLF_DAYOFMONTH|CLF_MONTH)
	) {
	    GetJulianDayFromEraYearMonthDay(&yydate, GREGORIAN_CHANGE_DATE);
	} else {
	    GetJulianDayFromEraYearDay(&yydate, GREGORIAN_CHANGE_DATE);
	}
	info->flags |= CLF_ASSEMBLE_SECONDS;
	info->flags &= ~CLF_ASSEMBLE_JULIANDAY;
    }

    /* some overflow checks */
    if (info->flags & CLF_JULIANDAY) {
	ClockClientData *dataPtr = (ClockClientData *)opts->clientData;
	double curJDN = (double)yydate.julianDay
	    + ((double)yySecondOfDay - SECONDS_PER_DAY/2) / SECONDS_PER_DAY;
	if (curJDN > dataPtr->maxJDN) {
	    Tcl_SetObjResult(opts->interp, Tcl_NewStringObj(
		"requested date too large to represent", -1));
	    Tcl_SetErrorCode(opts->interp, "CLOCK", "dateTooLarge", (char *)NULL);
	    return TCL_ERROR;
	}
    }

    /* Local seconds to UTC (stored in yydate.seconds) */

    if (info->flags & (CLF_ASSEMBLE_SECONDS)) {
	yydate.localSeconds =
	    -210866803200LL
	    + ( SECONDS_PER_DAY * yydate.julianDay )
	    + ( yySecondOfDay % SECONDS_PER_DAY );
    }

    if (info->flags & (CLF_ASSEMBLE_SECONDS|CLF_LOCALSEC)) {
	if (ConvertLocalToUTC(opts->clientData, opts->interp, &yydate,
		opts->timezoneObj, GREGORIAN_CHANGE_DATE) != TCL_OK) {
	    return TCL_ERROR;
	}
    }

    /* Increment UTC seconds with relative time */

    yydate.seconds += yyRelSeconds;

    return TCL_OK;
}

/*----------------------------------------------------------------------
 *
 * ClockValidDate --
 *
 *	Validate date info structure for wrong data (e. g. out of ranges).
 *
 * Results:
 *	Returns a standard Tcl result.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static int
ClockValidDate(
    DateInfo  *info,	/* Clock scan info structure */
    ClockFmtScnCmdArgs *opts,	/* Scan options */
    int stage)			/* Stage to validate (1, 2 or 3 for both) */
{
    const char *errMsg = "", *errCode = "";
    TclDateFields temp;
    int tempCpyFlg = 0;
    ClockClientData *dataPtr = (ClockClientData *)opts->clientData;

    #if 0
    printf("yyMonth %d, yyDay %d, yyDayOfYear %d, yyHour %d, yyMinutes %d, yySeconds %d, "
	   "yySecondOfDay %d, sec %d, daySec %d, tzOffset %d\n",
	  yyMonth, yyDay, yydate.dayOfYear, yyHour, yyMinutes, yySeconds,
	  yySecondOfDay, (int)yydate.localSeconds, (int)(yydate.localSeconds % SECONDS_PER_DAY),
	  yydate.tzOffset);
    #endif

    if (!(stage & CLF_VALIDATE_S1) || !(opts->flags & CLF_VALIDATE_S1)) {
	goto stage_2;
    }
    opts->flags &= ~CLF_VALIDATE_S1; /* stage 1 is done */

    /* first year (used later in hath / daysInPriorMonths) */
    if ((info->flags & (CLF_YEAR|CLF_ISO8601YEAR))) {
	if ((info->flags & CLF_ISO8601YEAR)) {
	    if ( yydate.iso8601Year < dataPtr->validMinYear
	      || yydate.iso8601Year > dataPtr->validMaxYear ) {
		errMsg = "invalid iso year"; errCode = "iso year"; goto error;
	    }
	}
	if (info->flags & CLF_YEAR) {
	    if ( yyYear < dataPtr->validMinYear
	      || yyYear > dataPtr->validMaxYear ) {
		errMsg = "invalid year"; errCode = "year"; goto error;
	    }
	} else if ((info->flags & CLF_ISO8601YEAR)) {
	    yyYear = yydate.iso8601Year; /* used to recognize leap */
	}
	if ((info->flags & (CLF_ISO8601YEAR|CLF_YEAR))
		== (CLF_ISO8601YEAR|CLF_YEAR)) {
	    if (yyYear != yydate.iso8601Year) {
		errMsg = "ambiguous year"; errCode = "year"; goto error;
	    }
	}
    }
    /* and month (used later in hath) */
    if (info->flags & CLF_MONTH) {
	if ( yyMonth < 1 || yyMonth > 12 ) {
	    errMsg = "invalid month"; errCode = "month"; goto error;
	}
    }
    /* day of month */
    if (info->flags & (CLF_DAYOFMONTH|CLF_DAYOFWEEK)) {
	if ( yyDay < 1 || yyDay > 31 ) {
	    errMsg = "invalid day"; errCode = "day"; goto error;
	}
	else
	if ( (info->flags & CLF_MONTH) ) {
	    const int *h = hath[IsGregorianLeapYear(&yydate)];
	    if ( yyDay > h[yyMonth-1] ) {
		errMsg = "invalid day"; goto error;
	    }
	}
    }
    if (info->flags & CLF_DAYOFYEAR) {
	if ( yydate.dayOfYear < 1
	  || yydate.dayOfYear > daysInPriorMonths[IsGregorianLeapYear(&yydate)][12] ) {
	    errMsg = "invalid day of year"; errCode = "day of year"; goto error;
	}
    }

    /* mmdd !~ ddd */
    if ((info->flags & (CLF_DAYOFYEAR|CLF_DAYOFMONTH|CLF_MONTH))
		== (CLF_DAYOFYEAR|CLF_DAYOFMONTH|CLF_MONTH)) {
	if (!tempCpyFlg) {
	    memcpy(&temp, &yydate, sizeof(temp));
	    tempCpyFlg = 1;
	}
	GetJulianDayFromEraYearDay(&temp, GREGORIAN_CHANGE_DATE);
	if (temp.julianDay != yydate.julianDay) {
	    errMsg = "ambiguous day"; errCode = "day"; goto error;
	}
    }

    if (info->flags & CLF_TIME) {
	/* hour */
	if ( yyHour < 0 || yyHour > ((yyMeridian == MER24) ? 23 : 12) ) {
	    errMsg = "invalid time (hour)"; errCode = "hour"; goto error;
	}
	/* minutes */
	if ( yyMinutes < 0 || yyMinutes > 59 ) {
	    errMsg = "invalid time (minutes)"; errCode = "minutes"; goto error;
	}
	/* oldscan could return secondOfDay (parsedTime) -1 by invalid time (ex.: 25:00:00) */
	if ( yySeconds < 0 || yySeconds > 59 || yySecondOfDay <= -1 ) {
	    errMsg = "invalid time"; errCode = "seconds"; goto error;
	}
    }

    if (!(stage & CLF_VALIDATE_S2) || !(opts->flags & CLF_VALIDATE_S2)) {
	return TCL_OK;
    }
    opts->flags &= ~CLF_VALIDATE_S2; /* stage 2 is done */

    /*
     * Further tests expected ready calculated julianDay (inclusive relative),
     * and time-zone conversion (local to UTC time).
     */
  stage_2:

    /* time, regarding the modifications by the time-zone (looks for given time
     * in between DST-time hole, so does not exist in this time-zone) */
    if (info->flags & CLF_TIME) {
	/*
	 * we don't need to do the backwards time-conversion (UTC to local) and
	 * compare results, because the after conversion (local to UTC) we
	 * should have valid localSeconds (was not invalidated to TCL_INV_SECONDS),
	 * so if it was invalidated - invalid time, outside the time-zone (in DST-hole)
	 */
	if ( yydate.localSeconds == TCL_INV_SECONDS ) {
	    errMsg = "invalid time (does not exist in this time-zone)";
	    errCode = "out-of-time"; goto error;
	}
    }

    /* day of week */
    if (info->flags & CLF_DAYOFWEEK) {
	if (!tempCpyFlg) {
	    memcpy(&temp, &yydate, sizeof(temp));
	    tempCpyFlg = 1;
	}
	GetYearWeekDay(&temp, GREGORIAN_CHANGE_DATE);
	if (temp.dayOfWeek != yyDayOfWeek) {
	    errMsg = "invalid day of week"; errCode = "day of week"; goto error;
	}
    }

    return TCL_OK;

  error:
    Tcl_SetObjResult(opts->interp,
	Tcl_ObjPrintf("unable to convert input string: %s", errMsg));
    Tcl_SetErrorCode(opts->interp, "CLOCK", "invInpStr", errCode, (char *)NULL);
    return TCL_ERROR;
}

/*----------------------------------------------------------------------
 *
 * ClockFreeScan --
 *
 *	Used by ClockScanObjCmd for free scanning without format.
 *
 * Results:
 *	Returns a standard Tcl result.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

int
ClockFreeScan(
    DateInfo	       *info,	/* Date fields used for parsing & converting
				 * simultaneously a yy-parse structure of the
				 * TclClockFreeScan */
    Tcl_Obj *strObj,		/* String containing the time to scan */
    ClockFmtScnCmdArgs *opts)	/* Command options */
{
    Tcl_Interp	    *interp =  opts->interp;
    ClockClientData *dataPtr = (ClockClientData *)opts->clientData;

    int ret = TCL_ERROR;

    /*
     * Parse the date. The parser will fill a structure "info" with date,
     * time, time zone, relative month/day/seconds, relative weekday, ordinal
     * month.
     * Notice that many yy-defines point to values in the "info" or "date"
     * structure, e. g. yySecondOfDay -> info->date.secondOfDay or
     *			yyMonth -> info->date.month (same as yydate.month)
     */
    yyInput = Tcl_GetString(strObj);

    if (TclClockFreeScan(interp, info) != TCL_OK) {
	Tcl_Obj *msg;
	TclNewObj(msg);
	Tcl_AppendPrintfToObj(msg, "unable to convert date-time string \"%s\": %s",
	    Tcl_GetString(strObj), TclGetString(Tcl_GetObjResult(interp)));
	Tcl_SetObjResult(interp, msg);
	goto done;
    }

    /*
     * If the caller supplied a date in the string, update the date with
     * the value. If the caller didn't specify a time with the date, default to
     * midnight.
     */

    if (info->flags & CLF_YEAR) {
	if (yyYear < 100) {
	    if (yyYear >= dataPtr->yearOfCenturySwitch) {
		yyYear -= 100;
	    }
	    yyYear += dataPtr->currentYearCentury;
	}
	yydate.isBce = 0;
	info->flags |= CLF_ASSEMBLE_JULIANDAY|CLF_ASSEMBLE_SECONDS;
    }

    /*
     * If the caller supplied a time zone in the string, make it into a time
     * zone indicator of +-hhmm and setup this time zone.
     */

    if (info->flags & CLF_ZONE) {
	if (yyTimezone || !yyDSTmode) {
	    /* Real time zone from numeric zone */
	    Tcl_Obj *tzObjStor = NULL;
	    int minEast = -yyTimezone;
	    int dstFlag = 1 - yyDSTmode;
	    tzObjStor = ClockFormatNumericTimeZone(
				60 * minEast + 3600 * dstFlag);
	    Tcl_IncrRefCount(tzObjStor);

	    opts->timezoneObj = ClockSetupTimeZone(dataPtr, interp, tzObjStor);

	    Tcl_DecrRefCount(tzObjStor);
	} else {
	    /* simplest case - GMT / UTC */
	    opts->timezoneObj = ClockSetupTimeZone(dataPtr, interp,
		dataPtr->literals[LIT_GMT]);
	}
	if (opts->timezoneObj == NULL) {
	    goto done;
	}

	// TclSetObjRef(yydate.tzName, opts->timezoneObj);

	info->flags |= CLF_ASSEMBLE_SECONDS;
    }

    /*
     * For freescan apply validation rules (stage 1) before mixed with
     * relative time (otherwise always valid recalculated date & time).
     */
    if ( (opts->flags & CLF_VALIDATE) ) {
	if (ClockValidDate(info, opts, CLF_VALIDATE_S1) != TCL_OK) {
	    goto done;
	}
    }

    /*
     * Assemble date, time, zone into seconds-from-epoch
     */

    if ((info->flags & (CLF_TIME|CLF_HAVEDATE)) == CLF_HAVEDATE) {
	yySecondOfDay = 0;
	info->flags |= CLF_ASSEMBLE_SECONDS;
    }
    else
    if (info->flags & CLF_TIME) {
	yySecondOfDay = ToSeconds(yyHour, yyMinutes,
			    yySeconds, yyMeridian);
	info->flags |= CLF_ASSEMBLE_SECONDS;
    }
    else
    if ( (info->flags & (CLF_DAYOFWEEK|CLF_HAVEDATE)) == CLF_DAYOFWEEK
	    || (info->flags & CLF_ORDINALMONTH)
	    || ( (info->flags & CLF_RELCONV)
		&& ( yyRelMonth != 0
		     || yyRelDay != 0 ) )
    ) {
	yySecondOfDay = 0;
	info->flags |= CLF_ASSEMBLE_SECONDS;
    }
    else {
	yySecondOfDay = yydate.localSeconds % SECONDS_PER_DAY;
    }

    /*
     * Do relative times
     */

    ret = ClockCalcRelTime(info);

    /* Free scanning completed - date ready */

done:

    return ret;
}

/*----------------------------------------------------------------------
 *
 * ClockCalcRelTime --
 *
 *	Used for calculating of relative times.
 *
 * Results:
 *	Returns a standard Tcl result.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */
int
ClockCalcRelTime(
    DateInfo	       *info)	/* Date fields used for converting */
{

    int prevDayOfWeek = yyDayOfWeek;	/* preserve unchanged day of week */

    /*
     * Because some calculations require in-between conversion of the
     * julian day, we can repeat this processing multiple times
     */
repeat_rel:

    if (info->flags & CLF_RELCONV) {

	/*
	 * Relative conversion normally possible in UTC time only, because
	 * of possible wrong local time increment if ignores in-between DST-hole.
	 * (see test-cases clock-34.53, clock-34.54).
	 * So increment date in julianDay, but time inside day in UTC (seconds).
	 */

	/* add months (or years in months) */

	if (yyRelMonth != 0) {
	    int m, h;

	    /* if needed extract year, month, etc. again */
	    if (info->flags & CLF_ASSEMBLE_DATE) {
		GetGregorianEraYearDay(&yydate, GREGORIAN_CHANGE_DATE);
		GetMonthDay(&yydate);
		GetYearWeekDay(&yydate, GREGORIAN_CHANGE_DATE);
		info->flags &= ~CLF_ASSEMBLE_DATE;
	    }

	    /* add the requisite number of months */
	    yyMonth += yyRelMonth - 1;
	    yyYear += yyMonth / 12;
	    m = yyMonth % 12;
	    /* compiler fix for negative offs - wrap y, m = (0, -1) -> (-1, 11) */
	    if (m < 0) {
		yyYear--;
		m = 12 + m;
	    }
	    yyMonth = m + 1;

	    /* if the day doesn't exist in the current month, repair it */
	    h = hath[IsGregorianLeapYear(&yydate)][m];
	    if (yyDay > h) {
		yyDay = h;
	    }

	    /* on demand (lazy) assemble julianDay using new year, month, etc. */
	    info->flags |= CLF_ASSEMBLE_JULIANDAY|CLF_ASSEMBLE_SECONDS;

	    yyRelMonth = 0;
	}

	/* add days (or other parts aligned to days) */
	if (yyRelDay) {

	    /* assemble julianDay using new year, month, etc. */
	    if (info->flags & CLF_ASSEMBLE_JULIANDAY) {
		GetJulianDayFromEraYearMonthDay(&yydate, GREGORIAN_CHANGE_DATE);
		info->flags &= ~CLF_ASSEMBLE_JULIANDAY;
	    }
	    yydate.julianDay += yyRelDay;

	    /* julianDay was changed, on demand (lazy) extract year, month, etc. again */
	    info->flags |= CLF_ASSEMBLE_DATE|CLF_ASSEMBLE_SECONDS;

	    yyRelDay = 0;
	}

	/* relative time (seconds), if exceeds current date, do the day conversion and
	 * leave rest of the increment in yyRelSeconds to add it hereafter in UTC seconds */
	if (yyRelSeconds) {
	    Tcl_WideInt newSecs = yySecondOfDay + yyRelSeconds;

	    /* if seconds increment outside of current date, increment day */
	    if (newSecs / SECONDS_PER_DAY != yySecondOfDay / SECONDS_PER_DAY) {

		yyRelDay += newSecs / SECONDS_PER_DAY;
		yySecondOfDay = 0;
		yyRelSeconds = newSecs % SECONDS_PER_DAY;

		goto repeat_rel;
	    }
	}

	info->flags &= ~CLF_RELCONV;
    }

    /*
     * Do relative (ordinal) month
     */

    if (info->flags & CLF_ORDINALMONTH) {
	int monthDiff;

	/* if needed extract year, month, etc. again */
	if (info->flags & CLF_ASSEMBLE_DATE) {
	    GetGregorianEraYearDay(&yydate, GREGORIAN_CHANGE_DATE);
	    GetMonthDay(&yydate);
	    GetYearWeekDay(&yydate, GREGORIAN_CHANGE_DATE);
	    info->flags &= ~CLF_ASSEMBLE_DATE;
	}

	if (yyMonthOrdinalIncr > 0) {
	    monthDiff = yyMonthOrdinal - yyMonth;
	    if (monthDiff <= 0) {
		monthDiff += 12;
	    }
	    yyMonthOrdinalIncr--;
	} else {
	    monthDiff = yyMonth - yyMonthOrdinal;
	    if (monthDiff >= 0) {
		monthDiff -= 12;
	    }
	    yyMonthOrdinalIncr++;
	}

	/* process it further via relative times */
	yyYear += yyMonthOrdinalIncr;
	yyRelMonth += monthDiff;
	info->flags &= ~CLF_ORDINALMONTH;
	info->flags |= CLF_RELCONV|CLF_ASSEMBLE_JULIANDAY|CLF_ASSEMBLE_SECONDS;

	goto repeat_rel;
    }

    /*
     * Do relative weekday
     */

    if ((info->flags & (CLF_DAYOFWEEK|CLF_HAVEDATE)) == CLF_DAYOFWEEK) {

	/* restore scanned day of week */
	yyDayOfWeek = prevDayOfWeek;

	/* if needed assemble julianDay now */
	if (info->flags & CLF_ASSEMBLE_JULIANDAY) {
	    GetJulianDayFromEraYearMonthDay(&yydate, GREGORIAN_CHANGE_DATE);
	    info->flags &= ~CLF_ASSEMBLE_JULIANDAY;
	}

	yydate.isBce = 0;
	yydate.julianDay = WeekdayOnOrBefore(yyDayOfWeek, yydate.julianDay + 6)
		    + 7 * yyDayOrdinal;
	if (yyDayOrdinal > 0) {
	    yydate.julianDay -= 7;
	}
	info->flags |= CLF_ASSEMBLE_DATE|CLF_ASSEMBLE_SECONDS;
    }

    return TCL_OK;
}


/*----------------------------------------------------------------------
 *
 * ClockWeekdaysOffs --
 *
 *	Get offset in days for the number of week days corresponding the
 *	given day of week (skipping Saturdays and Sundays).
 *
 *
 * Results:
 *	Returns a day increment adjusted the given weekdays
 *
 *----------------------------------------------------------------------
 */

static inline int
ClockWeekdaysOffs(
    int dayOfWeek,
    int offs)
{
    int weeks, resDayOfWeek;

    /* offset in days */
    weeks = offs / 5;
    offs = offs % 5;
    /* compiler fix for negative offs - wrap (0, -1) -> (-1, 4) */
    if (offs < 0) {
	weeks--;
	offs = 5 + offs;
    }
    offs += 7 * weeks;

    /* resulting day of week */
    {
	int day = (offs % 7);
	/* compiler fix for negative offs - wrap (0, -1) -> (-1, 6) */
	if (day < 0) {
	    day = 7 + day;
	}
	resDayOfWeek = dayOfWeek + day;
    }

    /* adjust if we start from a weekend */
    if (dayOfWeek > 5) {
	int adj = 5 - dayOfWeek;
	offs += adj;
	resDayOfWeek += adj;
    }

    /* adjust if we end up on a weekend */
    if (resDayOfWeek > 5) {
       offs += 2;
    }

    return offs;
}



/*----------------------------------------------------------------------
 *
 * ClockAddObjCmd -- , clock add --
 *
 *	Adds an offset to a given time.
 *
 *	Refer to the user documentation to see what it exactly does.
 *
 * Syntax:
 *   clock add clockval ?count unit?... ?-option value?
 *
 * Parameters:
 *   clockval -- Starting time value
 *   count -- Amount of a unit of time to add
 *   unit -- Unit of time to add, must be one of:
 *	     years year months month weeks week
 *	     days day hours hour minutes minute
 *	     seconds second
 *
 * Options:
 *   -gmt BOOLEAN
 *	 Flag synonymous with '-timezone :GMT'
 *   -timezone ZONE
 *	 Name of the time zone in which calculations are to be done.
 *   -locale NAME
 *	 Name of the locale in which calculations are to be done.
 *	 Used to determine the Gregorian change date.
 *
 * Results:
 *	Returns a standard Tcl result with the given time adjusted
 *	by the given offset(s) in order.
 *
 * Notes:
 *   It is possible that adding a number of months or years will adjust the
 *   day of the month as well.	For instance, the time at one month after
 *   31 January is either 28 or 29 February, because February has fewer
 *   than 31 days.
 *
 *----------------------------------------------------------------------
 */

int
ClockAddObjCmd(
    void *clientData,	/* Client data containing literal pool */
    Tcl_Interp *interp,		/* Tcl interpreter */
    int objc,			/* Parameter count */
    Tcl_Obj *const objv[])	/* Parameter values */
{
    static const char *syntax = "clock add clockval|-now ?number units?..."
	"?-gmt boolean? "
	"?-locale LOCALE? ?-timezone ZONE?";
    ClockClientData *dataPtr = (ClockClientData *)clientData;
    int ret;
    ClockFmtScnCmdArgs opts;	/* Format, locale, timezone and base */
    DateInfo	    yy;		/* Common structure used for parsing */
    DateInfo	   *info = &yy;

    /* add "week" to units also (because otherwise ambiguous) */
    static const char *const units[] = {
	"years",	"months",	    "week",	    "weeks",
	"days",		"weekdays",
	"hours",	"minutes",	    "seconds",
	NULL
    };
    enum unitInd {
	CLC_ADD_YEARS,	CLC_ADD_MONTHS,	    CLC_ADD_WEEK,   CLC_ADD_WEEKS,
	CLC_ADD_DAYS,	CLC_ADD_WEEKDAYS,
	CLC_ADD_HOURS,	CLC_ADD_MINUTES,    CLC_ADD_SECONDS
    };
    int unitIndex;		/* Index of an option. */
    int i;
    Tcl_WideInt offs;

    /* even number of arguments */
    if ((objc & 1) == 1) {
	Tcl_WrongNumArgs(interp, 0, objv, syntax);
	Tcl_SetErrorCode(interp, "CLOCK", "wrongNumArgs", (char *)NULL);
	return TCL_ERROR;
    }

    ClockInitDateInfo(&yy);

    /*
     * Extract values for the keywords.
     */

    ClockInitFmtScnArgs(clientData, interp, &opts);
    ret = ClockParseFmtScnArgs(&opts, &yy.date, objc, objv,
	    CLC_ADD_ARGS, "-gmt, -locale, or -timezone");
    if (ret != TCL_OK) {
	goto done;
    }

    /* time together as seconds of the day */
    yySecondOfDay = yySeconds = yydate.localSeconds % SECONDS_PER_DAY;
    /* seconds are in localSeconds (relative base date), so reset time here */
    yyHour = 0; yyMinutes = 0; yyMeridian = MER24;

    ret = TCL_ERROR;

    /*
     * Find each offset and process date increment
     */

    for (i = 2; i < objc; i+=2) {
	/* bypass not integers (options, allready processed above in ClockParseFmtScnArgs) */
	if (TclGetWideIntFromObj(NULL, objv[i], &offs) != TCL_OK) {
	    continue;
	}
	/* get unit */
	if (Tcl_GetIndexFromObj(interp, objv[i+1], units, "unit", 0,
		&unitIndex) != TCL_OK) {
	    goto done;
	}
	if (objv[i]->typePtr == &tclBignumType
	    || offs > (unitIndex < CLC_ADD_HOURS ? 0x7fffffff : TCL_MAX_SECONDS)
	    || offs < (unitIndex < CLC_ADD_HOURS ? -0x7fffffff : TCL_MIN_SECONDS)
	) {
	    Tcl_SetObjResult(interp, dataPtr->literals[LIT_INTEGER_VALUE_TOO_LARGE]);
	    goto done;
	}

	/* nothing to do if zero quantity */
	if (!offs) {
	    continue;
	}

	/* if in-between conversion needed (already have relative date/time),
	 * correct date info, because the date may be changed,
	 * so refresh it now */

	if ( (info->flags & CLF_RELCONV)
	  && ( unitIndex == CLC_ADD_WEEKDAYS
	    /* some months can be shorter as another */
	    || yyRelMonth || yyRelDay
	    /* day changed */
	    || yySeconds + yyRelSeconds > SECONDS_PER_DAY
	    || yySeconds + yyRelSeconds < 0
	  )
	) {
	    if (ClockCalcRelTime(info) != TCL_OK) {
		goto done;
	    }
	}

	/* process increment by offset + unit */
	info->flags |= CLF_RELCONV;
	switch (unitIndex) {
	case CLC_ADD_YEARS:
	    yyRelMonth += offs * 12;
	    break;
	case CLC_ADD_MONTHS:
	    yyRelMonth += offs;
	    break;
	case CLC_ADD_WEEK:
	case CLC_ADD_WEEKS:
	    yyRelDay += offs * 7;
	    break;
	case CLC_ADD_DAYS:
	    yyRelDay += offs;
	    break;
	case CLC_ADD_WEEKDAYS:
	    /* add number of week days (skipping Saturdays and Sundays)
	     * to a relative days value. */
	    offs = ClockWeekdaysOffs(yy.date.dayOfWeek, offs);
	    yyRelDay += offs;
	    break;
	case CLC_ADD_HOURS:
	    yyRelSeconds += offs * 60 * 60;
	    break;
	case CLC_ADD_MINUTES:
	    yyRelSeconds += offs * 60;
	    break;
	case CLC_ADD_SECONDS:
	    yyRelSeconds += offs;
	    break;
	}
    }

    /*
     * Do relative times (if not yet already processed interim):
     */

    if (info->flags & CLF_RELCONV) {
	if (ClockCalcRelTime(info) != TCL_OK) {
	    goto done;
	}
    }

    /* Convert date info structure into UTC seconds */

    ret = ClockScanCommit(&yy, &opts);

done:

    TclUnsetObjRef(yy.date.tzName);

    if (ret != TCL_OK) {
	return ret;
    }

    Tcl_SetObjResult(interp, Tcl_NewWideIntObj(yy.date.seconds));
    return TCL_OK;
}

/*----------------------------------------------------------------------
 *
 * ClockSecondsObjCmd -
 *
 *	Returns a count of microseconds since the epoch.

    int objc,			/* Parameter count */
    Tcl_Obj *const *objv)	/* Parameter values */
{
    Tcl_Time now;
    Tcl_Obj *timeObj;

    if (objc != 1) {
	Tcl_WrongNumArgs(interp, 0, objv, "clock seconds");
	return TCL_ERROR;
    }
    Tcl_GetTime(&now);
    TclNewUIntObj(timeObj, (Tcl_WideUInt)now.sec);

    Tcl_SetObjResult(interp, timeObj);
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * ClockSafeCatchCmd --
 *
 *	Same as "::catch" command but avoids overwriting of interp state.
 *
 *	See [554117edde] for more info (and proper solution).
 *
 *----------------------------------------------------------------------
 */
int
ClockSafeCatchCmd(
    TCL_UNUSED(void *),
    Tcl_Interp *interp,
    int objc,
    Tcl_Obj *const objv[])
{
    typedef struct {
        int status;			/* return code status */
        int flags;			/* Each remaining field saves the */
        int returnLevel;		/* corresponding field of the Interp */
        int returnCode;			/* struct. These fields taken together are */
        Tcl_Obj *errorInfo;		/* the "state" of the interp. */
        Tcl_Obj *errorCode;
        Tcl_Obj *returnOpts;
        Tcl_Obj *objResult;
        Tcl_Obj *errorStack;
        int resetErrorStack;
    } InterpState;

    Interp *iPtr = (Interp *)interp;
    int ret, flags = 0;
    InterpState *statePtr;

    if (objc == 1) {
	/* wrong # args : */
	return Tcl_CatchObjCmd(NULL, interp, objc, objv);
    }

    statePtr = (InterpState *)Tcl_SaveInterpState(interp, 0);
    if (!statePtr->errorInfo) {
	/* todo: avoid traced get of errorInfo here */
	TclInitObjRef(statePtr->errorInfo,
		Tcl_ObjGetVar2(interp, iPtr->eiVar, NULL, 0));
	flags |= ERR_LEGACY_COPY;
    }
    if (!statePtr->errorCode) {
	/* todo: avoid traced get of errorCode here */
	TclInitObjRef(statePtr->errorCode,
		Tcl_ObjGetVar2(interp, iPtr->ecVar, NULL, 0));
	flags |= ERR_LEGACY_COPY;
    }

    /* original catch */
    ret = Tcl_CatchObjCmd(NULL, interp, objc, objv);

    if (ret == TCL_ERROR) {
	Tcl_DiscardInterpState((Tcl_InterpState)statePtr);
	return TCL_ERROR;
    }
    /* overwrite result in state with catch result */
    TclSetObjRef(statePtr->objResult, Tcl_GetObjResult(interp));
    /* set result (together with restore state) to interpreter */
    (void) Tcl_RestoreInterpState(interp, (Tcl_InterpState)statePtr);
    /* todo: unless ERR_LEGACY_COPY not set in restore (branch [bug-554117edde] not merged yet) */
    iPtr->flags |= (flags & ERR_LEGACY_COPY);
    return ret;
}

/*
 *----------------------------------------------------------------------
 *
 * TzsetIfNecessary --
 *
 *	Calls the tzset() library function if the contents of the TZ

#else
#define WCHAR char
#define wcslen strlen
#define wcscmp strcmp
#define wcscpy strcpy
#endif

static size_t
TzsetIfNecessary(void)
{
    static WCHAR* tzWas = (WCHAR *)INT2PTR(-1);	 /* Previous value of TZ, protected by
					  * clockMutex. */
    static long tzLastRefresh = 0;	 /* Used for latency before next refresh */
    static size_t tzWasEpoch = 0;        /* Epoch, signals that TZ changed */
    static size_t tzEnvEpoch = 0;        /* Last env epoch, for faster signaling,
					    that TZ changed via TCL */
    const WCHAR *tzIsNow;		 /* Current value of TZ */

    /*
     * Prevent performance regression on some platforms by resolving of system time zone:
     * small latency for check whether environment was changed (once per second)
     * no latency if environment was changed with tcl-env (compare both epoch values)
     */
    Tcl_Time now;
    Tcl_GetTime(&now);
    if (now.sec == tzLastRefresh && tzEnvEpoch == TclEnvEpoch) {
	return tzWasEpoch;
    }

    tzEnvEpoch = TclEnvEpoch;
    tzLastRefresh = now.sec;

    /* check in lock */
    Tcl_MutexLock(&clockMutex);
    tzIsNow = getenv("TCL_TZ");
    if (tzIsNow == NULL) {
	tzIsNow = getenv("TZ");
    }
    if (tzIsNow != NULL && (tzWas == NULL || tzWas == (WCHAR *)INT2PTR(-1)
	    || wcscmp(tzIsNow, tzWas) != 0)) {
	tzset();
	if (tzWas != NULL && tzWas != (WCHAR *)INT2PTR(-1)) {
	    ckfree(tzWas);
	}
	tzWas = (WCHAR *)ckalloc(sizeof(WCHAR) * (wcslen(tzIsNow) + 1));
	wcscpy(tzWas, tzIsNow);
	tzWasEpoch++;
    } else if (tzIsNow == NULL && tzWas != NULL) {
	tzset();
	if (tzWas != (WCHAR *)INT2PTR(-1)) {
	    ckfree(tzWas);
	}
	tzWas = NULL;
	tzWasEpoch++;
    }
    Tcl_MutexUnlock(&clockMutex);

    return tzWasEpoch;




























}

/*
 * Local Variables:
 * mode: c
 * c-basic-offset: 4
 * fill-column: 78
 * End:
 */

/*
 * tclClockFmt.c --
 *
 *	Contains the date format (and scan) routines. This code is back-ported
 *	from the time and date facilities of tclSE engine, by Serg G. Brester.
 *
 * Copyright (c) 2015 by Sergey G. Brester aka sebres. All rights reserved.
 *
 * See the file "license.terms" for information on usage and redistribution of
 * this file, and for a DISCLAIMER OF ALL WARRANTIES.
 */

#include "tclInt.h"
#include "tclStrIdxTree.h"
#include "tclDate.h"

/*
 * Miscellaneous forward declarations and functions used within this file
 */

static void
ClockFmtObj_DupInternalRep(Tcl_Obj *srcPtr, Tcl_Obj *copyPtr);
static void
ClockFmtObj_FreeInternalRep(Tcl_Obj *objPtr);
static int
ClockFmtObj_SetFromAny(Tcl_Interp *interp, Tcl_Obj *objPtr);
static void
ClockFmtObj_UpdateString(Tcl_Obj *objPtr);


TCL_DECLARE_MUTEX(ClockFmtMutex); /* Serializes access to common format list. */

static void ClockFmtScnStorageDelete(ClockFmtScnStorage *fss);

static void ClockFrmScnFinalize(void *clientData);

/*
 * Clock scan and format facilities.
 */

/*
 *----------------------------------------------------------------------
 *
 * _str2int -- , _str2wideInt --
 *
 *	Fast inline-convertion of string to signed int or wide int by given
 *	start/end.
 *
 *	The given string should contain numbers chars only (because already
 *	pre-validated within parsing routines)
 *
 * Results:
 *	Returns a standard Tcl result.
 *	TCL_OK - by successful conversion, TCL_ERROR by (wide) int overflow
 *
 *----------------------------------------------------------------------
 */

static inline void
_str2int_no(
    int	       *out,
    const char *p,
    const char *e,
    int sign)
{
    /* assert(e <= p+10); */
    int val = 0;
    /* overflow impossible for 10 digits ("9..9"), so no needs to check at all */
    while (p < e) {			/* never overflows */
	val = val * 10 + (*p++ - '0');
    }
    if (sign < 0) { val = -val; }
    *out = val;
}

static inline void
_str2wideInt_no(
    Tcl_WideInt *out,
    const char	*p,
    const char	*e,
    int sign)
{
    /* assert(e <= p+18); */
    Tcl_WideInt val = 0;
    /* overflow impossible for 18 digits ("9..9"), so no needs to check at all */
    while (p < e) {			/* never overflows */
	val = val * 10 + (*p++ - '0');
    }
    if (sign < 0) { val = -val; }
    *out = val;
}

/* int & Tcl_WideInt overflows may happens here (expected case) */
#if defined(__GNUC__) || defined(__GNUG__)
# pragma GCC optimize("no-trapv")
#endif

static inline int
_str2int(
    int	       *out,
    const char *p,
    const char *e,
    int sign)
{
    int val = 0;
    /* overflow impossible for 10 digits ("9..9"), so no needs to check before */
    const char *eNO = p+10;
    if (eNO > e) {
	eNO = e;
    }
    while (p < eNO) {				/* never overflows */
	val = val * 10 + (*p++ - '0');
    }
    if (sign >= 0) {
	while (p < e) {				/* check for overflow */
	    int prev = val;
	    val = val * 10 + (*p++ - '0');
	    if (val / 10 < prev) {
		return TCL_ERROR;
	    }
	}
    } else {
	val = -val;
	while (p < e) {				/* check for overflow */
	    int prev = val;
	    val = val * 10 - (*p++ - '0');
	    if (val / 10 > prev) {
		return TCL_ERROR;
	    }
	}
    }
    *out = val;
    return TCL_OK;
}

static inline int
_str2wideInt(
    Tcl_WideInt *out,
    const char	*p,
    const char	*e,
    int sign)
{
    Tcl_WideInt val = 0;
    /* overflow impossible for 18 digits ("9..9"), so no needs to check before */
    const char *eNO = p+18;
    if (eNO > e) {
	eNO = e;
    }
    while (p < eNO) {				/* never overflows */
	val = val * 10 + (*p++ - '0');
    }
    if (sign >= 0) {
	while (p < e) {				/* check for overflow */
	    Tcl_WideInt prev = val;
	    val = val * 10 + (*p++ - '0');
	    if (val / 10 < prev) {
		return TCL_ERROR;
	    }
	}
    } else {
	val = -val;
	while (p < e) {				/* check for overflow */
	    Tcl_WideInt prev = val;
	    val = val * 10 - (*p++ - '0');
	    if (val / 10 > prev) {
		return TCL_ERROR;
	    }
	}
    }
    *out = val;
    return TCL_OK;
}

int
TclAtoWIe(
    Tcl_WideInt *out,
    const char	*p,
    const char	*e,
    int sign)
{
    return _str2wideInt(out, p, e, sign);
}

#if defined(__GNUC__) || defined(__GNUG__)
# pragma GCC reset_options
#endif

/*
 *----------------------------------------------------------------------
 *
 * _itoaw -- , _witoaw --
 *
 *	Fast inline-convertion of signed int or wide int to string, using
 *	given padding with specified padchar and width (or without padding).
 *
 *	This is a very fast replacement for sprintf("%02d").
 *
 * Results:
 *	Returns position in buffer after end of conversion result.
 *
 *----------------------------------------------------------------------
 */

static inline char *
_itoaw(
    char *buf,
    int val,
    char  padchar,
    unsigned short int width)
{
    char *p;
    static int wrange[] = {1, 10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000, 1000000000};

    /* positive integer */

    if (val >= 0)
    {
	/* check resp. recalculate width */
	while (width <= 9 && val >= wrange[width]) {
	    width++;
	}
	/* number to string backwards */
	p = buf + width;
	*p-- = '\0';
	do {
	    char c = (val % 10); val /= 10;
	    *p-- = '0' + c;
	} while (val > 0);
	/* fulling with pad-char */
	while (p >= buf) {
	    *p-- = padchar;
	}

	return buf + width;
    }
    /* negative integer */

    if (!width) width++;
    /* check resp. recalculate width (regarding sign) */
    width--;
    while (width <= 9 && val <= -wrange[width]) {
	width++;
    }
    width++;
    /* number to string backwards */
    p = buf + width;
    *p-- = '\0';
    /* differentiate platforms with -1 % 10 == 1 and -1 % 10 == -1 */
    if (-1 % 10 == -1) {
	do {
	    char c = (val % 10); val /= 10;
	    *p-- = '0' - c;
	} while (val < 0);
    } else {
	do {
	    char c = (val % 10); val /= 10;
	    *p-- = '0' + c;
	} while (val < 0);
    }
    /* sign by 0 padding */
    if (padchar != '0') { *p-- = '-'; }
    /* fulling with pad-char */
    while (p >= buf + 1) {
	*p-- = padchar;
    }
    /* sign by non 0 padding */
    if (padchar == '0') { *p = '-'; }

    return buf + width;
}
char *
TclItoAw(
    char *buf,
    int val,
    char  padchar,
    unsigned short int width)
{
    return _itoaw(buf, val, padchar, width);
}

static inline char *
_witoaw(
    char *buf,
    Tcl_WideInt val,
    char  padchar,
    unsigned short int width)
{
    char *p;
    static int wrange[] = {1, 10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000, 1000000000};

    /* positive integer */

    if (val >= 0)
    {
	/* check resp. recalculate width */
	if (val >= 10000000000LL) {
	    Tcl_WideInt val2;
	    val2 = val / 10000000000LL;
	    while (width <= 9 && val2 >= wrange[width]) {
		width++;
	    }
	    width += 10;
	} else {
	    while (width <= 9 && val >= wrange[width]) {
		width++;
	    }
	}
	/* number to string backwards */
	p = buf + width;
	*p-- = '\0';
	do {
	    char c = (val % 10); val /= 10;
	    *p-- = '0' + c;
	} while (val > 0);
	/* fulling with pad-char */
	while (p >= buf) {
	    *p-- = padchar;
	}

	return buf + width;
    }

    /* negative integer */

    if (!width) width++;
    /* check resp. recalculate width (regarding sign) */
    width--;
    if (val <= -10000000000LL) {
	Tcl_WideInt val2;
	val2 = val / 10000000000LL;
	while (width <= 9 && val2 <= -wrange[width]) {
	    width++;
	}
	width += 10;
    } else {
	while (width <= 9 && val <= -wrange[width]) {
	    width++;
	}
    }
    width++;
    /* number to string backwards */
    p = buf + width;
    *p-- = '\0';
    /* differentiate platforms with -1 % 10 == 1 and -1 % 10 == -1 */
    if (-1 % 10 == -1) {
	do {
	    char c = (val % 10); val /= 10;
	    *p-- = '0' - c;
	} while (val < 0);
    } else {
	do {
	    char c = (val % 10); val /= 10;
	    *p-- = '0' + c;
	} while (val < 0);
    }
    /* sign by 0 padding */
    if (padchar != '0') { *p-- = '-'; }
    /* fulling with pad-char */
    while (p >= buf + 1) {
	*p-- = padchar;
    }
    /* sign by non 0 padding */
    if (padchar == '0') { *p = '-'; }

    return buf + width;
}

/*
 * Global GC as LIFO for released scan/format object storages.
 *
 * Used to holds last released CLOCK_FMT_SCN_STORAGE_GC_SIZE formats
 * (after last reference from Tcl-object will be removed). This is helpful
 * to avoid continuous (re)creation and compiling by some dynamically resp.
 * variable format objects, that could be often reused.
 *
 * As long as format storage is used resp. belongs to GC, it takes place in
 * FmtScnHashTable also.
 */

#if CLOCK_FMT_SCN_STORAGE_GC_SIZE > 0

static struct {
    ClockFmtScnStorage	  *stackPtr;
    ClockFmtScnStorage	  *stackBound;
    unsigned int	   count;
} ClockFmtScnStorage_GC = {NULL, NULL, 0};

/*
 *----------------------------------------------------------------------
 *
 * ClockFmtScnStorageGC_In --
 *
 *	Adds an format storage object to GC.
 *
 *	If current GC is full (size larger as CLOCK_FMT_SCN_STORAGE_GC_SIZE)
 *	this removes last unused storage at begin of GC stack (LIFO).
 *
 *	Assumes caller holds the ClockFmtMutex.
 *
 * Results:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static inline void
ClockFmtScnStorageGC_In(ClockFmtScnStorage *entry)
{
    /* add new entry */
    TclSpliceIn(entry, ClockFmtScnStorage_GC.stackPtr);
    if (ClockFmtScnStorage_GC.stackBound == NULL) {
	ClockFmtScnStorage_GC.stackBound = entry;
    }
    ClockFmtScnStorage_GC.count++;

    /* if GC ist full */
    if (ClockFmtScnStorage_GC.count > CLOCK_FMT_SCN_STORAGE_GC_SIZE) {

	/* GC stack is LIFO: delete first inserted entry */
	ClockFmtScnStorage *delEnt = ClockFmtScnStorage_GC.stackBound;
	ClockFmtScnStorage_GC.stackBound = delEnt->prevPtr;
	TclSpliceOut(delEnt, ClockFmtScnStorage_GC.stackPtr);
	ClockFmtScnStorage_GC.count--;
	delEnt->prevPtr = delEnt->nextPtr = NULL;
	/* remove it now */
	ClockFmtScnStorageDelete(delEnt);
    }
}

/*
 *----------------------------------------------------------------------
 *
 * ClockFmtScnStorage_GC_Out --
 *
 *	Restores (for reusing) given format storage object from GC.
 *
 *	Assumes caller holds the ClockFmtMutex.
 *
 * Results:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static inline void
ClockFmtScnStorage_GC_Out(ClockFmtScnStorage *entry)
{
    TclSpliceOut(entry, ClockFmtScnStorage_GC.stackPtr);
    ClockFmtScnStorage_GC.count--;
    if (ClockFmtScnStorage_GC.stackBound == entry) {
	ClockFmtScnStorage_GC.stackBound = entry->prevPtr;
    }
    entry->prevPtr = entry->nextPtr = NULL;
}

#endif


/*
 * Global format storage hash table of type ClockFmtScnStorageHashKeyType
 * (contains list of scan/format object storages, shared across all threads).
 *
 * Used for fast searching by format string.
 */
static Tcl_HashTable FmtScnHashTable;
static int	     initialized = 0;

/*
 * Wrappers between pointers to hash entry and format storage object
 */
static inline Tcl_HashEntry *
HashEntry4FmtScn(ClockFmtScnStorage *fss) {
    return (Tcl_HashEntry*)(fss + 1);
};
static inline ClockFmtScnStorage *
FmtScn4HashEntry(Tcl_HashEntry *hKeyPtr) {
    return (ClockFmtScnStorage*)(((char*)hKeyPtr) - sizeof(ClockFmtScnStorage));
};

/*
 *----------------------------------------------------------------------
 *
 * ClockFmtScnStorageAllocProc --
 *
 *	Allocate space for a hash entry containing format storage together
 *	with the string key.
 *
 * Results:
 *	The return value is a pointer to the created entry.
 *
 *----------------------------------------------------------------------
 */

static Tcl_HashEntry *
ClockFmtScnStorageAllocProc(
    TCL_UNUSED(Tcl_HashTable *),	/* Hash table. */
    void *keyPtr)		/* Key to store in the hash table entry. */
{
    ClockFmtScnStorage *fss;
    const char *string = (const char *) keyPtr;
    Tcl_HashEntry *hPtr;
    unsigned int size,
	allocsize = sizeof(ClockFmtScnStorage) + sizeof(Tcl_HashEntry);

    allocsize += (size = strlen(string) + 1);
    if (size > sizeof(hPtr->key)) {
	allocsize -= sizeof(hPtr->key);
    }

    fss = (ClockFmtScnStorage *)ckalloc(allocsize);

    /* initialize */
    memset(fss, 0, sizeof(*fss));

    hPtr = HashEntry4FmtScn(fss);
    memcpy(&hPtr->key.string, string, size);
    hPtr->clientData = 0; /* currently unused */

    return hPtr;
}

/*
 *----------------------------------------------------------------------
 *
 * ClockFmtScnStorageFreeProc --
 *
 *	Free format storage object and space of given hash entry.
 *
 * Results:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static void
ClockFmtScnStorageFreeProc(
    Tcl_HashEntry *hPtr)
{
    ClockFmtScnStorage *fss = FmtScn4HashEntry(hPtr);

    if (fss->scnTok != NULL) {
	ckfree(fss->scnTok);
	fss->scnTok = NULL;
	fss->scnTokC = 0;
    }
    if (fss->fmtTok != NULL) {
	ckfree(fss->fmtTok);
	fss->fmtTok = NULL;
	fss->fmtTokC = 0;
    }

    ckfree(fss);
}

/*
 *----------------------------------------------------------------------
 *
 * ClockFmtScnStorageDelete --
 *
 *	Delete format storage object.
 *
 * Results:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static void
ClockFmtScnStorageDelete(ClockFmtScnStorage *fss) {
    Tcl_HashEntry   *hPtr = HashEntry4FmtScn(fss);
    /*
     * This will delete a hash entry and call "Tcl_Free" for storage self, if
     * some additionally handling required, freeEntryProc can be used instead
     */
    Tcl_DeleteHashEntry(hPtr);
}


/*
 * Derivation of tclStringHashKeyType with another allocEntryProc
 */

static Tcl_HashKeyType ClockFmtScnStorageHashKeyType;


/*
 * Type definition of clock-format tcl object type.
 */

static const Tcl_ObjType ClockFmtObjType = {
    "clock-format",	       /* name */
    ClockFmtObj_FreeInternalRep, /* freeIntRepProc */
    ClockFmtObj_DupInternalRep,	 /* dupIntRepProc */
    ClockFmtObj_UpdateString,	 /* updateStringProc */
    ClockFmtObj_SetFromAny,	 /* setFromAnyProc */
    TCL_OBJTYPE_V0
};

#define ObjClockFmtScn(objPtr) \
    (*((ClockFmtScnStorage **)&(objPtr)->internalRep.twoPtrValue.ptr1))

#define ObjLocFmtKey(objPtr) \
    (*((Tcl_Obj **)&(objPtr)->internalRep.twoPtrValue.ptr2))

static void
ClockFmtObj_DupInternalRep(
    Tcl_Obj *srcPtr,
    Tcl_Obj *copyPtr)
{
    ClockFmtScnStorage *fss = ObjClockFmtScn(srcPtr);

    if (fss != NULL) {
	Tcl_MutexLock(&ClockFmtMutex);
	fss->objRefCount++;
	Tcl_MutexUnlock(&ClockFmtMutex);
    }

    ObjClockFmtScn(copyPtr) = fss;
    /* regards special case - format not localizable */
    if (ObjLocFmtKey(srcPtr) != srcPtr) {
	TclInitObjRef(ObjLocFmtKey(copyPtr), ObjLocFmtKey(srcPtr));
    } else {
	ObjLocFmtKey(copyPtr) = copyPtr;
    }
    copyPtr->typePtr = &ClockFmtObjType;


    /* if no format representation, dup string representation */
    if (fss == NULL) {
	copyPtr->bytes = (char *)ckalloc(srcPtr->length + 1);
	memcpy(copyPtr->bytes, srcPtr->bytes, srcPtr->length + 1);
	copyPtr->length = srcPtr->length;
    }
}

static void
ClockFmtObj_FreeInternalRep(
    Tcl_Obj *objPtr)
{
    ClockFmtScnStorage *fss = ObjClockFmtScn(objPtr);
    if (fss != NULL) {
	Tcl_MutexLock(&ClockFmtMutex);
	/* decrement object reference count of format/scan storage */
	if (--fss->objRefCount <= 0) {
	    #if CLOCK_FMT_SCN_STORAGE_GC_SIZE > 0
	      /* don't remove it right now (may be reusable), just add to GC */
	      ClockFmtScnStorageGC_In(fss);
	    #else
	      /* remove storage (format representation) */
	      ClockFmtScnStorageDelete(fss);
	    #endif
	}
	Tcl_MutexUnlock(&ClockFmtMutex);
    }
    ObjClockFmtScn(objPtr) = NULL;
    if (ObjLocFmtKey(objPtr) != objPtr) {
	TclUnsetObjRef(ObjLocFmtKey(objPtr));
    } else {
	ObjLocFmtKey(objPtr) = NULL;
    }
    objPtr->typePtr = NULL;
};

static int
ClockFmtObj_SetFromAny(
    TCL_UNUSED(Tcl_Interp *),
    Tcl_Obj    *objPtr)
{
    /* validate string representation before free old internal representation */
    (void)TclGetString(objPtr);

    /* free old internal representation */
    if (objPtr->typePtr && objPtr->typePtr->freeIntRepProc)
	objPtr->typePtr->freeIntRepProc(objPtr);

    /* initial state of format object */
    ObjClockFmtScn(objPtr) = NULL;
    ObjLocFmtKey(objPtr) = NULL;
    objPtr->typePtr = &ClockFmtObjType;

    return TCL_OK;
};

static void
ClockFmtObj_UpdateString(
    Tcl_Obj  *objPtr)
{
    const char *name = "UNKNOWN";
    size_t len;
    ClockFmtScnStorage *fss = ObjClockFmtScn(objPtr);

    if (fss != NULL) {
	Tcl_HashEntry *hPtr = HashEntry4FmtScn(fss);
	name = hPtr->key.string;
    }
    len = strlen(name);
    objPtr->length = len++,
    objPtr->bytes = (char *)ckalloc(len);
    if (objPtr->bytes) {
	memcpy(objPtr->bytes, name, len);
    }
}

/*
 *----------------------------------------------------------------------
 *
 * ClockFrmObjGetLocFmtKey --
 *
 *	Retrieves format key object used to search localized format.
 *
 *	This is normally stored in second pointer of internal representation.
 *	If format object is not localizable, it is equal the given format
 *	pointer (special case to fast fallback by not-localizable formats).
 *
 * Results:
 *	Returns tcl object with key or format object if not localizable.
 *
 * Side effects:
 * 	Converts given format object to ClockFmtObjType on demand for caching
 *	the key inside its internal representation.
 *
 *----------------------------------------------------------------------
 */

Tcl_Obj*
ClockFrmObjGetLocFmtKey(
    Tcl_Interp *interp,
    Tcl_Obj    *objPtr)
{
    Tcl_Obj *keyObj;

    if (objPtr->typePtr != &ClockFmtObjType) {
	if (ClockFmtObj_SetFromAny(interp, objPtr) != TCL_OK) {
	    return NULL;
	}
    }

    keyObj = ObjLocFmtKey(objPtr);
    if (keyObj) {
	return keyObj;
    }

    keyObj = Tcl_ObjPrintf("FMT_%s", TclGetString(objPtr));
    TclInitObjRef(ObjLocFmtKey(objPtr), keyObj);

    return keyObj;
}

/*
 *----------------------------------------------------------------------
 *
 * FindOrCreateFmtScnStorage --
 *
 *	Retrieves format storage for given string format.
 *
 *	This will find the given format in the global storage hash table
 *	or create a format storage object on demaind and save the
 *	reference in the first pointer of internal representation of given
 *	object.
 *
 * Results:
 *	Returns scan/format storage pointer to ClockFmtScnStorage.
 *
 * Side effects:
 * 	Converts given format object to ClockFmtObjType on demand for caching
 *	the format storage reference inside its internal representation.
 *	Increments objRefCount of the ClockFmtScnStorage reference.
 *
 *----------------------------------------------------------------------
 */

static ClockFmtScnStorage *
FindOrCreateFmtScnStorage(
    Tcl_Interp *interp,
    Tcl_Obj    *objPtr)
{
    const char *strFmt = TclGetString(objPtr);
    ClockFmtScnStorage *fss = NULL;
    int isNew;
    Tcl_HashEntry *hPtr;

    Tcl_MutexLock(&ClockFmtMutex);

    /* if not yet initialized */
    if (!initialized) {
	/* initialize type */
	memcpy(&ClockFmtScnStorageHashKeyType, &tclStringHashKeyType, sizeof(tclStringHashKeyType));
	ClockFmtScnStorageHashKeyType.allocEntryProc = ClockFmtScnStorageAllocProc;
	ClockFmtScnStorageHashKeyType.freeEntryProc = ClockFmtScnStorageFreeProc;

	/* initialize hash table */
	Tcl_InitCustomHashTable(&FmtScnHashTable, TCL_CUSTOM_TYPE_KEYS,
	    &ClockFmtScnStorageHashKeyType);

	initialized = 1;
	Tcl_CreateExitHandler(ClockFrmScnFinalize, NULL);
    }

    /* get or create entry (and alocate storage) */
    hPtr = Tcl_CreateHashEntry(&FmtScnHashTable, strFmt, &isNew);
    if (hPtr != NULL) {

	fss = FmtScn4HashEntry(hPtr);

	#if CLOCK_FMT_SCN_STORAGE_GC_SIZE > 0
	  /* unlink if it is currently in GC */
	  if (isNew == 0 && fss->objRefCount == 0) {
	      ClockFmtScnStorage_GC_Out(fss);
	  }
	#endif

	/* new reference, so increment in lock right now */
	fss->objRefCount++;

	ObjClockFmtScn(objPtr) = fss;
    }

    Tcl_MutexUnlock(&ClockFmtMutex);

    if (fss == NULL && interp != NULL) {
	Tcl_AppendResult(interp, "retrieve clock format failed \"",
	    strFmt ? strFmt : "", "\"", NULL);
	Tcl_SetErrorCode(interp, "TCL", "EINVAL", (char *)NULL);
    }

    return fss;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_GetClockFrmScnFromObj --
 *
 *	Returns a clock format/scan representation of (*objPtr), if possible.
 *	If something goes wrong, NULL is returned, and if interp is non-NULL,
 *	an error message is written there.
 *
 * Results:
 *	Valid representation of type ClockFmtScnStorage.
 *
 * Side effects:
 *	Caches the ClockFmtScnStorage reference as the internal rep of (*objPtr)
 *	and in global hash table, shared across all threads.
 *
 *----------------------------------------------------------------------
 */

ClockFmtScnStorage *
Tcl_GetClockFrmScnFromObj(
    Tcl_Interp *interp,
    Tcl_Obj *objPtr)
{
    ClockFmtScnStorage *fss;

    if (objPtr->typePtr != &ClockFmtObjType) {
	if (ClockFmtObj_SetFromAny(interp, objPtr) != TCL_OK) {
	    return NULL;
	}
    }

    fss = ObjClockFmtScn(objPtr);

    if (fss == NULL) {
	fss = FindOrCreateFmtScnStorage(interp, objPtr);
    }

    return fss;
}
/*
 *----------------------------------------------------------------------
 *
 * ClockLocalizeFormat --
 *
 *	Wrap the format object in options to the localized format,
 *	corresponding given locale.
 *
 *	This searches localized format in locale catalog, and if not yet
 *	exists, it executes ::tcl::clock::LocalizeFormat in given interpreter
 *	and caches its result in the locale catalog.
 *
 * Results:
 *	Localized format object.
 *
 * Side effects:
 *	Caches the localized format inside locale catalog.
 *
 *----------------------------------------------------------------------
 */

Tcl_Obj *
ClockLocalizeFormat(
    ClockFmtScnCmdArgs *opts)
{
    ClockClientData *dataPtr = (ClockClientData *)opts->clientData;
    Tcl_Obj *valObj = NULL, *keyObj;

    keyObj = ClockFrmObjGetLocFmtKey(opts->interp, opts->formatObj);

    /* special case - format object is not localizable */
    if (keyObj == opts->formatObj) {
	return opts->formatObj;
    }

    /* prevents loss of key object if the format object (where key stored)
     * becomes changed (loses its internal representation during evals) */
    Tcl_IncrRefCount(keyObj);

    if (opts->mcDictObj == NULL) {
	ClockMCDict(opts);
	if (opts->mcDictObj == NULL)
	    goto done;
    }

    /* try to find in cache within locale mc-catalog */
    if (Tcl_DictObjGet(NULL, opts->mcDictObj,
	    keyObj, &valObj) != TCL_OK) {
	goto done;
    }

    /* call LocalizeFormat locale format fmtkey */
    if (valObj == NULL) {
	Tcl_Obj *callargs[4];
	callargs[0] = dataPtr->literals[LIT_LOCALIZE_FORMAT];
	callargs[1] = opts->localeObj;
	callargs[2] = opts->formatObj;
	callargs[3] = opts->mcDictObj;
	if (Tcl_EvalObjv(opts->interp, 4, callargs, 0) == TCL_OK
	) {
	    valObj = Tcl_GetObjResult(opts->interp);
	}

	/* ensure mcDictObj remains unshared */
	if (opts->mcDictObj->refCount > 1) {
	    /* smart reference (shared dict as object with no ref-counter) */
	    opts->mcDictObj = TclDictObjSmartRef(opts->interp,
		opts->mcDictObj);
	}
	if (!valObj) {
	    goto done;
	}
	/* cache it inside mc-dictionary (this incr. ref count of keyObj/valObj) */
	if (Tcl_DictObjPut(opts->interp, opts->mcDictObj,
		keyObj, valObj) != TCL_OK
	) {
	    valObj = NULL;
	    goto done;
	}

	Tcl_ResetResult(opts->interp);

	/* check special case - format object is not localizable */
	if (valObj == opts->formatObj) {
	    /* mark it as unlocalizable, by setting self as key (without refcount incr) */
	    if (valObj->typePtr == &ClockFmtObjType) {
		TclUnsetObjRef(ObjLocFmtKey(valObj));
		ObjLocFmtKey(valObj) = valObj;
	    }
	}
    }

done:

    TclUnsetObjRef(keyObj);
    return (opts->formatObj = valObj);
}

/*
 *----------------------------------------------------------------------
 *
 * FindTokenBegin --
 *
 *	Find begin of given scan token in string, corresponding token type.
 *
 * Results:
 *	Position of token inside string if found. Otherwise - end of string.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static const char *
FindTokenBegin(
    const char *p,
    const char *end,
    ClockScanToken *tok)
{
    char c;
    if (p < end) {
	/* next token a known token type */
	switch (tok->map->type) {
	case CTOKT_INT:
	case CTOKT_WIDE:
	    /* should match at least one digit */
	    while (!isdigit(UCHAR(*p)) && (p = Tcl_UtfNext(p)) < end) {};
	    return p;
	break;
	case CTOKT_WORD:
	    c = *(tok->tokWord.start);
	    /* should match at least to the first char of this word */
	    while (*p != c && (p = Tcl_UtfNext(p)) < end) {};
	    return p;
	break;
	case CTOKT_SPACE:
	    while (!isspace(UCHAR(*p)) && (p = Tcl_UtfNext(p)) < end) {};
	    return p;
	break;
	case CTOKT_CHAR:
	    c = *((char *)tok->map->data);
	    while (*p != c && (p = Tcl_UtfNext(p)) < end) {};
	    return p;
	break;
	}
    }
    return p;
}

/*
 *----------------------------------------------------------------------
 *
 * DetermineGreedySearchLen --
 *
 *	Determine min/max lengths as exact as possible (speed, greedy match).
 *
 * Results:
 *	None. Lengths are stored in *minLenPtr, *maxLenPtr.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static void
DetermineGreedySearchLen(
    DateInfo *info, ClockScanToken *tok,
    int *minLenPtr, int *maxLenPtr)
{
    int minLen = tok->map->minSize;
    int maxLen;
    const char *p = yyInput + minLen,
			*end = info->dateEnd;

    /* if still tokens available, try to correct minimum length */
    if ((tok+1)->map) {
	end -= tok->endDistance + yySpaceCount;
	/* find position of next known token */
	p = FindTokenBegin(p, end, tok+1);
	if (p < end) {
	    minLen = p - yyInput;
	}
    }

    /* max length to the end regarding distance to end (min-width of following tokens) */
    maxLen = end - yyInput;
    /* several amendments */
    if (maxLen > tok->map->maxSize) {
	maxLen = tok->map->maxSize;
    };
    if (minLen < tok->map->minSize) {
	minLen = tok->map->minSize;
    }
    if (minLen > maxLen) {
	maxLen = minLen;
    }
    if (maxLen > info->dateEnd - yyInput) {
	maxLen = info->dateEnd - yyInput;
    }

    /* check digits rigth now */
    if (tok->map->type == CTOKT_INT || tok->map->type == CTOKT_WIDE) {
	p = yyInput;
	end = p + maxLen;
	if (end > info->dateEnd) { end = info->dateEnd; };
	while (isdigit(UCHAR(*p)) && p < end) { p++; };
	maxLen = p - yyInput;
    }

    /* try to get max length more precise for greedy match,
     * check the next ahead token available there */
    if (minLen < maxLen && tok->lookAhTok) {
	ClockScanToken *laTok = tok + tok->lookAhTok + 1;
	p = yyInput + maxLen;
	/* regards all possible spaces here (because they are optional) */
	end = p + tok->lookAhMax + yySpaceCount + 1;
	if (end > info->dateEnd) {
	    end = info->dateEnd;
	}
	p += tok->lookAhMin;
	if (laTok->map && p < end) {
	    const char *f;
	    /* try to find laTok between [lookAhMin, lookAhMax] */
	    while (minLen < maxLen) {
		f = FindTokenBegin(p, end, laTok);
		/* if found (not below lookAhMax) */
		if (f < end) {
		    break;
		}
		/* try again with fewer length */
		maxLen--;
		p--;
		end--;
	    }
	} else if (p > end) {
	    maxLen -= (p - end);
	    if (maxLen < minLen) {
		maxLen = minLen;
	    }
	}
    }

    *minLenPtr = minLen;
    *maxLenPtr = maxLen;
}

/*
 *----------------------------------------------------------------------
 *
 * ObjListSearch --
 *
 *	Find largest part of the input string from start regarding min and
 *	max lengths in the given list (utf-8, case sensitive).
 *
 * Results:
 *	TCL_OK - match found, TCL_RETURN - not matched, TCL_ERROR in error case.
 *
 * Side effects:
 *	Input points to end of the found token in string.
 *
 *----------------------------------------------------------------------
 */

static inline int
ObjListSearch(
    DateInfo *info, int *val,
    Tcl_Obj **lstv, Tcl_Size lstc,
    int minLen, int maxLen)
{
    Tcl_Size i, l, lf = -1;
    const char *s, *f, *sf;
    /* search in list */
    for (i = 0; i < lstc; i++) {
	s = TclGetStringFromObj(lstv[i], &l);

	if ( l >= minLen
	  && (f = TclUtfFindEqualNC(yyInput, yyInput + maxLen, s, s + l, &sf)) > yyInput
	) {
	    l = f - yyInput;
	    if (l < minLen) {
		continue;
	    }
	    /* found, try to find longest value (greedy search) */
	    if (l < maxLen && minLen != maxLen) {
		lf = i;
		minLen = l + 1;
		continue;
	    }
	    /* max possible - end of search */
	    *val = i;
	    yyInput += l;
	    break;
	}
    }

    /* if found */
    if (i < lstc) {
	return TCL_OK;
    }
    if (lf >= 0) {
	*val = lf;
	yyInput += minLen - 1;
	return TCL_OK;
    }
    return TCL_RETURN;
}
#if 0
/* currently unused */

static int
LocaleListSearch(ClockFmtScnCmdArgs *opts,
    DateInfo *info, int mcKey, int *val,
    int minLen, int maxLen)
{
    Tcl_Obj **lstv;
    Tcl_Size lstc;
    Tcl_Obj *valObj;

    /* get msgcat value */
    valObj = ClockMCGet(opts, mcKey);
    if (valObj == NULL) {
	return TCL_ERROR;
    }

    /* is a list */
    if (TclListObjGetElements(opts->interp, valObj, &lstc, &lstv) != TCL_OK) {
	return TCL_ERROR;
    }

    /* search in list */
    return ObjListSearch(info, val, lstv, lstc,
	minLen, maxLen);
}
#endif

/*
 *----------------------------------------------------------------------
 *
 * ClockMCGetListIdxTree --
 *
 *	Retrieves localized string indexed tree in the locale catalog for
 *	given literal index mcKey (and builds it on demand).
 *
 *	Searches localized index in locale catalog, and if not yet exists,
 *	creates string indexed tree and stores it in the locale catalog.
 *
 * Results:
 *	Localized string index tree.
 *
 * Side effects:
 *	Caches the localized string index tree inside locale catalog.
 *
 *----------------------------------------------------------------------
 */

static TclStrIdxTree *
ClockMCGetListIdxTree(
    ClockFmtScnCmdArgs *opts,
    int	 mcKey)
{
    TclStrIdxTree * idxTree;
    Tcl_Obj *objPtr = ClockMCGetIdx(opts, mcKey);
    if ( objPtr != NULL
      && (idxTree = TclStrIdxTreeGetFromObj(objPtr)) != NULL
    ) {
	return idxTree;

    } else {
	/* build new index */

	Tcl_Obj **lstv;
	Tcl_Size lstc;
	Tcl_Obj *valObj;

	objPtr = TclStrIdxTreeNewObj();
	if ((idxTree = TclStrIdxTreeGetFromObj(objPtr)) == NULL) {
	    goto done; /* unexpected, but ...*/
	}

	valObj = ClockMCGet(opts, mcKey);
	if (valObj == NULL) {
	    goto done;
	}

	if (TclListObjGetElements(opts->interp, valObj,
		&lstc, &lstv) != TCL_OK) {
	    goto done;
	};

	if (TclStrIdxTreeBuildFromList(idxTree, lstc, lstv, NULL) != TCL_OK) {
	    goto done;
	}

	ClockMCSetIdx(opts, mcKey, objPtr);
	objPtr = NULL;
    };

done:
    if (objPtr) {
	Tcl_DecrRefCount(objPtr);
	idxTree = NULL;
    }

    return idxTree;
}

/*
 *----------------------------------------------------------------------
 *
 * ClockMCGetMultiListIdxTree --
 *
 *	Retrieves localized string indexed tree in the locale catalog for
 *	multiple lists by literal indices mcKeys (and builds it on demand).
 *
 *	Searches localized index in locale catalog for mcKey, and if not
 *	yet exists, creates string indexed tree and stores it in the
 *	locale catalog.
 *
 * Results:
 *	Localized string index tree.
 *
 * Side effects:
 *	Caches the localized string index tree inside locale catalog.
 *
 *----------------------------------------------------------------------
 */

static TclStrIdxTree *
ClockMCGetMultiListIdxTree(
    ClockFmtScnCmdArgs *opts,
    int	 mcKey,
    int *mcKeys)
{
    TclStrIdxTree * idxTree;
    Tcl_Obj *objPtr = ClockMCGetIdx(opts, mcKey);
    if ( objPtr != NULL
      && (idxTree = TclStrIdxTreeGetFromObj(objPtr)) != NULL
    ) {
	return idxTree;

    } else {
	/* build new index */

	Tcl_Obj **lstv;
	Tcl_Size	  lstc;
	Tcl_Obj *valObj;

	objPtr = TclStrIdxTreeNewObj();
	if ((idxTree = TclStrIdxTreeGetFromObj(objPtr)) == NULL) {
	    goto done; /* unexpected, but ...*/
	}

	while (*mcKeys) {

	    valObj = ClockMCGet(opts, *mcKeys);
	    if (valObj == NULL) {
		goto done;
	    }

	    if (TclListObjGetElements(opts->interp, valObj,
		    &lstc, &lstv) != TCL_OK) {
		goto done;
	    };

	    if (TclStrIdxTreeBuildFromList(idxTree, lstc, lstv, NULL) != TCL_OK) {
		goto done;
	    }
	    mcKeys++;
	}

	ClockMCSetIdx(opts, mcKey, objPtr);
	objPtr = NULL;
    };

done:
    if (objPtr) {
	Tcl_DecrRefCount(objPtr);
	idxTree = NULL;
    }

    return idxTree;
}

/*
 *----------------------------------------------------------------------
 *
 * ClockStrIdxTreeSearch --
 *
 *	Find largest part of the input string from start regarding lengths
 *	in the given localized string indexed tree (utf-8, case sensitive).
 *
 * Results:
 *	TCL_OK - match found and the index stored in *val,
 *	TCL_RETURN - not matched or ambigous,
 * 	TCL_ERROR - in error case.
 *
 * Side effects:
 *	Input points to end of the found token in string.
 *
 *----------------------------------------------------------------------
 */

static inline int
ClockStrIdxTreeSearch(
    DateInfo *info, TclStrIdxTree *idxTree, int *val,
    int minLen, int maxLen)
{
    const char *f;
    TclStrIdx  *foundItem;
    f = TclStrIdxTreeSearch(NULL, &foundItem, idxTree,
	    yyInput, yyInput + maxLen);

    if (f <= yyInput || (f - yyInput) < minLen) {
	/* not found */
	return TCL_RETURN;
    }
    if (!foundItem->value) {
	/* ambigous */
	return TCL_RETURN;
    }

    *val = PTR2INT(foundItem->value);

    /* shift input pointer */
    yyInput = f;

    return TCL_OK;
}
#if 0
/* currently unused */

static int
StaticListSearch(ClockFmtScnCmdArgs *opts,
    DateInfo *info, const char **lst, int *val)
{
    size_t len;
    const char **s = lst;
    while (*s != NULL) {
	len = strlen(*s);
	if ( len <= info->dateEnd - yyInput
	  && strncasecmp(yyInput, *s, len) == 0
	) {
	    *val = (s - lst);
	    yyInput += len;
	    break;
	}
	s++;
    }
    if (*s != NULL) {
	return TCL_OK;
    }
    return TCL_RETURN;
}
#endif

static inline const char *
FindWordEnd(
    ClockScanToken *tok,
    const char * p, const char * end)
{
    const char *x = tok->tokWord.start;
    const char *pfnd = p;
    if (x == tok->tokWord.end - 1) { /* fast phase-out for single char word */
	if (*p == *x) {
	    return ++p;
	}
    }
    /* multi-char word */
    x = TclUtfFindEqualNC(x, tok->tokWord.end, p, end, &pfnd);
    if (x < tok->tokWord.end) {
	/* no match -> error */
	return NULL;
    }
    return pfnd;
}

static int
ClockScnToken_Month_Proc(ClockFmtScnCmdArgs *opts,
    DateInfo *info, ClockScanToken *tok)
{
#if 0
/* currently unused, test purposes only */
    static const char * months[] = {
	/* full */
	"January", "February", "March",
	"April",   "May",      "June",
	"July",	   "August",   "September",
	"October", "November", "December",
	/* abbr */
	"Jan", "Feb", "Mar", "Apr", "May", "Jun",
	"Jul", "Aug", "Sep", "Oct", "Nov", "Dec",
	NULL
    };
    int val;
    if (StaticListSearch(opts, info, months, &val) != TCL_OK) {
	return TCL_RETURN;
    }
    yyMonth = (val % 12) + 1;
    return TCL_OK;
#endif

    static int monthsKeys[] = {MCLIT_MONTHS_FULL, MCLIT_MONTHS_ABBREV, 0};

    int ret, val;
    int minLen, maxLen;
    TclStrIdxTree *idxTree;

    DetermineGreedySearchLen(info, tok, &minLen, &maxLen);

    /* get or create tree in msgcat dict */

    idxTree = ClockMCGetMultiListIdxTree(opts, MCLIT_MONTHS_COMB, monthsKeys);
    if (idxTree == NULL) {
	return TCL_ERROR;
    }

    ret = ClockStrIdxTreeSearch(info, idxTree, &val, minLen, maxLen);
    if (ret != TCL_OK) {
	return ret;
    }

    yyMonth = val;
    return TCL_OK;

}

static int
ClockScnToken_DayOfWeek_Proc(ClockFmtScnCmdArgs *opts,
    DateInfo *info, ClockScanToken *tok)
{
    static int dowKeys[] = {MCLIT_DAYS_OF_WEEK_ABBREV, MCLIT_DAYS_OF_WEEK_FULL, 0};

    int ret, val;
    int minLen, maxLen;
    char curTok = *tok->tokWord.start;
    TclStrIdxTree *idxTree;

    DetermineGreedySearchLen(info, tok, &minLen, &maxLen);

    /* %u %w %Ou %Ow */
    if ( curTok != 'a' && curTok != 'A'
      && ((minLen <= 1 && maxLen >= 1) || PTR2INT(tok->map->data))
    ) {

	val = -1;

	if (PTR2INT(tok->map->data) == 0) {
	    if (*yyInput >= '0' && *yyInput <= '9') {
		val = *yyInput - '0';
	    }
	} else {
	    idxTree = ClockMCGetListIdxTree(opts, PTR2INT(tok->map->data) /* mcKey */);
	    if (idxTree == NULL) {
		return TCL_ERROR;
	    }

	    ret = ClockStrIdxTreeSearch(info, idxTree, &val, minLen, maxLen);
	    if (ret != TCL_OK) {
		return ret;
	    }
	    --val;
	}

	if (val != -1) {
	    if (val == 0) {
		val = 7;
	    }
	    if (val > 7) {
		Tcl_SetObjResult(opts->interp, Tcl_NewStringObj("day of week is greater than 7", -1));
		Tcl_SetErrorCode(opts->interp, "CLOCK", "badDayOfWeek", (char *)NULL);
		return TCL_ERROR;
	    }
	    info->date.dayOfWeek = val;
	    yyInput++;
	    return TCL_OK;
	}


	return TCL_RETURN;
    }

    /* %a %A */
    idxTree = ClockMCGetMultiListIdxTree(opts, MCLIT_DAYS_OF_WEEK_COMB, dowKeys);
    if (idxTree == NULL) {
	return TCL_ERROR;
    }

    ret = ClockStrIdxTreeSearch(info, idxTree, &val, minLen, maxLen);
    if (ret != TCL_OK) {
	return ret;
    }
    --val;

    if (val == 0) {
	val = 7;
    }
    info->date.dayOfWeek = val;
    return TCL_OK;

}

static int
ClockScnToken_amPmInd_Proc(ClockFmtScnCmdArgs *opts,
    DateInfo *info, ClockScanToken *tok)
{
    int ret, val;
    int minLen, maxLen;
    Tcl_Obj *amPmObj[2];

    DetermineGreedySearchLen(info, tok, &minLen, &maxLen);

    amPmObj[0] = ClockMCGet(opts, MCLIT_AM);
    amPmObj[1] = ClockMCGet(opts, MCLIT_PM);

    if (amPmObj[0] == NULL || amPmObj[1] == NULL) {
	return TCL_ERROR;
    }

    ret = ObjListSearch(info, &val, amPmObj, 2,
	minLen, maxLen);
    if (ret != TCL_OK) {
	return ret;
    }

    if (val == 0) {
	yyMeridian = MERam;
    } else {
	yyMeridian = MERpm;
    }

    return TCL_OK;
}

static int
ClockScnToken_LocaleERA_Proc(ClockFmtScnCmdArgs *opts,
    DateInfo *info, ClockScanToken *tok)
{
    ClockClientData *dataPtr = (ClockClientData *)opts->clientData;

    int ret, val;
    int minLen, maxLen;
    Tcl_Obj *eraObj[6];

    DetermineGreedySearchLen(info, tok, &minLen, &maxLen);

    eraObj[0] = ClockMCGet(opts, MCLIT_BCE);
    eraObj[1] = ClockMCGet(opts, MCLIT_CE);
    eraObj[2] = dataPtr->mcLiterals[MCLIT_BCE2];
    eraObj[3] = dataPtr->mcLiterals[MCLIT_CE2];
    eraObj[4] = dataPtr->mcLiterals[MCLIT_BCE3];
    eraObj[5] = dataPtr->mcLiterals[MCLIT_CE3];

    if (eraObj[0] == NULL || eraObj[1] == NULL) {
	return TCL_ERROR;
    }

    ret = ObjListSearch(info, &val, eraObj, 6,
	minLen, maxLen);
    if (ret != TCL_OK) {
	return ret;
    }

    if (val & 1) {
	yydate.isBce = 0;
    } else {
	yydate.isBce = 1;
    }

    return TCL_OK;
}

static int
ClockScnToken_LocaleListMatcher_Proc(ClockFmtScnCmdArgs *opts,
    DateInfo *info, ClockScanToken *tok)
{
    int ret, val;
    int minLen, maxLen;
    TclStrIdxTree *idxTree;

    DetermineGreedySearchLen(info, tok, &minLen, &maxLen);

    /* get or create tree in msgcat dict */

    idxTree = ClockMCGetListIdxTree(opts, PTR2INT(tok->map->data) /* mcKey */);
    if (idxTree == NULL) {
	return TCL_ERROR;
    }

    ret = ClockStrIdxTreeSearch(info, idxTree, &val, minLen, maxLen);
    if (ret != TCL_OK) {
	return ret;
    }

    if (tok->map->offs > 0) {
	*(int *)(((char *)info) + tok->map->offs) = --val;
    }

    return TCL_OK;
}

static int
ClockScnToken_JDN_Proc(TCL_UNUSED(ClockFmtScnCmdArgs *),
    DateInfo *info, ClockScanToken *tok)
{
    int minLen, maxLen;
    const char *p = yyInput, *end; const char *s;
    Tcl_WideInt intJD; int fractJD = 0, fractJDDiv = 1;

    DetermineGreedySearchLen(info, tok, &minLen, &maxLen);

    end = yyInput + maxLen;

    /* currently positive astronomic dates only */
    if (*p == '+' || *p == '-') { p++; };
    s = p;
    while (p < end && isdigit(UCHAR(*p))) {
	p++;
    }
    if ( _str2wideInt(&intJD, s, p, (*yyInput != '-' ? 1 : -1)) != TCL_OK) {
	return TCL_RETURN;
    };
    yyInput = p;
    if (p >= end || *p++ != '.') { /* allow pure integer JDN */
	/* by astronomical JD the seconds of day offs is 12 hours */
	if (tok->map->offs) {
	    goto done;
	}
	/* calendar JD */
	yydate.julianDay = intJD;
	return TCL_OK;
    }
    s = p;
    while (p < end && isdigit(UCHAR(*p))) {
    	fractJDDiv *= 10;
	p++;
    }
    if ( _str2int(&fractJD, s, p, 1) != TCL_OK) {
	return TCL_RETURN;
    };
    yyInput = p;

done:
    /*
     * Build a date from julian day (integer and fraction).
     * Note, astronomical JDN starts at noon in opposite to calendar julianday.
     */

    fractJD = (int)tok->map->offs /* 0 for calendar or 43200 for astro JD */
	+ (int)((Tcl_WideInt)SECONDS_PER_DAY * fractJD / fractJDDiv);
    if (fractJD > SECONDS_PER_DAY) {
	fractJD %= SECONDS_PER_DAY;
	intJD += 1;
    }
    yydate.secondOfDay = fractJD;
    yydate.julianDay = intJD;

    yydate.seconds =
	-210866803200LL
	+ ( SECONDS_PER_DAY * intJD )
	+ ( fractJD );

    info->flags |= CLF_POSIXSEC;

    return TCL_OK;
}

static int
ClockScnToken_TimeZone_Proc(ClockFmtScnCmdArgs *opts,
    DateInfo *info, ClockScanToken *tok)
{
    int minLen, maxLen;
    int len = 0;
    const char *p = yyInput;
    Tcl_Obj *tzObjStor = NULL;

    DetermineGreedySearchLen(info, tok, &minLen, &maxLen);

    /* numeric timezone */
    if (*p == '+' || *p == '-') {
	/* max chars in numeric zone = "+00:00:00" */
    #define MAX_ZONE_LEN 9
	char buf[MAX_ZONE_LEN + 1];
	char *bp = buf;
	*bp++ = *p++; len++;
	if (maxLen > MAX_ZONE_LEN)
	    maxLen = MAX_ZONE_LEN;
	/* cumulate zone into buf without ':' */
	while (len + 1 < maxLen) {
	    if (!isdigit(UCHAR(*p))) break;
	    *bp++ = *p++; len++;
	    if (!isdigit(UCHAR(*p))) break;
	    *bp++ = *p++; len++;
	    if (len + 2 < maxLen) {
		if (*p == ':') {
		    p++; len++;
		}
	    }
	}
	*bp = '\0';

	if (len < minLen) {
	    return TCL_RETURN;
	}
    #undef MAX_ZONE_LEN

	/* timezone */
	tzObjStor = Tcl_NewStringObj(buf, bp-buf);
    } else {
	/* legacy (alnum) timezone like CEST, etc. */
	if (maxLen > 4)
	    maxLen = 4;
	while (len < maxLen) {
	    if ( (*p & 0x80)
	      || (!isalpha(UCHAR(*p)) && !isdigit(UCHAR(*p)))
	    ) {	      /* INTL: ISO only. */
		break;
	    }
	    p++; len++;
	}

	if (len < minLen) {
	    return TCL_RETURN;
	}

	/* timezone */
	tzObjStor = Tcl_NewStringObj(yyInput, p-yyInput);

	/* convert using dict */
    }

    /* try to apply new time zone */
    Tcl_IncrRefCount(tzObjStor);

    opts->timezoneObj = ClockSetupTimeZone(opts->clientData, opts->interp,
	tzObjStor);

    Tcl_DecrRefCount(tzObjStor);
    if (opts->timezoneObj == NULL) {
	return TCL_ERROR;
    }

    yyInput += len;

    return TCL_OK;
}

static int
ClockScnToken_StarDate_Proc(TCL_UNUSED(ClockFmtScnCmdArgs *),
    DateInfo *info, ClockScanToken *tok)
{
    int minLen, maxLen;
    const char *p = yyInput, *end; const char *s;
    int year, fractYear, fractDayDiv, fractDay;
    static const char *stardatePref = "stardate ";

    DetermineGreedySearchLen(info, tok, &minLen, &maxLen);

    end = yyInput + maxLen;

    /* stardate string */
    p = TclUtfFindEqualNCInLwr(p, end, stardatePref, stardatePref + 9, &s);
    if (p >= end || p - yyInput < 9) {
	return TCL_RETURN;
    }
    /* bypass spaces */
    while (p < end && isspace(UCHAR(*p))) {
	p++;
    }
    if (p >= end) {
	return TCL_RETURN;
    }
    /* currently positive stardate only */
    if (*p == '+') { p++; };
    s = p;
    while (p < end && isdigit(UCHAR(*p))) {
	p++;
    }
    if (p >= end || p - s < 4) {
	return TCL_RETURN;
    }
    if ( _str2int(&year, s, p-3, 1) != TCL_OK
      || _str2int(&fractYear, p-3, p, 1) != TCL_OK) {
	return TCL_RETURN;
    };
    if (*p++ != '.') {
	return TCL_RETURN;
    }
    s = p;
    fractDayDiv = 1;
    while (p < end && isdigit(UCHAR(*p))) {
	fractDayDiv *= 10;
	p++;
    }
    if ( _str2int(&fractDay, s, p, 1) != TCL_OK) {
	return TCL_RETURN;
    };
    yyInput = p;

    /* Build a date from year and fraction. */

    yydate.year = year + RODDENBERRY;
    yydate.isBce = 0;
    yydate.gregorian = 1;

    if (IsGregorianLeapYear(&yydate)) {
	fractYear *= 366;
    } else {
	fractYear *= 365;
    }
    yydate.dayOfYear = fractYear / 1000 + 1;
    if (fractYear % 1000 >= 500) {
	yydate.dayOfYear++;
    }

    GetJulianDayFromEraYearDay(&yydate, GREGORIAN_CHANGE_DATE);

    yydate.localSeconds =
	-210866803200LL
	+ ( SECONDS_PER_DAY * yydate.julianDay )
	+ ( SECONDS_PER_DAY * fractDay / fractDayDiv );

    return TCL_OK;
}

static const char *ScnSTokenMapIndex =
    "dmbyYHMSpJjCgGVazUsntQ";
static ClockScanTokenMap ScnSTokenMap[] = {
    /* %d %e */
    {CTOKT_INT, CLF_DAYOFMONTH, 0, 1, 2, offsetof(DateInfo, date.dayOfMonth),
	NULL, NULL},
    /* %m %N */
    {CTOKT_INT, CLF_MONTH, 0, 1, 2, offsetof(DateInfo, date.month),
	NULL, NULL},
    /* %b %B %h */
    {CTOKT_PARSER, CLF_MONTH, 0, 0, 0xffff, 0,
	    ClockScnToken_Month_Proc, NULL},
    /* %y */
    {CTOKT_INT, CLF_YEAR, 0, 1, 2, offsetof(DateInfo, date.year),
	NULL, NULL},
    /* %Y */
    {CTOKT_INT, CLF_YEAR | CLF_CENTURY, 0, 4, 4, offsetof(DateInfo, date.year),
	NULL, NULL},
    /* %H %k %I %l */
    {CTOKT_INT, CLF_TIME, 0, 1, 2, offsetof(DateInfo, date.hour),
	NULL, NULL},
    /* %M */
    {CTOKT_INT, CLF_TIME, 0, 1, 2, offsetof(DateInfo, date.minutes),
	NULL, NULL},
    /* %S */
    {CTOKT_INT, CLF_TIME, 0, 1, 2, offsetof(DateInfo, date.secondOfMin),
	NULL, NULL},
    /* %p %P */
    {CTOKT_PARSER, 0, 0, 0, 0xffff, 0,
	ClockScnToken_amPmInd_Proc, NULL},
    /* %J */
    {CTOKT_WIDE, CLF_JULIANDAY | CLF_SIGNED, 0, 1, 0xffff, offsetof(DateInfo, date.julianDay),
	NULL, NULL},
    /* %j */
    {CTOKT_INT, CLF_DAYOFYEAR, 0, 1, 3, offsetof(DateInfo, date.dayOfYear),
	NULL, NULL},
    /* %C */
    {CTOKT_INT, CLF_CENTURY|CLF_ISO8601CENTURY, 0, 1, 2, offsetof(DateInfo, dateCentury),
	NULL, NULL},
    /* %g */
    {CTOKT_INT, CLF_ISO8601YEAR, 0, 2, 2, offsetof(DateInfo, date.iso8601Year),
	NULL, NULL},
    /* %G */
    {CTOKT_INT, CLF_ISO8601YEAR | CLF_ISO8601CENTURY, 0, 4, 4, offsetof(DateInfo, date.iso8601Year),
	NULL, NULL},
    /* %V */
    {CTOKT_INT, CLF_ISO8601WEAK, 0, 1, 2, offsetof(DateInfo, date.iso8601Week),
	NULL, NULL},
    /* %a %A %u %w */
    {CTOKT_PARSER, CLF_DAYOFWEEK, 0, 0, 0xffff, 0,
	ClockScnToken_DayOfWeek_Proc, NULL},
    /* %z %Z */
    {CTOKT_PARSER, CLF_OPTIONAL, 0, 0, 0xffff, 0,
	ClockScnToken_TimeZone_Proc, NULL},
    /* %U %W */
    {CTOKT_INT, CLF_OPTIONAL, 0, 1, 2, 0, /* currently no capture, parse only token */
	NULL, NULL},
    /* %s */
    {CTOKT_WIDE, CLF_POSIXSEC | CLF_SIGNED, 0, 1, 0xffff, offsetof(DateInfo, date.seconds),
	NULL, NULL},
    /* %n */
    {CTOKT_CHAR, 0, 0, 1, 1, 0, NULL, "\n"},
    /* %t */
    {CTOKT_CHAR, 0, 0, 1, 1, 0, NULL, "\t"},
    /* %Q */
    {CTOKT_PARSER, CLF_LOCALSEC, 0, 16, 30, 0,
	ClockScnToken_StarDate_Proc, NULL},
};
static const char *ScnSTokenMapAliasIndex[2] = {
    "eNBhkIlPAuwZW",
    "dmbbHHHpaaazU"
};

static const char *ScnETokenMapIndex =
    "EJjys";
static ClockScanTokenMap ScnETokenMap[] = {
    /* %EE */
    {CTOKT_PARSER, 0, 0, 0, 0xffff, offsetof(DateInfo, date.year),
	ClockScnToken_LocaleERA_Proc, (void *)MCLIT_LOCALE_NUMERALS},
    /* %EJ */
    {CTOKT_PARSER, CLF_JULIANDAY | CLF_SIGNED, 0, 1, 0xffff, 0, /* calendar JDN starts at midnight */
	ClockScnToken_JDN_Proc, NULL},
    /* %Ej */
    {CTOKT_PARSER, CLF_JULIANDAY | CLF_SIGNED, 0, 1, 0xffff, (SECONDS_PER_DAY/2), /* astro JDN starts at noon */
	ClockScnToken_JDN_Proc, NULL},
    /* %Ey */
    {CTOKT_PARSER, 0, 0, 0, 0xffff, 0, /* currently no capture, parse only token */
	ClockScnToken_LocaleListMatcher_Proc, (void *)MCLIT_LOCALE_NUMERALS},
    /* %Es */
    {CTOKT_WIDE, CLF_LOCALSEC | CLF_SIGNED, 0, 1, 0xffff, offsetof(DateInfo, date.localSeconds),
	NULL, NULL},
};
static const char *ScnETokenMapAliasIndex[2] = {
    "",
    ""
};

static const char *ScnOTokenMapIndex =
    "dmyHMSu";
static ClockScanTokenMap ScnOTokenMap[] = {
    /* %Od %Oe */
    {CTOKT_PARSER, CLF_DAYOFMONTH, 0, 0, 0xffff, offsetof(DateInfo, date.dayOfMonth),
	ClockScnToken_LocaleListMatcher_Proc, (void *)MCLIT_LOCALE_NUMERALS},
    /* %Om */
    {CTOKT_PARSER, CLF_MONTH, 0, 0, 0xffff, offsetof(DateInfo, date.month),
	ClockScnToken_LocaleListMatcher_Proc, (void *)MCLIT_LOCALE_NUMERALS},
    /* %Oy */
    {CTOKT_PARSER, CLF_YEAR, 0, 0, 0xffff, offsetof(DateInfo, date.year),
	ClockScnToken_LocaleListMatcher_Proc, (void *)MCLIT_LOCALE_NUMERALS},
    /* %OH %Ok %OI %Ol */
    {CTOKT_PARSER, CLF_TIME, 0, 0, 0xffff, offsetof(DateInfo, date.hour),
	ClockScnToken_LocaleListMatcher_Proc, (void *)MCLIT_LOCALE_NUMERALS},
    /* %OM */
    {CTOKT_PARSER, CLF_TIME, 0, 0, 0xffff, offsetof(DateInfo, date.minutes),
	ClockScnToken_LocaleListMatcher_Proc, (void *)MCLIT_LOCALE_NUMERALS},
    /* %OS */
    {CTOKT_PARSER, CLF_TIME, 0, 0, 0xffff, offsetof(DateInfo, date.secondOfMin),
	ClockScnToken_LocaleListMatcher_Proc, (void *)MCLIT_LOCALE_NUMERALS},
    /* %Ou Ow */
    {CTOKT_PARSER, CLF_DAYOFWEEK, 0, 0, 0xffff, 0,
	ClockScnToken_DayOfWeek_Proc, (void *)MCLIT_LOCALE_NUMERALS},
};
static const char *ScnOTokenMapAliasIndex[2] = {
    "ekIlw",
    "dHHHu"
};

/* Token map reserved for CTOKT_SPACE */
static ClockScanTokenMap ScnSpaceTokenMap = {
    CTOKT_SPACE,  0, 0, 1, 1, 0,
	NULL, NULL
};

static ClockScanTokenMap ScnWordTokenMap = {
    CTOKT_WORD,	   0, 0, 1, 1, 0,
	NULL, NULL
};


static inline unsigned int
EstimateTokenCount(
    const char *fmt,
    const char *end)
{
    const char *p = fmt;
    unsigned int tokcnt;
    /* estimate token count by % char and format length */
    tokcnt = 0;
    while (p <= end) {
	if (*p++ == '%') {
	    tokcnt++;
	    p++;
	}
    }
    p = fmt + tokcnt * 2;
    if (p < end) {
	if ((unsigned int)(end - p) < tokcnt) {
	    tokcnt += (end - p);
	} else {
	    tokcnt += tokcnt;
	}
    }
    return ++tokcnt;
}

#define AllocTokenInChain(tok, chain, tokCnt, type) \
    if (++(tok) >= (chain) + (tokCnt)) { \
	chain = (type)ckrealloc((char *)(chain), \
	    (tokCnt + CLOCK_MIN_TOK_CHAIN_BLOCK_SIZE) * sizeof(*(tok))); \
	if ((chain) == NULL) { goto done; }; \
	(tok) = (chain) + (tokCnt); \
	(tokCnt) += CLOCK_MIN_TOK_CHAIN_BLOCK_SIZE; \
    } \
    memset(tok, 0, sizeof(*(tok)));

/*
 *----------------------------------------------------------------------
 */
ClockFmtScnStorage *
ClockGetOrParseScanFormat(
    Tcl_Interp *interp,		/* Tcl interpreter */
    Tcl_Obj    *formatObj)	/* Format container */
{
    ClockFmtScnStorage *fss;

    fss = Tcl_GetClockFrmScnFromObj(interp, formatObj);
    if (fss == NULL) {
	return NULL;
    }

    /* if format (scnTok) already tokenized */
    if (fss->scnTok != NULL) {
	return fss;
    }

    Tcl_MutexLock(&ClockFmtMutex);

    /* first time scanning - tokenize format */
    if (fss->scnTok == NULL) {
	ClockScanToken *tok, *scnTok;
	unsigned int tokCnt;
	const char *p, *e, *cp;

	e = p = HashEntry4FmtScn(fss)->key.string;
	e += strlen(p);

	/* estimate token count by % char and format length */
	fss->scnTokC = EstimateTokenCount(p, e);

	fss->scnSpaceCount = 0;

	scnTok = tok = (ClockScanToken *)ckalloc(sizeof(*tok) * fss->scnTokC);
	memset(tok, 0, sizeof(*(tok)));
	tokCnt = 1;
	while (p < e) {
	    switch (*p) {
	    case '%':
	    if (1) {
		ClockScanTokenMap * scnMap = ScnSTokenMap;
		const char *mapIndex =	ScnSTokenMapIndex,
			  **aliasIndex = ScnSTokenMapAliasIndex;
		if (p+1 >= e) {
		    goto word_tok;
		}
		p++;
		/* try to find modifier: */
		switch (*p) {
		case '%':
		    /* begin new word token - don't join with previous word token,
		     * because current mapping should be "...%%..." -> "...%..." */
		    tok->map = &ScnWordTokenMap;
		    tok->tokWord.start = p;
		    tok->tokWord.end = p+1;
		    AllocTokenInChain(tok, scnTok, fss->scnTokC, ClockScanToken *); tokCnt++;
		    p++;
		    continue;
		break;
		case 'E':
		    scnMap = ScnETokenMap,
		    mapIndex =	ScnETokenMapIndex,
		    aliasIndex = ScnETokenMapAliasIndex;
		    p++;
		break;
		case 'O':
		    scnMap = ScnOTokenMap,
		    mapIndex = ScnOTokenMapIndex,
		    aliasIndex = ScnOTokenMapAliasIndex;
		    p++;
		break;
		}
		/* search direct index */
		cp = strchr(mapIndex, *p);
		if (!cp || *cp == '\0') {
		    /* search wrapper index (multiple chars for same token) */
		    cp = strchr(aliasIndex[0], *p);
		    if (!cp || *cp == '\0') {
			p--; if (scnMap != ScnSTokenMap) p--;
			goto word_tok;
		    }
		    cp = strchr(mapIndex, aliasIndex[1][cp - aliasIndex[0]]);
		    if (!cp || *cp == '\0') { /* unexpected, but ... */
		    #ifdef DEBUG
			Tcl_Panic("token \"%c\" has no map in wrapper resolver", *p);
		    #endif
			p--; if (scnMap != ScnSTokenMap) p--;
			goto word_tok;
		    }
		}
		tok->map = &scnMap[cp - mapIndex];
		tok->tokWord.start = p;

		/* calculate look ahead value by standing together tokens */
		if (tok > scnTok) {
		    ClockScanToken     *prevTok = tok - 1;

		    while (prevTok >= scnTok) {
			if (prevTok->map->type != tok->map->type) {
			    break;
			}
			prevTok->lookAhMin += tok->map->minSize;
			prevTok->lookAhMax += tok->map->maxSize;
			prevTok->lookAhTok++;
			prevTok--;
		    }
		}

		/* increase space count used in format */
		if ( tok->map->type == CTOKT_CHAR
		  && isspace(UCHAR(*((char *)tok->map->data)))
		) {
		    fss->scnSpaceCount++;
		}

		/* next token */
		AllocTokenInChain(tok, scnTok, fss->scnTokC, ClockScanToken *); tokCnt++;
		p++;
		continue;
	    }
	    break;
	    default:
	    if ( *p == ' ' || isspace(UCHAR(*p)) ) {
		tok->map = &ScnSpaceTokenMap;
		tok->tokWord.start = p++;
		while (p < e && isspace(UCHAR(*p))) {
		    p++;
		}
		tok->tokWord.end = p;
		/* increase space count used in format */
		fss->scnSpaceCount++;
		/* next token */
		AllocTokenInChain(tok, scnTok, fss->scnTokC, ClockScanToken *); tokCnt++;
		continue;
	    }
word_tok:
	    if (1) {
		ClockScanToken	 *wordTok = tok;
		if (tok > scnTok && (tok-1)->map == &ScnWordTokenMap) {
		    wordTok = tok-1;
		}
		/* new word token */
		if (wordTok == tok) {
		    wordTok->tokWord.start = p;
		    wordTok->map = &ScnWordTokenMap;
		    AllocTokenInChain(tok, scnTok, fss->scnTokC, ClockScanToken *); tokCnt++;
		}
		if (isspace(UCHAR(*p))) {
		    fss->scnSpaceCount++;
		}
		p = Tcl_UtfNext(p);
		wordTok->tokWord.end = p;
	    }
	    break;
	    }
	}

	/* calculate end distance value for each tokens */
	if (tok > scnTok) {
	    unsigned int	endDist = 0;
	    ClockScanToken     *prevTok = tok-1;

	    while (prevTok >= scnTok) {
		prevTok->endDistance = endDist;
		if (prevTok->map->type != CTOKT_WORD) {
		    endDist += prevTok->map->minSize;
		} else {
		    endDist += prevTok->tokWord.end - prevTok->tokWord.start;
		}
		prevTok--;
	    }
	}

	/* correct count of real used tokens and free mem if desired
	 * (1 is acceptable delta to prevent memory fragmentation) */
	if (fss->scnTokC > tokCnt + (CLOCK_MIN_TOK_CHAIN_BLOCK_SIZE / 2)) {
	    if ( (tok = (ClockScanToken *)ckrealloc(scnTok, tokCnt * sizeof(*tok))) != NULL ) {
		scnTok = tok;
	    }
	}

	/* now we're ready - assign now to storage (note the threaded race condition) */
	fss->scnTok = scnTok;
	fss->scnTokC = tokCnt;
    }
done:
    Tcl_MutexUnlock(&ClockFmtMutex);

    return fss;
}

/*
 *----------------------------------------------------------------------
 */
int
ClockScan(
    DateInfo *info,	/* Date fields used for parsing & converting */
    Tcl_Obj *strObj,		/* String containing the time to scan */
    ClockFmtScnCmdArgs *opts)	/* Command options */
{
    ClockClientData *dataPtr = (ClockClientData *)opts->clientData;
    ClockFmtScnStorage	*fss;
    ClockScanToken	*tok;
    ClockScanTokenMap	*map;
    const char *p, *x, *end;
    unsigned short int	 flags = 0;
    int ret = TCL_ERROR;

    /* get localized format */
    if (ClockLocalizeFormat(opts) == NULL) {
	return TCL_ERROR;
    }

    if ( !(fss = ClockGetOrParseScanFormat(opts->interp, opts->formatObj))
      || !(tok = fss->scnTok)
    ) {
	return TCL_ERROR;
    }

    /* prepare parsing */

    yyMeridian = MER24;

    p = TclGetString(strObj);
    end = p + strObj->length;
    /* in strict mode - bypass spaces at begin / end only (not between tokens) */
    if (opts->flags & CLF_STRICT) {
	while (p < end && isspace(UCHAR(*p))) {
	    p++;
	}
    }
    yyInput = p;
    /* look ahead to count spaces (bypass it by count length and distances) */
    x = end;
    while (p < end) {
	if (isspace(UCHAR(*p))) {
	    x = ++p; /* after first space in space block */
	    yySpaceCount++;
	    while (p < end && isspace(UCHAR(*p))) {
		p++;
		yySpaceCount++;
	    }
	    continue;
	}
	x = end;
	p++;
    }
    /* ignore more as 1 space at end */
    yySpaceCount -= (end - x);
    end = x;
    /* ignore mandatory spaces used in format */
    yySpaceCount -= fss->scnSpaceCount;
    if (yySpaceCount < 0) {
	yySpaceCount = 0;
    }
    info->dateStart = p = yyInput;
    info->dateEnd = end;

    /* parse string */
    for (; tok->map != NULL; tok++) {
	map = tok->map;
	/* bypass spaces at begin of input before parsing each token */
	if ( !(opts->flags & CLF_STRICT)
	  && ( map->type != CTOKT_SPACE
	    && map->type != CTOKT_WORD
	    && map->type != CTOKT_CHAR )
	) {
	    while (p < end && isspace(UCHAR(*p))) {
		yySpaceCount--;
		p++;
	    }
	}
	yyInput = p;
	/* end of input string */
	if (p >= end) {
	    break;
	}
	switch (map->type)
	{
	case CTOKT_INT:
	case CTOKT_WIDE:
	if (1) {
	    int minLen, size;
	    int sign = 1;
	    if (map->flags & CLF_SIGNED) {
		if (*p == '+') { yyInput = ++p; }
		else
		if (*p == '-') { yyInput = ++p; sign = -1; };
	    }

	    DetermineGreedySearchLen(info, tok, &minLen, &size);

	    if (size < map->minSize) {
		/* missing input -> error */
		if ((map->flags & CLF_OPTIONAL)) {
		    continue;
		}
		goto not_match;
	    }
	    /* string 2 number, put number into info structure by offset */
	    if (map->offs) {
		p = yyInput; x = p + size;
		if (map->type == CTOKT_INT) {
		    if (size <= 10) {
			_str2int_no((int *)(((char *)info) + map->offs),
				p, x, sign);
		    } else {
			if (_str2int((int *)(((char *)info) + map->offs),
				p, x, sign) != TCL_OK) {
			    goto overflow;
			}
		    }
		    p = x;
		} else {
		    if (size <= 18) {
			_str2wideInt_no((Tcl_WideInt *)(((char *)info) + map->offs),
				p, x, sign);
		    } else {
			if (_str2wideInt((Tcl_WideInt *)(((char *)info) + map->offs),
				p, x, sign) != TCL_OK) {
			    goto overflow;
			}
		    }
		    p = x;
		}
		flags = (flags & ~map->clearFlags) | map->flags;
	    }
	}
	break;
	case CTOKT_PARSER:
	    switch (map->parser(opts, info, tok)) {
		case TCL_OK:
		break;
		case TCL_RETURN:
		    if ((map->flags & CLF_OPTIONAL)) {
			yyInput = p;
			continue;
		    }
		    goto not_match;
		break;
		default:
		    goto done;
		break;
	    };
	    /* decrement count for possible spaces in match */
	    while (p < yyInput) {
		if (isspace(UCHAR(*p))) {
		    yySpaceCount--;
		}
		p++;
	    }
	    p = yyInput;
	    flags = (flags & ~map->clearFlags) | map->flags;
	break;
	case CTOKT_SPACE:
	    /* at least one space */
	    if (!isspace(UCHAR(*p))) {
		/* unmatched -> error */
		goto not_match;
	    }
	    /* don't decrement yySpaceCount by regular (first expected space),
	     * already considered above with fss->scnSpaceCount */;
	    p++;
	    while (p < end && isspace(UCHAR(*p))) {
		yySpaceCount--;
		p++;
	    }
	break;
	case CTOKT_WORD:
	    x = FindWordEnd(tok, p, end);
	    if (!x) {
		/* no match -> error */
		goto not_match;
	    }
	    p = x;
	break;
	case CTOKT_CHAR:
	    x = (char *)map->data;
	    if (*x != *p) {
		/* no match -> error */
		goto not_match;
	    }
	    if (isspace(UCHAR(*x))) {
		yySpaceCount--;
	    }
	    p++;
	break;
	}
    }
    /* check end was reached */
    if (p < end) {
	/* in non-strict mode bypass spaces at end of input */
	if ( !(opts->flags & CLF_STRICT) && isspace(UCHAR(*p)) ) {
	    p++;
	    while (p < end && isspace(UCHAR(*p))) {
		p++;
	    }
	}
	/* something after last token - wrong format */
	if (p < end) {
	    goto not_match;
	}
    }
    /* end of string, check only optional tokens at end, otherwise - not match */
    while (tok->map != NULL) {
	if (!(opts->flags & CLF_STRICT) && (tok->map->type == CTOKT_SPACE)) {
	    tok++;
	    if (tok->map == NULL) {
		/* no tokens anymore - trailing spaces are mandatory */
		goto not_match;
	    }
	}
	if (!(tok->map->flags & CLF_OPTIONAL)) {
	    goto not_match;
	}
	tok++;
    }

    /*
     * Invalidate result
     */
    flags |= info->flags;

    /* seconds token (%s) take precedence over all other tokens */
    if ((opts->flags & CLF_EXTENDED) || !(flags & CLF_POSIXSEC)) {
	if (flags & CLF_DATE) {

	    if (!(flags & CLF_JULIANDAY)) {
		info->flags |= CLF_ASSEMBLE_SECONDS|CLF_ASSEMBLE_JULIANDAY;

		/* dd precedence below ddd */
		switch (flags & (CLF_MONTH|CLF_DAYOFYEAR|CLF_DAYOFMONTH)) {
		    case (CLF_DAYOFYEAR|CLF_DAYOFMONTH):
		    /* miss month: ddd over dd (without month) */
		    flags &= ~CLF_DAYOFMONTH;
		    /* fallthrough */
		    case (CLF_DAYOFYEAR):
		    /* ddd over naked weekday */
		    if (!(flags & CLF_ISO8601YEAR)) {
			flags &= ~CLF_ISO8601WEAK;
		    }
		    break;
		    case (CLF_MONTH|CLF_DAYOFYEAR|CLF_DAYOFMONTH):
		    /* both available: mmdd over ddd */
		    case (CLF_MONTH|CLF_DAYOFMONTH):
		    case (CLF_DAYOFMONTH):
		    /* mmdd / dd over naked weekday */
		    if (!(flags & CLF_ISO8601YEAR)) {
			flags &= ~CLF_ISO8601WEAK;
		    }
		    break;
		    /* neither mmdd nor ddd available */
		    case 0:
		    /* but we have day of the week, which can be used */
		    if (flags & CLF_DAYOFWEEK) {
			/* prefer week based calculation of julianday */
			flags |= CLF_ISO8601WEAK;
		    }
		}

		/* YearWeekDay below YearMonthDay */
		if ( (flags & CLF_ISO8601WEAK)
		  && ( (flags & (CLF_YEAR|CLF_DAYOFYEAR)) == (CLF_YEAR|CLF_DAYOFYEAR)
		    || (flags & (CLF_YEAR|CLF_DAYOFMONTH|CLF_MONTH)) == (CLF_YEAR|CLF_DAYOFMONTH|CLF_MONTH)
		  )
		) {
		    /* yy precedence below yyyy */
		    if (!(flags & CLF_ISO8601CENTURY) && (flags & CLF_CENTURY)) {
			/* normally precedence of ISO is higher, but no century - so put it down */
			flags &= ~CLF_ISO8601WEAK;
		    }
		    else
		    /* yymmdd or yyddd over naked weekday */
		    if (!(flags & CLF_ISO8601YEAR)) {
			flags &= ~CLF_ISO8601WEAK;
		    }
		}

		if ( (flags & CLF_YEAR) ) {
		    if (yyYear < 100) {
			if (!(flags & CLF_CENTURY)) {
			    if (yyYear >= dataPtr->yearOfCenturySwitch) {
				yyYear -= 100;
			    }
			    yyYear += dataPtr->currentYearCentury;
			} else {
			    yyYear += info->dateCentury * 100;
			}
		    }
		}
		if ( (flags & (CLF_ISO8601WEAK|CLF_ISO8601YEAR)) ) {
		    if ((flags & (CLF_ISO8601YEAR|CLF_YEAR)) == CLF_YEAR) {
		    	/* for calculations expected iso year */
			info->date.iso8601Year = yyYear;
		    }
		    else
		    if (info->date.iso8601Year < 100) {
			if (!(flags & CLF_ISO8601CENTURY)) {
			    if (info->date.iso8601Year >= dataPtr->yearOfCenturySwitch) {
				info->date.iso8601Year -= 100;
			    }
			    info->date.iso8601Year += dataPtr->currentYearCentury;
			} else {
			    info->date.iso8601Year += info->dateCentury * 100;
			}
		    }
		    if ((flags & (CLF_ISO8601YEAR|CLF_YEAR)) == CLF_ISO8601YEAR) {
		    	/* for calculations expected year (e. g. CLF_ISO8601WEAK not set) */
			yyYear = info->date.iso8601Year;
		    }
		}
	    }
	}

	/* if no time - reset time */
	if (!(flags & (CLF_TIME|CLF_LOCALSEC|CLF_POSIXSEC))) {
	    info->flags |= CLF_ASSEMBLE_SECONDS;
	    yydate.localSeconds = 0;
	}

	if (flags & CLF_TIME) {
	    info->flags |= CLF_ASSEMBLE_SECONDS;
	    yySecondOfDay = ToSeconds(yyHour, yyMinutes,
				yySeconds, yyMeridian);
	} else
	if (!(flags & (CLF_LOCALSEC|CLF_POSIXSEC))) {
	    info->flags |= CLF_ASSEMBLE_SECONDS;
	    yySecondOfDay = yydate.localSeconds % SECONDS_PER_DAY;
	}
    }

    /* tell caller which flags were set */
    info->flags |= flags;

    ret = TCL_OK;
    goto done;

overflow:

    Tcl_SetObjResult(opts->interp, Tcl_NewStringObj("integer value too large to represent",
	-1));
    Tcl_SetErrorCode(opts->interp, "CLOCK", "dateTooLarge", (char *)NULL);
    goto done;

not_match:

  #if 1
    Tcl_SetObjResult(opts->interp, Tcl_NewStringObj("input string does not match supplied format",
	-1));
  #else
	/* to debug where exactly scan breaks */
    Tcl_SetObjResult(opts->interp, Tcl_ObjPrintf(
	"input string \"%s\" does not match supplied format \"%s\","
	" locale \"%s\" - token \"%s\"",
	info->dateStart, HashEntry4FmtScn(fss)->key.string,
        Tcl_GetString(opts->localeObj),
        tok && tok->tokWord.start ? tok->tokWord.start : "NULL"));
  #endif
    Tcl_SetErrorCode(opts->interp, "CLOCK", "badInputString", (char *)NULL);

done:

    return ret;
}

#define FrmResultIsAllocated(dateFmt) \
    (dateFmt->resEnd - dateFmt->resMem > MIN_FMT_RESULT_BLOCK_ALLOC)

static inline int
FrmResultAllocate(
    DateFormat *dateFmt,
    int len)
{
    int needed = dateFmt->output + len - dateFmt->resEnd;
    if (needed >= 0) { /* >= 0 - regards NTS zero */
	int newsize = dateFmt->resEnd - dateFmt->resMem
		    + needed + MIN_FMT_RESULT_BLOCK_ALLOC*2;
	char *newRes;
	/* differentiate between stack and memory */
	if (!FrmResultIsAllocated(dateFmt)) {
	    newRes = (char *)ckalloc(newsize);
	    if (newRes == NULL) {
		return TCL_ERROR;
	    }
	    memcpy(newRes, dateFmt->resMem, dateFmt->output - dateFmt->resMem);
	} else {
	    newRes = (char *)ckrealloc(dateFmt->resMem, newsize);
	    if (newRes == NULL) {
		return TCL_ERROR;
	    }
	}
	dateFmt->output = newRes + (dateFmt->output - dateFmt->resMem);
	dateFmt->resMem = newRes;
	dateFmt->resEnd = newRes + newsize;
    }
    return TCL_OK;
}

static int
ClockFmtToken_HourAMPM_Proc(
    TCL_UNUSED(ClockFmtScnCmdArgs *),
    TCL_UNUSED(DateFormat *),
    TCL_UNUSED(ClockFormatToken *),
    int *val)
{
    *val = ( ( *val + SECONDS_PER_DAY - 3600 ) / 3600 ) % 12 + 1;
    return TCL_OK;
}

static int
ClockFmtToken_AMPM_Proc(
    ClockFmtScnCmdArgs *opts,
    DateFormat *dateFmt,
    ClockFormatToken *tok,
    int *val)
{
    Tcl_Obj *mcObj;
    const char *s;
    Tcl_Size len;

    if (*val < (SECONDS_PER_DAY / 2)) {
	mcObj = ClockMCGet(opts, MCLIT_AM);
    } else {
	mcObj = ClockMCGet(opts, MCLIT_PM);
    }
    if (mcObj == NULL) {
	return TCL_ERROR;
    }
    s = TclGetStringFromObj(mcObj, &len);
    if (FrmResultAllocate(dateFmt, len) != TCL_OK) { return TCL_ERROR; };
    memcpy(dateFmt->output, s, len + 1);
    if (*tok->tokWord.start == 'p') {
	len = Tcl_UtfToUpper(dateFmt->output);
    }
    dateFmt->output += len;

    return TCL_OK;
}

static int
ClockFmtToken_StarDate_Proc(
    TCL_UNUSED(ClockFmtScnCmdArgs *),
    DateFormat *dateFmt,
    TCL_UNUSED(ClockFormatToken *),
    TCL_UNUSED(int *))
{
    int fractYear;
    /* Get day of year, zero based */
    int v = dateFmt->date.dayOfYear - 1;

    /* Convert day of year to a fractional year */
    if (IsGregorianLeapYear(&dateFmt->date)) {
	fractYear = 1000 * v / 366;
    } else {
	fractYear = 1000 * v / 365;
    }

    /* Put together the StarDate as "Stardate %02d%03d.%1d" */
    if (FrmResultAllocate(dateFmt, 30) != TCL_OK) { return TCL_ERROR; };
    memcpy(dateFmt->output, "Stardate ", 9);
    dateFmt->output += 9;
    dateFmt->output = _itoaw(dateFmt->output,
	dateFmt->date.year - RODDENBERRY, '0', 2);
    dateFmt->output = _itoaw(dateFmt->output,
	fractYear, '0', 3);
    *dateFmt->output++ = '.';
    /* be sure positive after decimal point (note: clock-value can be negative) */
    v = dateFmt->date.secondOfDay / ( SECONDS_PER_DAY / 10 );
    if (v < 0) v = 10 + v;
    dateFmt->output = _itoaw(dateFmt->output, v, '0', 1);

    return TCL_OK;
}
static int
ClockFmtToken_WeekOfYear_Proc(
    TCL_UNUSED(ClockFmtScnCmdArgs *),
    DateFormat *dateFmt,
    ClockFormatToken *tok,
    int *val)
{
    int dow = dateFmt->date.dayOfWeek;

    if (*tok->tokWord.start == 'U') {
	if (dow == 7) {
	    dow = 0;
	}
	dow++;
    }
    *val = ( dateFmt->date.dayOfYear - dow + 7 ) / 7;
    return TCL_OK;
}
static int
ClockFmtToken_JDN_Proc(
    TCL_UNUSED(ClockFmtScnCmdArgs *),
    DateFormat *dateFmt,
    ClockFormatToken *tok,
    TCL_UNUSED(int *))
{
    Tcl_WideInt intJD = dateFmt->date.julianDay;
    int fractJD;

    /* Convert to JDN parts (regarding start offset) and time fraction */
    fractJD = dateFmt->date.secondOfDay
	- (int)tok->map->offs; /* 0 for calendar or 43200 for astro JD */
    if (fractJD < 0) {
    	intJD--;
	fractJD += SECONDS_PER_DAY;
    }
    if (fractJD && intJD < 0) { /* avoid jump over 0, by negative JD's */
	intJD++;
	if (intJD == 0) {
	    /* -0.0 / -0.9 has zero integer part, so append "-" extra */
	    if (FrmResultAllocate(dateFmt, 1) != TCL_OK) { return TCL_ERROR; };
	    *dateFmt->output++ = '-';
	}
	/* and inverse seconds of day, -0(75) -> -0.25 as float */
	fractJD = SECONDS_PER_DAY - fractJD;
    }

    /* 21 is max width of (negative) wide-int (rather smaller, but anyway a time fraction below) */
    if (FrmResultAllocate(dateFmt, 21) != TCL_OK) { return TCL_ERROR; };
    dateFmt->output = _witoaw(dateFmt->output, intJD, '0', 1);
    /* simplest cases .0 and .5 */
    if (!fractJD || fractJD == (SECONDS_PER_DAY / 2)) {
	/* point + 0 or 5 */
	if (FrmResultAllocate(dateFmt, 1+1) != TCL_OK) { return TCL_ERROR; };
	*dateFmt->output++ = '.';
	*dateFmt->output++ = !fractJD ? '0' : '5';
	*dateFmt->output = '\0';
	return TCL_OK;
    } else {
	/* wrap the time fraction */
	#define JDN_MAX_PRECISION 8
	#define JDN_MAX_PRECBOUND 100000000 /* 10**JDN_MAX_PRECISION */
	char *p;

	/* to float (part after floating point, + 0.5 to round it up) */
	fractJD = (int)(
	    (double)fractJD * JDN_MAX_PRECBOUND / SECONDS_PER_DAY + 0.5
	);
	/* point + integer (as time fraction after floating point) */
	if (FrmResultAllocate(dateFmt, 1+JDN_MAX_PRECISION) != TCL_OK) { return TCL_ERROR; };
	*dateFmt->output++ = '.';
	p = _itoaw(dateFmt->output, fractJD, '0', JDN_MAX_PRECISION);
	/* remove trailing zero's */
	dateFmt->output++;
	while (p > dateFmt->output && *(p-1) == '0') {p--;}
	*p = '\0';
	dateFmt->output = p;
    }
    return TCL_OK;
}
static int
ClockFmtToken_TimeZone_Proc(
    ClockFmtScnCmdArgs *opts,
    DateFormat *dateFmt,
    ClockFormatToken *tok,
    TCL_UNUSED(int *))
{
    if (*tok->tokWord.start == 'z') {
	int z = dateFmt->date.tzOffset;
	char sign = '+';

	if ( z < 0 ) {
	    z = -z;
	    sign = '-';
	}
	if (FrmResultAllocate(dateFmt, 7) != TCL_OK) { return TCL_ERROR; };
	*dateFmt->output++ = sign;
	dateFmt->output = _itoaw(dateFmt->output, z / 3600, '0', 2);
	z %= 3600;
	dateFmt->output = _itoaw(dateFmt->output, z / 60, '0', 2);
	z %= 60;
	if (z != 0) {
	    dateFmt->output = _itoaw(dateFmt->output, z, '0', 2);
	}
    } else {
	Tcl_Obj * objPtr;
	const char *s; Tcl_Size len;
	/* convert seconds to local seconds to obtain tzName object */
	if (ConvertUTCToLocal(opts->clientData, opts->interp,
		&dateFmt->date, opts->timezoneObj,
		GREGORIAN_CHANGE_DATE) != TCL_OK) {
	    return TCL_ERROR;
	};
	objPtr = dateFmt->date.tzName;
	s = TclGetStringFromObj(objPtr, &len);
	if (FrmResultAllocate(dateFmt, len) != TCL_OK) { return TCL_ERROR; };
	memcpy(dateFmt->output, s, len + 1);
	dateFmt->output += len;
    }
    return TCL_OK;
}

static int
ClockFmtToken_LocaleERA_Proc(
    ClockFmtScnCmdArgs *opts,
    DateFormat *dateFmt,
    TCL_UNUSED(ClockFormatToken *),
    TCL_UNUSED(int *))
{
    Tcl_Obj *mcObj;
    const char *s;
    Tcl_Size len;

    if (dateFmt->date.isBce) {
	mcObj = ClockMCGet(opts, MCLIT_BCE);
    } else {
	mcObj = ClockMCGet(opts, MCLIT_CE);
    }
    if (mcObj == NULL) {
	return TCL_ERROR;
    }
    s = TclGetStringFromObj(mcObj, &len);
    if (FrmResultAllocate(dateFmt, len) != TCL_OK) { return TCL_ERROR; };
    memcpy(dateFmt->output, s, len + 1);
    dateFmt->output += len;

    return TCL_OK;
}

static int
ClockFmtToken_LocaleERAYear_Proc(
    ClockFmtScnCmdArgs *opts,
    DateFormat *dateFmt,
    ClockFormatToken *tok,
    int *val)
{
    Tcl_Size rowc;
    Tcl_Obj **rowv;

    if (dateFmt->localeEra == NULL) {
	Tcl_Obj *mcObj = ClockMCGet(opts, MCLIT_LOCALE_ERAS);
	if (mcObj == NULL) {
	    return TCL_ERROR;
	}
	if (TclListObjGetElements(opts->interp, mcObj, &rowc, &rowv) != TCL_OK) {
	    return TCL_ERROR;
	}
	if (rowc != 0) {
	    dateFmt->localeEra = LookupLastTransition(opts->interp,
		dateFmt->date.localSeconds, rowc, rowv, NULL);
	}
	if (dateFmt->localeEra == NULL) {
	    dateFmt->localeEra = (Tcl_Obj*)1;
	}
    }

    /* if no LOCALE_ERAS in catalog or era not found */
    if (dateFmt->localeEra == (Tcl_Obj*)1) {
	if (FrmResultAllocate(dateFmt, 11) != TCL_OK) { return TCL_ERROR; };
	if (*tok->tokWord.start == 'C') { /* %EC */
	    *val = dateFmt->date.year / 100;
	    dateFmt->output = _itoaw(dateFmt->output,
		*val, '0', 2);
	} else {			  /* %Ey */
	    *val = dateFmt->date.year % 100;
	    dateFmt->output = _itoaw(dateFmt->output,
		*val, '0', 2);
	}
    } else {
	Tcl_Obj *objPtr;
	const char *s;
	Tcl_Size len;
	if (*tok->tokWord.start == 'C') { /* %EC */
	    if (Tcl_ListObjIndex(opts->interp, dateFmt->localeEra, 1,
			&objPtr) != TCL_OK ) {
		return TCL_ERROR;
	    }
	} else {			  /* %Ey */
	    if (Tcl_ListObjIndex(opts->interp, dateFmt->localeEra, 2,
			&objPtr) != TCL_OK ) {
		return TCL_ERROR;
	    }
	    if (Tcl_GetIntFromObj(opts->interp, objPtr, val) != TCL_OK) {
		return TCL_ERROR;
	    }
	    *val = dateFmt->date.year - *val;
	    /* if year in locale numerals */
	    if (*val >= 0 && *val < 100) {
		/* year as integer */
		Tcl_Obj * mcObj = ClockMCGet(opts, MCLIT_LOCALE_NUMERALS);
		if (mcObj == NULL) {
		    return TCL_ERROR;
		}
		if (Tcl_ListObjIndex(opts->interp, mcObj, *val, &objPtr) != TCL_OK) {
		    return TCL_ERROR;
		}
	    } else {
		/* year as integer */
		if (FrmResultAllocate(dateFmt, 11) != TCL_OK) { return TCL_ERROR; };
		dateFmt->output = _itoaw(dateFmt->output,
		    *val, '0', 2);
		return TCL_OK;
	    }
	}
	s = TclGetStringFromObj(objPtr, &len);
	if (FrmResultAllocate(dateFmt, len) != TCL_OK) { return TCL_ERROR; };
	memcpy(dateFmt->output, s, len + 1);
	dateFmt->output += len;
    }
    return TCL_OK;
}


static const char *FmtSTokenMapIndex =
    "demNbByYCHMSIklpaAuwUVzgGjJsntQ";
static ClockFormatTokenMap FmtSTokenMap[] = {
    /* %d */
    {CTOKT_INT, "0", 2, 0, 0, 0, offsetof(DateFormat, date.dayOfMonth), NULL, NULL},
    /* %e */
    {CTOKT_INT, " ", 2, 0, 0, 0, offsetof(DateFormat, date.dayOfMonth), NULL, NULL},
    /* %m */
    {CTOKT_INT, "0", 2, 0, 0, 0, offsetof(DateFormat, date.month), NULL, NULL},
    /* %N */
    {CTOKT_INT, " ", 2, 0, 0, 0, offsetof(DateFormat, date.month), NULL, NULL},
    /* %b %h */
    {CTOKT_INT, NULL, 0, CLFMT_LOCALE_INDX | CLFMT_DECR, 0, 12, offsetof(DateFormat, date.month),
	NULL, (void *)MCLIT_MONTHS_ABBREV},
    /* %B */
    {CTOKT_INT, NULL, 0, CLFMT_LOCALE_INDX | CLFMT_DECR, 0, 12, offsetof(DateFormat, date.month),
	NULL, (void *)MCLIT_MONTHS_FULL},
    /* %y */
    {CTOKT_INT, "0", 2, 0, 0, 100, offsetof(DateFormat, date.year), NULL, NULL},
    /* %Y */
    {CTOKT_INT, "0", 4, 0, 0, 0, offsetof(DateFormat, date.year), NULL, NULL},
    /* %C */
    {CTOKT_INT, "0", 2, 0, 100, 0, offsetof(DateFormat, date.year), NULL, NULL},
    /* %H */
    {CTOKT_INT, "0", 2, 0, 3600, 24, offsetof(DateFormat, date.secondOfDay), NULL, NULL},
    /* %M */
    {CTOKT_INT, "0", 2, 0, 60, 60, offsetof(DateFormat, date.secondOfDay), NULL, NULL},
    /* %S */
    {CTOKT_INT, "0", 2, 0, 0, 60, offsetof(DateFormat, date.secondOfDay), NULL, NULL},
    /* %I */
    {CTOKT_INT, "0", 2, CLFMT_CALC, 0, 0, offsetof(DateFormat, date.secondOfDay),
	ClockFmtToken_HourAMPM_Proc, NULL},
    /* %k */
    {CTOKT_INT, " ", 2, 0, 3600, 24, offsetof(DateFormat, date.secondOfDay), NULL, NULL},
    /* %l */
    {CTOKT_INT, " ", 2, CLFMT_CALC, 0, 0, offsetof(DateFormat, date.secondOfDay),
	ClockFmtToken_HourAMPM_Proc, NULL},
    /* %p %P */
    {CTOKT_INT, NULL, 0, 0, 0, 0, offsetof(DateFormat, date.secondOfDay),
	ClockFmtToken_AMPM_Proc, NULL},
    /* %a */
    {CTOKT_INT, NULL, 0, CLFMT_LOCALE_INDX, 0, 7, offsetof(DateFormat, date.dayOfWeek),
	NULL, (void *)MCLIT_DAYS_OF_WEEK_ABBREV},
    /* %A */
    {CTOKT_INT, NULL, 0, CLFMT_LOCALE_INDX, 0, 7, offsetof(DateFormat, date.dayOfWeek),
	NULL, (void *)MCLIT_DAYS_OF_WEEK_FULL},
    /* %u */
    {CTOKT_INT, " ", 1, 0, 0, 0, offsetof(DateFormat, date.dayOfWeek), NULL, NULL},
    /* %w */
    {CTOKT_INT, " ", 1, 0, 0, 7, offsetof(DateFormat, date.dayOfWeek), NULL, NULL},
    /* %U %W */
    {CTOKT_INT, "0", 2, CLFMT_CALC, 0, 0, offsetof(DateFormat, date.dayOfYear),
	ClockFmtToken_WeekOfYear_Proc, NULL},
    /* %V */
    {CTOKT_INT, "0", 2, 0, 0, 0, offsetof(DateFormat, date.iso8601Week), NULL, NULL},
    /* %z %Z */
    {CFMTT_PROC, NULL, 0, 0, 0, 0, 0,
	ClockFmtToken_TimeZone_Proc, NULL},
    /* %g */
    {CTOKT_INT, "0", 2, 0, 0, 100, offsetof(DateFormat, date.iso8601Year), NULL, NULL},
    /* %G */
    {CTOKT_INT, "0", 4, 0, 0, 0, offsetof(DateFormat, date.iso8601Year), NULL, NULL},
    /* %j */
    {CTOKT_INT, "0", 3, 0, 0, 0, offsetof(DateFormat, date.dayOfYear), NULL, NULL},
    /* %J */
    {CTOKT_WIDE, "0", 7, 0, 0, 0, offsetof(DateFormat, date.julianDay), NULL, NULL},
    /* %s */
    {CTOKT_WIDE, "0", 1, 0, 0, 0, offsetof(DateFormat, date.seconds), NULL, NULL},
    /* %n */
    {CTOKT_CHAR, "\n", 0, 0, 0, 0, 0, NULL, NULL},
    /* %t */
    {CTOKT_CHAR, "\t", 0, 0, 0, 0, 0, NULL, NULL},
    /* %Q */
    {CFMTT_PROC, NULL, 0, 0, 0, 0, 0,
	ClockFmtToken_StarDate_Proc, NULL},
};
static const char *FmtSTokenMapAliasIndex[2] = {
    "hPWZ",
    "bpUz"
};

static const char *FmtETokenMapIndex =
    "EJjys";
static ClockFormatTokenMap FmtETokenMap[] = {
    /* %EE */
    {CFMTT_PROC, NULL, 0, 0, 0, 0, 0,
	ClockFmtToken_LocaleERA_Proc, NULL},
    /* %EJ */
    {CFMTT_PROC, NULL, 0, 0, 0, 0, 0, /* calendar JDN starts at midnight */
	ClockFmtToken_JDN_Proc, NULL},
    /* %Ej */
    {CFMTT_PROC, NULL, 0, 0, 0, 0, (SECONDS_PER_DAY/2), /* astro JDN starts at noon */
	ClockFmtToken_JDN_Proc, NULL},
    /* %Ey %EC */
    {CTOKT_INT, NULL, 0, 0, 0, 0, offsetof(DateFormat, date.year),
	ClockFmtToken_LocaleERAYear_Proc, NULL},
    /* %Es */
    {CTOKT_WIDE, "0", 1, 0, 0, 0, offsetof(DateFormat, date.localSeconds), NULL, NULL},
};
static const char *FmtETokenMapAliasIndex[2] = {
    "C",
    "y"
};

static const char *FmtOTokenMapIndex =
    "dmyHIMSuw";
static ClockFormatTokenMap FmtOTokenMap[] = {
    /* %Od %Oe */
    {CTOKT_INT, NULL, 0, CLFMT_LOCALE_INDX, 0, 100, offsetof(DateFormat, date.dayOfMonth),
	NULL, (void *)MCLIT_LOCALE_NUMERALS},
    /* %Om */
    {CTOKT_INT, NULL, 0, CLFMT_LOCALE_INDX, 0, 100, offsetof(DateFormat, date.month),
	NULL, (void *)MCLIT_LOCALE_NUMERALS},
    /* %Oy */
    {CTOKT_INT, NULL, 0, CLFMT_LOCALE_INDX, 0, 100, offsetof(DateFormat, date.year),
	NULL, (void *)MCLIT_LOCALE_NUMERALS},
    /* %OH %Ok */
    {CTOKT_INT, NULL, 0, CLFMT_LOCALE_INDX, 3600, 24, offsetof(DateFormat, date.secondOfDay),
	NULL, (void *)MCLIT_LOCALE_NUMERALS},
    /* %OI %Ol */
    {CTOKT_INT, NULL, 0, CLFMT_CALC | CLFMT_LOCALE_INDX, 0, 0, offsetof(DateFormat, date.secondOfDay),
	ClockFmtToken_HourAMPM_Proc, (void *)MCLIT_LOCALE_NUMERALS},
    /* %OM */
    {CTOKT_INT, NULL, 0, CLFMT_LOCALE_INDX, 60, 60, offsetof(DateFormat, date.secondOfDay),
	NULL, (void *)MCLIT_LOCALE_NUMERALS},
    /* %OS */
    {CTOKT_INT, NULL, 0, CLFMT_LOCALE_INDX, 0, 60, offsetof(DateFormat, date.secondOfDay),
	NULL, (void *)MCLIT_LOCALE_NUMERALS},
    /* %Ou */
    {CTOKT_INT, NULL, 0, CLFMT_LOCALE_INDX, 0, 100, offsetof(DateFormat, date.dayOfWeek),
	NULL, (void *)MCLIT_LOCALE_NUMERALS},
    /* %Ow */
    {CTOKT_INT, NULL, 0, CLFMT_LOCALE_INDX, 0, 7, offsetof(DateFormat, date.dayOfWeek),
	NULL, (void *)MCLIT_LOCALE_NUMERALS},
};
static const char *FmtOTokenMapAliasIndex[2] = {
    "ekl",
    "dHI"
};

static ClockFormatTokenMap FmtWordTokenMap = {
    CTOKT_WORD, NULL, 0, 0, 0, 0, 0, NULL, NULL
};

/*
 *----------------------------------------------------------------------
 */
ClockFmtScnStorage *
ClockGetOrParseFmtFormat(
    Tcl_Interp *interp,		/* Tcl interpreter */
    Tcl_Obj    *formatObj)	/* Format container */
{
    ClockFmtScnStorage *fss;

    fss = Tcl_GetClockFrmScnFromObj(interp, formatObj);
    if (fss == NULL) {
	return NULL;
    }

    /* if format (fmtTok) already tokenized */
    if (fss->fmtTok != NULL) {
	return fss;
    }

    Tcl_MutexLock(&ClockFmtMutex);

    /* first time formatting - tokenize format */
    if (fss->fmtTok == NULL) {
	ClockFormatToken *tok, *fmtTok;
	unsigned int tokCnt;
	const char *p, *e, *cp;

	e = p = HashEntry4FmtScn(fss)->key.string;
	e += strlen(p);

	/* estimate token count by % char and format length */
	fss->fmtTokC = EstimateTokenCount(p, e);

	fmtTok = tok = (ClockFormatToken *)ckalloc(sizeof(*tok) * fss->fmtTokC);
	memset(tok, 0, sizeof(*(tok)));
	tokCnt = 1;
	while (p < e) {
	    switch (*p) {
	    case '%':
	    if (1) {
		ClockFormatTokenMap * fmtMap = FmtSTokenMap;
		const char *mapIndex =	FmtSTokenMapIndex,
			  **aliasIndex = FmtSTokenMapAliasIndex;
		if (p+1 >= e) {
		    goto word_tok;
		}
		p++;
		/* try to find modifier: */
		switch (*p) {
		case '%':
		    /* begin new word token - don't join with previous word token,
		     * because current mapping should be "...%%..." -> "...%..." */
		    tok->map = &FmtWordTokenMap;
		    tok->tokWord.start = p;
		    tok->tokWord.end = p+1;
		    AllocTokenInChain(tok, fmtTok, fss->fmtTokC, ClockFormatToken *); tokCnt++;
		    p++;
		    continue;
		break;
		case 'E':
		    fmtMap = FmtETokenMap,
		    mapIndex =	FmtETokenMapIndex,
		    aliasIndex = FmtETokenMapAliasIndex;
		    p++;
		break;
		case 'O':
		    fmtMap = FmtOTokenMap,
		    mapIndex = FmtOTokenMapIndex,
		    aliasIndex = FmtOTokenMapAliasIndex;
		    p++;
		break;
		}
		/* search direct index */
		cp = strchr(mapIndex, *p);
		if (!cp || *cp == '\0') {
		    /* search wrapper index (multiple chars for same token) */
		    cp = strchr(aliasIndex[0], *p);
		    if (!cp || *cp == '\0') {
			p--; if (fmtMap != FmtSTokenMap) p--;
			goto word_tok;
		    }
		    cp = strchr(mapIndex, aliasIndex[1][cp - aliasIndex[0]]);
		    if (!cp || *cp == '\0') { /* unexpected, but ... */
		    #ifdef DEBUG
			Tcl_Panic("token \"%c\" has no map in wrapper resolver", *p);
		    #endif
			p--; if (fmtMap != FmtSTokenMap) p--;
			goto word_tok;
		    }
		}
		tok->map = &fmtMap[cp - mapIndex];
		tok->tokWord.start = p;
		/* next token */
		AllocTokenInChain(tok, fmtTok, fss->fmtTokC, ClockFormatToken *); tokCnt++;
		p++;
		continue;
	    }
	    break;
	    default:
word_tok:
	    if (1) {
		ClockFormatToken *wordTok = tok;
		if (tok > fmtTok && (tok-1)->map == &FmtWordTokenMap) {
		    wordTok = tok-1;
		}
		if (wordTok == tok) {
		    wordTok->tokWord.start = p;
		    wordTok->map = &FmtWordTokenMap;
		    AllocTokenInChain(tok, fmtTok, fss->fmtTokC, ClockFormatToken *); tokCnt++;
		}
		p = Tcl_UtfNext(p);
		wordTok->tokWord.end = p;
	    }
	    break;
	    }
	}

	/* correct count of real used tokens and free mem if desired
	 * (1 is acceptable delta to prevent memory fragmentation) */
	if (fss->fmtTokC > tokCnt + (CLOCK_MIN_TOK_CHAIN_BLOCK_SIZE / 2)) {
	    if ( (tok = (ClockFormatToken *)ckrealloc(fmtTok, tokCnt * sizeof(*tok))) != NULL ) {
		fmtTok = tok;
	    }
	}

	/* now we're ready - assign now to storage (note the threaded race condition) */
	fss->fmtTok = fmtTok;
	fss->fmtTokC = tokCnt;
    }
done:
    Tcl_MutexUnlock(&ClockFmtMutex);

    return fss;
}

/*
 *----------------------------------------------------------------------
 */
int
ClockFormat(
    DateFormat *dateFmt, /* Date fields used for parsing & converting */
    ClockFmtScnCmdArgs *opts)	  /* Command options */
{
    ClockFmtScnStorage	*fss;
    ClockFormatToken	*tok;
    ClockFormatTokenMap *map;
    char resMem[MIN_FMT_RESULT_BLOCK_ALLOC];

    /* get localized format */
    if (ClockLocalizeFormat(opts) == NULL) {
	return TCL_ERROR;
    }

    if ( !(fss = ClockGetOrParseFmtFormat(opts->interp, opts->formatObj))
      || !(tok = fss->fmtTok)
    ) {
	return TCL_ERROR;
    }

    /* result container object */
    dateFmt->resMem = resMem;
    dateFmt->resEnd = dateFmt->resMem + sizeof(resMem);
    if (fss->fmtMinAlloc > sizeof(resMem)) {
	dateFmt->resMem = (char *)ckalloc(fss->fmtMinAlloc);
	dateFmt->resEnd = dateFmt->resMem + fss->fmtMinAlloc;
	if (dateFmt->resMem == NULL) {
	    return TCL_ERROR;
	}
    }
    dateFmt->output = dateFmt->resMem;
    *dateFmt->output = '\0';

    /* do format each token */
    for (; tok->map != NULL; tok++) {
	map = tok->map;
	switch (map->type)
	{
	case CTOKT_INT:
	if (1) {
	    int val = (int)*(int *)(((char *)dateFmt) + map->offs);
	    if (map->fmtproc == NULL) {
		if (map->flags & CLFMT_DECR) {
		    val--;
		}
		if (map->flags & CLFMT_INCR) {
		    val++;
		}
		if (map->divider) {
		    val /= map->divider;
		}
		if (map->divmod) {
		    val %= map->divmod;
		}
	    } else {
		if (map->fmtproc(opts, dateFmt, tok, &val) != TCL_OK) {
		    goto done;
		}
		/* if not calculate only (output inside fmtproc) */
		if (!(map->flags & CLFMT_CALC)) {
		    continue;
		}
	    }
	    if (!(map->flags & CLFMT_LOCALE_INDX)) {
		if (FrmResultAllocate(dateFmt, 11) != TCL_OK) { goto error; };
		if (map->width) {
		    dateFmt->output = _itoaw(dateFmt->output, val, *map->tostr, map->width);
		} else {
		    dateFmt->output += sprintf(dateFmt->output, map->tostr, val);
		}
	    } else {
		const char *s;
		Tcl_Obj * mcObj = ClockMCGet(opts, PTR2INT(map->data) /* mcKey */);
		if (mcObj == NULL) {
		    goto error;
		}
		if ( Tcl_ListObjIndex(opts->interp, mcObj, val, &mcObj) != TCL_OK
		  || mcObj == NULL
		) {
		    goto error;
		}
		s = TclGetString(mcObj);
		if (FrmResultAllocate(dateFmt, mcObj->length) != TCL_OK) { goto error; };
		memcpy(dateFmt->output, s, mcObj->length + 1);
		dateFmt->output += mcObj->length;
	    }
	}
	break;
	case CTOKT_WIDE:
	if (1) {
	    Tcl_WideInt val = *(Tcl_WideInt *)(((char *)dateFmt) + map->offs);
	    if (FrmResultAllocate(dateFmt, 21) != TCL_OK) { goto error; };
	    if (map->width) {
		dateFmt->output = _witoaw(dateFmt->output, val, *map->tostr, map->width);
	    } else {
		dateFmt->output += sprintf(dateFmt->output, map->tostr, val);
	    }
	}
	break;
	case CTOKT_CHAR:
	    if (FrmResultAllocate(dateFmt, 1) != TCL_OK) { goto error; };
	    *dateFmt->output++ = *map->tostr;
	break;
	case CFMTT_PROC:
	    if (map->fmtproc(opts, dateFmt, tok, NULL) != TCL_OK) {
		goto error;
	    };
	break;
	case CTOKT_WORD:
	    if (1) {
		Tcl_Size len = tok->tokWord.end - tok->tokWord.start;
		if (FrmResultAllocate(dateFmt, len) != TCL_OK) { goto error; };
		if (len == 1) {
		    *dateFmt->output++ = *tok->tokWord.start;
		} else {
		    memcpy(dateFmt->output, tok->tokWord.start, len);
		    dateFmt->output += len;
		}
	    }
	break;
	}
    }

    goto done;

error:

    if (dateFmt->resMem != resMem) {
	ckfree(dateFmt->resMem);
    }
    dateFmt->resMem = NULL;

done:

    if (dateFmt->resMem) {
	size_t size;
	Tcl_Obj *result;
	TclNewObj(result);
	result->length = dateFmt->output - dateFmt->resMem;
	size = result->length+1;
	if (dateFmt->resMem == resMem) {
	    result->bytes = (char *)ckalloc(size);
	    if (result->bytes == NULL) {
		return TCL_ERROR;
	    }
	    memcpy(result->bytes, dateFmt->resMem, size);
	} else if ((dateFmt->resEnd - dateFmt->resMem) / size > MAX_FMT_RESULT_THRESHOLD) {
	    result->bytes = (char *)ckrealloc(dateFmt->resMem, size);
	    if (result->bytes == NULL) {
		result->bytes = dateFmt->resMem;
	    }
	} else {
	    result->bytes = dateFmt->resMem;
	}
	/* save last used buffer length */
	if ( dateFmt->resMem != resMem
	  && fss->fmtMinAlloc < size + MIN_FMT_RESULT_BLOCK_DELTA
	) {
	    fss->fmtMinAlloc = size + MIN_FMT_RESULT_BLOCK_DELTA;
	}
	result->bytes[result->length] = '\0';
	Tcl_SetObjResult(opts->interp, result);
	return TCL_OK;
    }

    return TCL_ERROR;
}


void
ClockFrmScnClearCaches(void)
{
    Tcl_MutexLock(&ClockFmtMutex);
    /* clear caches ... */
    Tcl_MutexUnlock(&ClockFmtMutex);
}

static void
ClockFrmScnFinalize(
    TCL_UNUSED(void *))
{
    Tcl_MutexLock(&ClockFmtMutex);
#if CLOCK_FMT_SCN_STORAGE_GC_SIZE > 0
    /* clear GC */
    ClockFmtScnStorage_GC.stackPtr = NULL;
    ClockFmtScnStorage_GC.stackBound = NULL;
    ClockFmtScnStorage_GC.count = 0;
#endif
    if (initialized) {
	Tcl_DeleteHashTable(&FmtScnHashTable);
	initialized = 0;
    }
    Tcl_MutexUnlock(&ClockFmtMutex);
    Tcl_MutexFinalize(&ClockFmtMutex);
}
/*
 * Local Variables:
 * mode: c
 * c-basic-offset: 4
 * fill-column: 78
 * End:
 */