Tcl Source Code

2006-04-25  Don Porter  <[email protected]>

	* doc/DoubleObj.3:	More doc updates for TIP 237.
	* doc/scan.n:

	* generic/tclScan.c:	[scan $s %u] is documented to accept only
	* tests/scan.test:	decimal formatted integers.  Fixed code to
	match.

2006-04-19  Kevin B. Kenny  <[email protected]>

	* generic/tclStrToD.c: Added code to support the "middle endian"
	floating point format used in the Nokia N770's software-based
	floating point.  Thanks to Bruce Johnson for reporting this bug,
	originally on http://wiki.tcl.tk/15408.
	* library/clock.tcl: Fixed a bug with Daylight Saving Time and

'\"
'\" Copyright (c) 1996-1997 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: DoubleObj.3,v 1.4 2006/04/25 17:15:25 dgp Exp $
'\" 
.so man.macros
.TH Tcl_DoubleObj 3 8.0 Tcl "Tcl Library Procedures"
.BS
.SH NAME
Tcl_NewDoubleObj, Tcl_SetDoubleObj, Tcl_GetDoubleFromObj \- manipulate Tcl objects as floating-point values
.SH SYNOPSIS
.nf
\fB#include <tcl.h>\fR
.sp
Tcl_Obj *
\fBTcl_NewDoubleObj\fR(\fIdoubleValue\fR)
.sp
\fBTcl_SetDoubleObj\fR(\fIobjPtr, doubleValue\fR)
.sp
int
\fBTcl_GetDoubleFromObj\fR(\fIinterp, objPtr, doublePtr\fR)
.SH ARGUMENTS
.AS Tcl_Interp doubleValue in/out
.AP double doubleValue in
A double-precision floating-point value used to initialize or set a Tcl object.
.AP Tcl_Obj *objPtr in/out
For \fBTcl_SetDoubleObj\fR, this points to the object in which to store a
double value.
For \fBTcl_GetDoubleFromObj\fR, this refers to the object
from which to retrieve a double value. 


.AP Tcl_Interp *interp in/out

When non-NULL, an error message is left here when double value retrieval fails.

.AP double *doublePtr out
Points to place to store the double value obtained from \fIobjPtr\fR.

.BE

.SH DESCRIPTION
.PP
These procedures are used to create, modify, and read Tcl objects that





hold double-precision floating-point values.
.PP
\fBTcl_NewDoubleObj\fR creates and returns a new Tcl object initialized to



the double value \fIdoubleValue\fR.  The returned Tcl object is unshared.
.PP
\fBTcl_SetDoubleObj\fR sets the value of an existing Tcl object pointed to
by \fIobjPtr\fR to the double value \fIdoubleValue\fR.  The \fIobjPtr\fR
argument must point to an unshared Tcl object.  Any attempt to set the value
of a shared Tcl object violates Tcl's copy-on-write policy.  Any existing
string representation or internal representation in the unshared Tcl object
will be freed as a consequence of setting the new value.
.PP
\fBTcl_GetDoubleFromObj\fR attempts to retreive a double value from the
Tcl object \fIobjPtr\fR.  If the attempt succeeds, then \fBTCL_OK\fR is
returned, and the double value is written to the storage pointed to by

\fIdoublePtr\fR.  If the attempt fails, then \fBTCL_ERROR\fR is returned,

and if \fIinterp\fR is non-NULL, an error message is left in \fIinterp\fR.

The \fBTcl_ObjType\fR of \fIobjPtr\fR may be changed to make subsequent


calls to \fBTcl_GetDoubleFromObj\fR more efficient. 
'\" TODO: add discussion of treatment of NaN value
.SH "SEE ALSO"
Tcl_NewObj, Tcl_DecrRefCount, Tcl_IncrRefCount, Tcl_GetObjResult

.SH KEYWORDS
double, double object, double type, internal representation, object, object type, string representation

'\"
'\" Copyright (c) 1993 The Regents of the University of California.
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
'\" Copyright (c) 2000 Scriptics Corporation.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: scan.n,v 1.16 2006/04/25 17:15:25 dgp Exp $
'\" 
.so man.macros
.TH scan n 8.4 Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
scan \- Parse string using conversion specifiers in the style of sscanf
.SH SYNOPSIS
\fBscan \fIstring format \fR?\fIvarName varName ...\fR?
.BE

.SH INTRODUCTION
.PP
This command parses substrings from an input string in a fashion similar
to the ANSI C \fBsscanf\fR procedure and returns a count of the number of
conversions performed, or -1 if the end of the input string is reached
before any conversions have been performed.  \fIString\fR gives the input
to be parsed and \fIformat\fR indicates how to parse it, using \fB%\fR
conversion specifiers as in \fBsscanf\fR.  Each \fIvarName\fR gives the
name of a variable; when a substring is scanned from \fIstring\fR that
matches a conversion specifier, the substring is assigned to the
corresponding variable.
If no \fIvarName\fR variables are specified, then \fBscan\fR works in an
inline manner, returning the data that would otherwise be stored in the
variables as a list.  In the inline case, an empty string is returned when
the end of the input string is reached before any conversions have been
performed.
.SH "DETAILS ON SCANNING"
.PP
\fBScan\fR operates by scanning \fIstring\fR and \fIformat\fR together.
If the next character in \fIformat\fR is a blank or tab then it
matches any number of white space characters in \fIstring\fR (including
zero).
Otherwise, if it isn't a \fB%\fR character then it 
must match the next character of \fIstring\fR.
When a \fB%\fR is encountered in \fIformat\fR, it indicates
the start of a conversion specifier.
A conversion specifier contains up to four fields after the \fB%\fR:
a XPG3 position specifier (or a \fB*\fR to indicate the converted
value is to be discarded instead of assigned to any variable); a number
indicating a maximum substring width; a size modifier; and a
conversion character.
All of these fields are optional except for the conversion character.
The fields that are present must appear in the order given above.
.PP
When \fBscan\fR finds a conversion specifier in \fIformat\fR, it
first skips any white-space characters in \fIstring\fR (unless the
conversion character is \fB[\fR or \fBc\fR).
Then it converts the next input characters according to the 
conversion specifier and stores the result in the variable given
by the next argument to \fBscan\fR.
.PP
If the \fB%\fR is followed by a decimal number and a \fB$\fR, as in
``\fB%2$d\fR'', then the variable to use is not taken from the next
sequential argument.  Instead, it is taken from the argument indicated
by the number, where 1 corresponds to the first \fIvarName\fR.  If
there are any positional specifiers in \fIformat\fR then all of the
specifiers must be positional.  Every \fIvarName\fR on the argument
list must correspond to exactly one conversion specifier or an error
is generated, or in the inline case, any position can be specified
at most once and the empty positions will be filled in with empty strings.
.PP
.VS 8.5
The size modifier field is used only when scanning a substring into
one of Tcl's integer values.  The size modifier field dictates the
integer range acceptable to be stored in a variable, or, for the inline
case, in a position in the result list.
The syntactically valid values for the size modifier are \fBh\fR, \fBL\fR,
\fBl\fR, and \fBll\fR.  The \fBh\fR size modifier value is equivalent
to the absence of a size modifier in the the conversion specifier.
Either one indicates the integer range to be stored is limited to
the same range produced by the \fBint()\fR function of the \fBexpr\fR
command.  The \fBL\fR size modifier is equivalent to the \fBl\fR size
modifer.  Either one indicates the integer range to be stored is
limited to the same range produced by the \fBwide()\fR function of
the \fBexpr\fR command.  The \fBll\fR size modifier indicates that
the integer range ro be stored is unlimited.
.VE 8.5
.PP
The following conversion characters are supported:
.TP 10
\fBd\fR
The input substring must be a decimal integer.
It is read in and the integer value is stored in the variable,
truncated as required by the size modifier value.


.TP 10
\fBo\fR
The input substring must be an octal integer. It is read in and the 
integer value is stored in the variable,
truncated as required by the size modifier value.






.TP 10
\fBx\fR
The input substring must be a hexadecimal integer.
It is read in and the integer value is stored in the variable,
truncated as required by the size modifier value.






.TP 10
\fBu\fR
The input substring must be a decimal integer.
The integer value is truncated as required by the size modifier
value, and the corresponding unsigned value for that truncated
range is computed and stored in the variable as a decimal string.
The conversion makes no sense without refernce to a truncation range,
so the size modifer \fBll\fR is not permitted in combination

with conversion character \fBu\fR.
.TP 10
\fBi\fR 
The input substring must be an integer.  The base (i.e. decimal, octal, or
hexadecimal) is determined in the same fashion as described in
\fBexpr\fR.  The integer value is stored in the variable,
truncated as required by the size modifier value.


.TP 10
\fBc\fR
A single character is read in and its Unicode value is stored in 
the variable as an integer value.
Initial white space is not skipped in this case, so the input
substring may be a white-space character.



.TP 10
\fBs\fR
The input substring consists of all the characters up to the next 
white-space character; the characters are copied to the variable.
.TP 10
\fBe\fR or \fBf\fR or \fBg\fR
The input substring must be a floating-point number consisting 
of an optional sign, a string of decimal digits possibly
containing a decimal point, and an optional exponent consisting 
of an \fBe\fR or \fBE\fR followed by an optional sign and a string of 
decimal digits.
It is read in and stored in the variable as a floating-point value.
.TP 10
\fB[\fIchars\fB]\fR
The input substring consists of one or more characters in \fIchars\fR.
The matching string is stored in the variable.
If the first character between the brackets is a \fB]\fR then
it is treated as part of \fIchars\fR rather than the closing
bracket for the set.
If \fIchars\fR
contains a sequence of the form \fIa\fB\-\fIb\fR then any
character between \fIa\fR and \fIb\fR (inclusive) will match.
If the first or last character between the brackets is a \fB\-\fR, then
it is treated as part of \fIchars\fR rather than indicating a range.
.TP 10
\fB[^\fIchars\fB]\fR
The input substring consists of one or more characters not in \fIchars\fR.
The matching string is stored in the variable.
If the character immediately following the \fB^\fR is a \fB]\fR then it is 
treated as part of the set rather than the closing bracket for 
the set.
If \fIchars\fR
contains a sequence of the form \fIa\fB\-\fIb\fR then any
character between \fIa\fR and \fIb\fR (inclusive) will be excluded
from the set.
If the first or last character between the brackets is a \fB\-\fR, then
it is treated as part of \fIchars\fR rather than indicating a ranvaluege.
.TP 10
\fBn\fR
No input is consumed from the input string.  Instead, the total number
of characters scanned from the input string so far is stored in the variable.
.LP
The number of characters read from the input for a conversion is the
largest number that makes sense for that particular conversion (e.g.
as many decimal digits as possible for \fB%d\fR, as 
many octal digits as possible for \fB%o\fR, and so on).
The input substring for a given conversion terminates either when a
white-space character is encountered or when the maximum substring 
width has been reached, whichever comes first.
If a \fB*\fR is present in the conversion specifier 
then no variable is assigned and the next scan argument is not consumed.
.SH "DIFFERENCES FROM ANSI SSCANF"
.PP
The behavior of the \fBscan\fR command is the same as the behavior of
the ANSI C \fBsscanf\fR procedure except for the following differences:
.IP [1]
\fB%p\fR conversion specifier is not supported.
.IP [2]
For \fB%c\fR conversions a single character value is
converted to a decimal string, which is then assigned to the
corresponding \fIvarName\fR;
no substring width may be specified for this conversion.
.IP [3]
The \fBh\fR modifier is always ignored and the \fBl\fR and \fBL\fR
modifiers are ignored when converting real values (i.e. type
\fBdouble\fR is used for the internal representation).  The \fBll\fR
modifier has no \fBsscanf\fR counterpart.
.IP [4]
If the end of the input string is reached before any conversions have been
performed and no variables are given, an empty string is returned.
.SH EXAMPLES
Parse a simple color specification of the form \fI#RRGGBB\fR using
hexadecimal conversions with substring sizes:
.CS
set string "#08D03F"
\fBscan\fR $string "#%2x%2x%2x" r g b
.CE
.PP
Parse a \fIHH:MM\fR time string, noting that this avoids problems with
octal numbers by forcing interpretation as decimals (if we did not

   [\fBscan\fR $string " (%f ,%f %c" x y last] != 3
   || $last != 0x0029
} then {
   error "invalid coordinate string"
}
puts "X=$x, Y=$y"
.CE
.PP
.VS 8.5
An interactive session demonstrating the truncation of integer
values determined by size modifiers:
.CS
% set tcl_platform(wordSize)
4
% scan 20000000000000000000 %d
2147483647
% scan 20000000000000000000 %ld
9223372036854775807
% scan 20000000000000000000 %lld
20000000000000000000
.CE
.VE 8.5

.SH "SEE ALSO"
format(n), sscanf(3)

.SH KEYWORDS
conversion specifier, parse, scan

/*
 * tclScan.c --
 *
 *	This file contains the implementation of the "scan" command.
 *
 * Copyright (c) 1998 by Scriptics Corporation.
 *
 * See the file "license.terms" for information on usage and redistribution of
 * this file, and for a DISCLAIMER OF ALL WARRANTIES.
 *
 * RCS: @(#) $Id: tclScan.c,v 1.24 2006/04/25 17:15:25 dgp Exp $
 */

#include "tclInt.h"

/*
 * Flag values used by Tcl_ScanObjCmd.
 */

	    break;
	case 'x':
	    op = 'i';
	    parseFlag |= TCL_PARSE_HEXADECIMAL_ONLY;
	    break;
	case 'u':
	    op = 'i';
	    parseFlag |= TCL_PARSE_DECIMAL_ONLY;
	    flags |= SCAN_UNSIGNED;
	    break;

	case 'f':
	case 'e':
	case 'g':
	    op = 'f';

# Commands covered:  scan
#
# This file contains a collection of tests for one or more of the Tcl
# built-in commands.  Sourcing this file into Tcl runs the tests and
# generates output for errors.  No output means no errors were found.
#
# Copyright (c) 1991-1994 The Regents of the University of California.
# Copyright (c) 1994-1997 Sun Microsystems, Inc.
# Copyright (c) 1998-1999 by Scriptics Corporation.
#
# See the file "license.terms" for information on usage and redistribution
# of this file, and for a DISCLAIMER OF ALL WARRANTIES.
#
# RCS: @(#) $Id: scan.test,v 1.21 2006/04/25 17:15:25 dgp Exp $

if {[lsearch [namespace children] ::tcltest] == -1} {
    package require tcltest 2
    namespace import -force ::tcltest::*
}

testConstraint wideIs64bit \

    list [scan "7810179016327718216,6c63546f6c6c6548,661432506755433062510" \
	    %ld,%lx,%lo a b c] $a $b $c
} {3 7810179016327718216 7810179016327718216 7810179016327718216}
test scan-5.13 {integer scanning and overflow} {
    # This test used to fail on some 64-bit systems. [Bug 1011860]
    scan {300000000 3000000000 30000000000} {%ld %ld %ld}
} {300000000 3000000000 30000000000}

test scan-5.14 {integer scanning} {
    scan 0xff %u
} 0

test scan-6.1 {floating-point scanning} {
    set a {}; set b {}; set c {}; set d {}
    list [scan "2.1 -3.0e8 .99962 a" "%f%g%e%f" a b c d] $a $b $c $d
} {3 2.1 -300000000.0 0.99962 {}}
test scan-6.2 {floating-point scanning} {
    set a {}; set b {}; set c {}; set d {}