Tcl Source Code

/*
 * 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.
 */

#include "tclInt.h"

    notXpg:
	gotSequential = 1;
	if (gotXpg) {
	mixedXPG:
	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
		    "cannot mix \"%\" and \"%n$\" conversion specifiers",
		    -1));
	    Tcl_SetErrorCode(interp, "TCL", "FORMAT", "MIXEDSPECTYPES", NULL);
	    goto error;
	}

    xpgCheckDone:
	/*
	 * Parse any width specifier.
	 */

	switch (ch) {
	case 'c':
	    if (flags & SCAN_WIDTH) {
		Tcl_SetObjResult(interp, Tcl_NewStringObj(
			"field width may not be specified in %c conversion",
			-1));
		Tcl_SetErrorCode(interp, "TCL", "FORMAT", "BADWIDTH", NULL);
		goto error;
	    }
	    /* FALLTHRU */
	case 'n':
	case 's':
	    if (flags & (SCAN_LONGER|SCAN_BIG)) {
	    invalidFieldSize:
		buf[Tcl_UniCharToUtf(ch, buf)] = '\0';
		errorMsg = Tcl_NewStringObj(
			"field size modifier may not be specified in %", -1);
		Tcl_AppendToObj(errorMsg, buf, -1);
		Tcl_AppendToObj(errorMsg, " conversion", -1);
		Tcl_SetObjResult(interp, errorMsg);
		Tcl_SetErrorCode(interp, "TCL", "FORMAT", "BADSIZE", NULL);
		goto error;
	    }
	    /*
	     * Fall through!
	     */
	case 'd':
	case 'e':

		}
		format += TclUtfToUniChar(format, &ch);
	    }
	    break;
	badSet:
	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
		    "unmatched [ in format string", -1));
	    Tcl_SetErrorCode(interp, "TCL", "FORMAT", "BRACKET", NULL);
	    goto error;
	default:
	    buf[Tcl_UniCharToUtf(ch, buf)] = '\0';
	    errorMsg = Tcl_NewStringObj(
		    "bad scan conversion character \"", -1);
	    Tcl_AppendToObj(errorMsg, buf, -1);
	    Tcl_AppendToObj(errorMsg, "\"", -1);
	    Tcl_SetObjResult(interp, errorMsg);
	    Tcl_SetErrorCode(interp, "TCL", "FORMAT", "BADTYPE", NULL);
	    goto error;
	}
	if (!(flags & SCAN_SUPPRESS)) {
	    if (objIndex >= nspace) {
		/*
		 * Expand the nassign buffer. If we are using XPG specifiers,
		 * make sure that we grow to a large enough size. xpgSize is

	*totalSubs = numVars;
    }
    for (i = 0; i < numVars; i++) {
	if (nassign[i] > 1) {
	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
		    "variable is assigned by multiple \"%n$\" conversion specifiers",
		    -1));
	    Tcl_SetErrorCode(interp, "TCL", "FORMAT", "POLYASSIGNED", NULL);
	    goto error;
	} else if (!xpgSize && (nassign[i] == 0)) {
	    /*
	     * If the space is empty, and xpgSize is 0 (means XPG wasn't used,
	     * and/or numVars != 0), then too many vars were given
	     */

	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
		    "variable is not assigned by any conversion specifiers",
		    -1));
	    Tcl_SetErrorCode(interp, "TCL", "FORMAT", "UNASSIGNED", NULL);
	    goto error;
	}
    }

    TclStackFree(interp, nassign);
    return TCL_OK;

  badIndex:
    if (gotXpg) {
	Tcl_SetObjResult(interp, Tcl_NewStringObj(
		"\"%n$\" argument index out of range", -1));
	Tcl_SetErrorCode(interp, "TCL", "FORMAT", "INDEXRANGE", NULL);
    } else {
	Tcl_SetObjResult(interp, Tcl_NewStringObj(
		"different numbers of variable names and field specifiers",
		-1));
	Tcl_SetErrorCode(interp, "TCL", "FORMAT", "FIELDVARMISMATCH", NULL);
    }

  error:
    TclStackFree(interp, nassign);
    return TCL_ERROR;
}


	    break;

	case 'f':
	    /*
	     * Scan a floating point number
	     */

	    objPtr = Tcl_NewDoubleObj(0.0);
	    Tcl_IncrRefCount(objPtr);
	    if (width == 0) {
		width = ~0;
	    }
	    if (TCL_OK != TclParseNumber(NULL, objPtr, NULL, string, width,
		    &end, TCL_PARSE_DECIMAL_ONLY | TCL_PARSE_NO_WHITESPACE)) {
		Tcl_DecrRefCount(objPtr);

	TclNewObj(objPtr);
	for (i = 0; i < totalVars; i++) {
	    if (objs[i] != NULL) {
		Tcl_ListObjAppendElement(NULL, objPtr, objs[i]);
		Tcl_DecrRefCount(objs[i]);
	    } else {

		/*
		 * More %-specifiers than matching chars, so we just spit out
		 * empty strings for these.
		 */


		Tcl_ListObjAppendElement(NULL, objPtr, Tcl_NewObj());
	    }
	}
    }
    if (objs != NULL) {
	ckfree(objs);
    }
    if (code == TCL_OK) {

 * 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 "tommath.h"
#include "tclStringRep.h"

/*
 * Set COMPAT to 1 to restore the shimmering patterns to those of Tcl 8.5.
 * This is an escape hatch in case the changes have some unexpected unwelcome
 * impact on performance. If things go well, this mechanism can go away when
 * post-8.6 development begins.
 */

#define COMPAT 0

/*
 * Prototypes for functions defined later in this file:
 */

static void		AppendPrintfToObjVA(Tcl_Obj *objPtr,
			    const char *format, va_list argList);
static void		AppendUnicodeToUnicodeRep(Tcl_Obj *objPtr,

     * Preconditions:
     *	objPtr->typePtr == &tclStringType
     *	needed > stringPtr->maxChars
     *	needed < STRING_MAXCHARS
     */

    String *ptr = NULL, *stringPtr = GET_STRING(objPtr);
    int attempt;

    if (stringPtr->maxChars > 0) {
	/*
	 * Subsequent appends - apply the growth algorithm.
	 */

	if (needed <= STRING_MAXCHARS / 2) {
	    attempt = 2 * needed;
	    ptr = stringAttemptRealloc(stringPtr, attempt);
	}
	if (ptr == NULL) {
	    /*
	     * Take care computing the amount of modest growth to avoid
	     * overflow into invalid argument values for attempt.
	     */

	    unsigned int limit = STRING_MAXCHARS - needed;
	    unsigned int extra = needed - stringPtr->numChars
		    + TCL_MIN_UNICHAR_GROWTH;
	    int growth = (int) ((extra > limit) ? limit : extra);

	    attempt = needed + growth;
	    ptr = stringAttemptRealloc(stringPtr, attempt);
	}
    }
    if (ptr == NULL) {
	/*
	 * First allocation - just big enough; or last chance fallback.
	 */

	attempt = needed;
	ptr = stringRealloc(stringPtr, attempt);
    }
    stringPtr = ptr;
    stringPtr->maxChars = attempt;
    SET_STRING(objPtr, stringPtr);
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_NewStringObj --

    return Tcl_DbNewStringObj(bytes, length, "unknown", 0);
}
#else /* if not TCL_MEM_DEBUG */
Tcl_Obj *
Tcl_NewStringObj(
    const char *bytes,		/* Points to the first of the length bytes
				 * used to initialize the new object. */
    int length)			/* The number of bytes to copy from "bytes"
				 * when initializing the new object. If
				 * negative, use bytes up to the first NUL
				 * byte. */
{
    Tcl_Obj *objPtr;

    if (length < 0) {
	length = (bytes? strlen(bytes) : 0);
    }
    TclNewStringObj(objPtr, bytes, length);

 */

#ifdef TCL_MEM_DEBUG
Tcl_Obj *
Tcl_DbNewStringObj(
    const char *bytes,		/* Points to the first of the length bytes
				 * used to initialize the new object. */
    int length,			/* The number of bytes to copy from "bytes"
				 * when initializing the new object. If
				 * negative, use bytes up to the first NUL
				 * byte. */
    const char *file,		/* The name of the source file calling this
				 * function; used for debugging. */
    int line)			/* Line number in the source file; used for
				 * debugging. */
{
    Tcl_Obj *objPtr;

     * If numChars is unknown, compute it.
     */

    if (numChars == -1) {
	TclNumUtfChars(numChars, objPtr->bytes, objPtr->length);
	stringPtr->numChars = numChars;

#if COMPAT
	if (numChars < objPtr->length) {
	    /*
	     * Since we've just computed the number of chars, and not all UTF
	     * chars are 1-byte long, go ahead and populate the Unicode
	     * string.
	     */

	    FillUnicodeRep(objPtr);
	}
#endif
    }
    return numChars;
}

/*
 *----------------------------------------------------------------------
 *

Tcl_UniChar
Tcl_GetUniChar(
    Tcl_Obj *objPtr,		/* The object to get the Unicode charater
				 * from. */
    int index)			/* Get the index'th Unicode character. */
{
    String *stringPtr;
    int length;

    if (index < 0) {
	return 0xFFFD;
    }

    /*
     * Optimize the case where we're really dealing with a ByteArray object
     * we don't need to convert to a string to perform the indexing operation.
     */

    if (TclIsPureByteArray(objPtr)) {

	unsigned char *bytes = Tcl_GetByteArrayFromObj(objPtr, &length);
	if (index >= length) {
		return 0xFFFD;
	}

	return (Tcl_UniChar) bytes[index];
    }

    /*
     * OK, need to work with the object as a string.
     */

    SetStringFromAny(NULL, objPtr);

int
TclGetUCS4(
    Tcl_Obj *objPtr,		/* The object to get the Unicode character
				 * from. */
    int index)			/* Get the index'th Unicode character. */
{
    String *stringPtr;
    int ch, length;

    if (index < 0) {
	return -1;
    }

    /*
     * Optimize the case where we're really dealing with a ByteArray object
     * we don't need to convert to a string to perform the indexing operation.
     */

    if (TclIsPureByteArray(objPtr)) {

	unsigned char *bytes = Tcl_GetByteArrayFromObj(objPtr, &length);
	if (index >= length) {
		return -1;
	}

	return (int) bytes[index];
    }

    /*
     * OK, need to work with the object as a string.
     */

    SetStringFromAny(NULL, objPtr);

	if (stringPtr->numChars == -1) {
	    TclNumUtfChars(stringPtr->numChars, objPtr->bytes, objPtr->length);
	}
	if (index >= stringPtr->numChars) {
	    return -1;
	}
	if (stringPtr->numChars == objPtr->length) {
	    /* Pure ascii, can directly index bytes */
	    return (unsigned char) objPtr->bytes[index];
	}
	FillUnicodeRep(objPtr);
	stringPtr = GET_STRING(objPtr);
    }

    if (index >= stringPtr->numChars) {

/*
 *----------------------------------------------------------------------
 *
 * Tcl_GetRange --
 *
 *	Create a Tcl Object that contains the chars between first and last of
 *	the object indicated by "objPtr". If the object is not already a
 *	String object, convert it to one.  If first is negative, the returned
 *	string start at the beginning of objPtr.  If last is negative, the
 *	returned string ends at the end of objPtr.
 *
 * Results:
 *	Returns a new Tcl Object of the String type.
 *
 * Side effects:
 *	Changes the internal rep of "objPtr" to the String type.
 *

}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_SetObjLength --
 *
 *	This function changes the length of the string representation of an
 *	object.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	If the size of objPtr's string representation is greater than length,
 *	then it is reduced to length and a new terminating null byte is stored
 *	in the strength. If the length of the string representation is greater
 *	than length, the storage space is reallocated to the given length; a
 *	null byte is stored at the end, but other bytes past the end of the
 *	original string representation are undefined. The object's internal

 *	representation is changed to "expendable string".
 *
 *----------------------------------------------------------------------
 */

void
Tcl_SetObjLength(
    Tcl_Obj *objPtr,		/* Pointer to object. This object must not
				 * currently be shared. */
    int length)			/* Number of bytes desired for string
				 * representation of object, not including
				 * terminating null byte. */
{
    String *stringPtr;

    if (length < 0) {
	/*
	 * Setting to a negative length is nonsense. This is probably the
	 * result of overflowing the signed integer range.
	 */

	Tcl_Panic("Tcl_SetObjLength: negative length requested: "
		"%d (integer overflow?)", length);
    }
    if (Tcl_IsShared(objPtr)) {
	Tcl_Panic("%s called with shared object", "Tcl_SetObjLength");
    }

	    stringPtr->allocated = length;
	}

	objPtr->length = length;
	objPtr->bytes[length] = 0;

	/*
	 * Invalidate the unicode data.
	 */

	stringPtr->numChars = -1;
	stringPtr->hasUnicode = 0;
    } else {
	/*
	 * Changing length of pure unicode string.

    int length)			/* Number of bytes desired for string
				 * representation of object, not including
				 * terminating null byte. */
{
    String *stringPtr;

    if (length < 0) {
	/*
	 * Setting to a negative length is nonsense. This is probably the
	 * result of overflowing the signed integer range.
	 */

	return 0;
    }

    if (Tcl_IsShared(objPtr)) {
	Tcl_Panic("%s called with shared object", "Tcl_AttemptSetObjLength");
    }
    if (objPtr->bytes && objPtr->length == length) {
	return 1;
    }

static int
UnicodeLength(
    const Tcl_UniChar *unicode)
{
    int numChars = 0;

    if (unicode) {
	while (numChars >= 0 && unicode[numChars] != 0) {
	    numChars++;
	}
    }
    stringCheckLimits(numChars);
    return numChars;
}

    }

    if (length <= limit) {
	return;
    }

    stringPtr = GET_STRING(objPtr);
    if (stringPtr->hasUnicode && stringPtr->numChars > 0) {
	AppendUtfToUnicodeRep(objPtr, ellipsis, eLen);
    } else {
	AppendUtfToUtfRep(objPtr, ellipsis, eLen);
    }
}

/*

    /*
     * If objPtr has a valid Unicode rep, then append unicode to the
     * objPtr's Unicode rep, otherwise the UTF conversion of unicode to
     * objPtr's string rep.
     */

    if (stringPtr->hasUnicode
#if COMPAT
		&& stringPtr->numChars > 0
#endif
	    ) {
	AppendUnicodeToUnicodeRep(objPtr, unicode, length);
    } else {
	AppendUnicodeToUtfRep(objPtr, unicode, length);
    }
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_AppendObjToObj --
 *
 *	This function appends the string rep of one object to another.
 *	"objPtr" cannot be a shared object.

     * it did, then appending the byte arrays together could well lose
     * information; this is a special-case optimization only.
     */

    if ((TclIsPureByteArray(objPtr) || objPtr->bytes == tclEmptyStringRep)
	    && TclIsPureByteArray(appendObjPtr)) {
	/*
	 * You might expect the code here to be
	 *
	 *  bytes = Tcl_GetByteArrayFromObj(appendObjPtr, &length);
	 *  TclAppendBytesToByteArray(objPtr, bytes, length);
	 *
	 * and essentially all of the time that would be fine. However, it
	 * would run into trouble in the case where objPtr and appendObjPtr
	 * point to the same thing. That may never be a good idea. It seems to

    stringPtr = GET_STRING(objPtr);

    /*
     * If objPtr has a valid Unicode rep, then get a Unicode string from
     * appendObjPtr and append it.
     */

    if (stringPtr->hasUnicode
#if COMPAT
		&& stringPtr->numChars > 0
#endif
	    ) {
	/*
	 * If appendObjPtr is not of the "String" type, don't convert it.
	 */

	if (appendObjPtr->typePtr == &tclStringType) {
	    Tcl_UniChar *unicode =
		    Tcl_GetUnicodeFromObj(appendObjPtr, &numChars);

	String *appendStringPtr = GET_STRING(appendObjPtr);

	appendNumChars = appendStringPtr->numChars;
    }

    AppendUtfToUtfRep(objPtr, bytes, length);

    if (numChars >= 0 && appendNumChars >= 0
#if COMPAT
		&& appendNumChars == length
#endif
	    ) {
	stringPtr->numChars = numChars + appendNumChars;
    }
}

/*
 *----------------------------------------------------------------------
 *

    String *stringPtr = GET_STRING(objPtr);

    numChars = ExtendStringRepWithUnicode(objPtr, unicode, numChars);

    if (stringPtr->numChars != -1) {
	stringPtr->numChars += numChars;
    }

#if COMPAT
    /*
     * Invalidate the Unicode rep.
     */

    stringPtr->hasUnicode = 0;
#endif
}

/*
 *----------------------------------------------------------------------
 *
 * AppendUtfToUnicodeRep --
 *

    Tcl_Interp *interp,
    Tcl_Obj *appendObj,
    const char *format,
    int objc,
    Tcl_Obj *const objv[])
{
    const char *span = format, *msg, *errCode;
    int numBytes = 0, objIndex = 0, gotXpg = 0, gotSequential = 0;
    int originalLength, limit;
    Tcl_UniChar ch = 0;
    static const char *mixedXPG =
	    "cannot mix \"%\" and \"%n$\" conversion specifiers";
    static const char *const badIndex[2] = {
	"not enough arguments for all format specifiers",
	"\"%n$\" argument index out of range"
    };

    /*
     * Format string is NUL-terminated.
     */

    while (*format != '\0') {
	char *end;
	int gotMinus = 0, gotHash = 0, gotZero = 0, gotSpace = 0, gotPlus = 0;
	int width, gotPrecision, precision, sawFlag, useShort = 0, useBig = 0;

#ifndef TCL_WIDE_INT_IS_LONG
	int useWide = 0;
#endif

	int newXpg, numChars, allocSegment = 0, segmentLimit, segmentNumBytes;
	Tcl_Obj *segment;
	int step = TclUtfToUniChar(format, &ch);

	format += step;
	if (ch != '%') {
	    numBytes += step;
	    continue;

	    switch (ch) {
	    case 'd': {
		int length;
		Tcl_Obj *pure;
		const char *bytes;

		if (useShort) {
		    TclNewIntObj(pure, (int) s);
#ifndef TCL_WIDE_INT_IS_LONG
		} else if (useWide) {
		    pure = Tcl_NewWideIntObj(w);
#endif
		} else if (useBig) {
		    pure = Tcl_NewBignumObj(&big);
		} else {

	    }

	    case 'u':
	    case 'o':
	    case 'x':
	    case 'X':
	    case 'b': {
		Tcl_WideUInt bits = (Tcl_WideUInt) 0;
		Tcl_WideInt numDigits = (Tcl_WideInt) 0;
		int length, numBits = 4, base = 16, index = 0, shift = 0;

		Tcl_Obj *pure;
		char *bytes;

		if (ch == 'u') {
		    base = 10;
		} else if (ch == 'o') {
		    base = 8;

		 * Need to be sure zero becomes "0", not "".
		 */

		if ((numDigits == 0) && !((ch == 'o') && gotHash)) {
		    numDigits = 1;
		}
		TclNewObj(pure);
		Tcl_SetObjLength(pure, (int) numDigits);
		bytes = TclGetString(pure);
		toAppend = length = (int) numDigits;
		while (numDigits--) {
		    int digitOffset;

		    if (useBig && big.used) {
			if (index < big.used && (size_t) shift <
				CHAR_BIT*sizeof(Tcl_WideUInt) - MP_DIGIT_BIT) {
			    bits |= ((Tcl_WideUInt) big.dp[index++]) << shift;
			    shift += MP_DIGIT_BIT;
			}
			shift -= numBits;
		    }
		    digitOffset = (int) (bits % base);
		    if (digitOffset > 9) {
			if (ch == 'X') {
			    bytes[numDigits] = 'A' + digitOffset - 10;
			} else {
			    bytes[numDigits] = 'a' + digitOffset - 10;
			}
		    } else {

	    }
	    break;
	}
	default:
	    if (interp != NULL) {
		Tcl_SetObjResult(interp,
			Tcl_ObjPrintf("bad field specifier \"%c\"", ch));
		Tcl_SetErrorCode(interp, "TCL", "FORMAT", "BADTYPE", NULL);
	    }
	    goto error;
	}

	if (width>0 && numChars<0) {
	    numChars = Tcl_GetCharLength(segment);
	}

    }

    return TCL_OK;

  errorMsg:
    if (interp != NULL) {
	Tcl_SetObjResult(interp, Tcl_NewStringObj(msg, -1));
	Tcl_SetErrorCode(interp, "TCL", "FORMAT", errCode, NULL);
    }
  error:
    Tcl_SetObjLength(appendObj, originalLength);
    return TCL_ERROR;
}

/*

static void
AppendPrintfToObjVA(
    Tcl_Obj *objPtr,
    const char *format,
    va_list argList)
{
    int code, objc;

    Tcl_Obj **objv, *list;
    const char *p;

    TclNewObj(list);
    p = format;
    Tcl_IncrRefCount(list);
    while (*p != '\0') {

		/*
		 * Within that buffer, we trim both ends if needed so that we
		 * copy only whole characters, and avoid copying any partial
		 * multi-byte characters.
		 */

		q = TclUtfPrev(end, bytes);
		if (!Tcl_UtfCharComplete(q, (int)(end - q))) {
		    end = q;
		}

		q = bytes + TCL_UTF_MAX;
		while ((bytes < end) && (bytes < q)
			&& ((*bytes & 0xC0) == 0x80)) {
		    bytes++;
		}

		Tcl_ListObjAppendElement(NULL, list,
			Tcl_NewStringObj(bytes , (int)(end - bytes)));

		break;
	    }
	    case 'c':
	    case 'i':
	    case 'u':
	    case 'd':
	    case 'o':
	    case 'x':
	    case 'X':
		seekingConversion = 0;
		switch (size) {
		case -1:
		case 0:
		    Tcl_ListObjAppendElement(NULL, list, Tcl_NewLongObj(
			    (long)va_arg(argList, int)));
		    break;
		case 1:
		    Tcl_ListObjAppendElement(NULL, list, NewLongObj(*p,
			    va_arg(argList, long)));
		    break;
		}
		break;
	    case 'e':
	    case 'E':
	    case 'f':
	    case 'g':
	    case 'G':
		Tcl_ListObjAppendElement(NULL, list, Tcl_NewDoubleObj(
			va_arg(argList, double)));
		seekingConversion = 0;
		break;
	    case '*':
		lastNum = (int) va_arg(argList, int);
		Tcl_ListObjAppendElement(NULL, list, Tcl_NewIntObj(lastNum));
		p++;
		break;
	    case '0': case '1': case '2': case '3': case '4':
	    case '5': case '6': case '7': case '8': case '9': {
		char *end;

		lastNum = (int) strtoul(p, &end, 10);
		p = end;
		break;
	    }
	    case '.':
		gotPrecision = 1;
		p++;
		break;

				 * an internal rep of type "String". */
    Tcl_Obj *copyPtr)		/* Object with internal rep to set. Must not
				 * currently have an internal rep.*/
{
    String *srcStringPtr = GET_STRING(srcPtr);
    String *copyStringPtr = NULL;

#if COMPAT==0
    if (srcStringPtr->numChars == -1) {
	/*
	 * The String struct in the source value holds zero useful data. Don't
	 * bother copying it. Don't even bother allocating space in which to
	 * copy it. Just let the copy be untyped.
	 */

	return;
    }

    if (srcStringPtr->hasUnicode) {
	int copyMaxChars;

	if (srcStringPtr->maxChars / 2 >= srcStringPtr->numChars) {

    /*
     * Tricky point: the string value was copied by generic object management
     * code, so it doesn't contain any extra bytes that might exist in the
     * source object.
     */

    copyStringPtr->allocated = copyPtr->bytes ? copyPtr->length : 0;
#else /* COMPAT!=0 */
    /*
     * If the src obj is a string of 1-byte Utf chars, then copy the string
     * rep of the source object and create an "empty" Unicode internal rep for
     * the new object. Otherwise, copy Unicode internal rep, and invalidate
     * the string rep of the new object.
     */

    if (srcStringPtr->hasUnicode && srcStringPtr->numChars > 0) {
	/*
	 * Copy the full allocation for the Unicode buffer.
	 */

	copyStringPtr = stringAlloc(srcStringPtr->maxChars);
	copyStringPtr->maxChars = srcStringPtr->maxChars;
	memcpy(copyStringPtr->unicode, srcStringPtr->unicode,
		srcStringPtr->numChars * sizeof(Tcl_UniChar));
	copyStringPtr->unicode[srcStringPtr->numChars] = 0;
	copyStringPtr->allocated = 0;
    } else {
	copyStringPtr = stringAlloc(0);
	copyStringPtr->unicode[0] = 0;
	copyStringPtr->maxChars = 0;

	/*
	 * Tricky point: the string value was copied by generic object
	 * management code, so it doesn't contain any extra bytes that might
	 * exist in the source object.
	 */

	copyStringPtr->allocated = copyPtr->length;
    }
    copyStringPtr->numChars = srcStringPtr->numChars;
    copyStringPtr->hasUnicode = srcStringPtr->hasUnicode;
#endif /* COMPAT==0 */

    SET_STRING(copyPtr, copyStringPtr);
    copyPtr->typePtr = &tclStringType;
}

/*
 *----------------------------------------------------------------------
 *
 * SetStringFromAny --
 *
 *	Create an internal representation of type "String" for an object.
 *
 * Results:
 *	This operation always succeeds and returns TCL_OK.
 *
 * Side effects:
 *	Any old internal representation for objPtr is freed and the internal
 *	representation is set to "String".
 *
 *----------------------------------------------------------------------
 */

static int
SetStringFromAny(
    Tcl_Interp *interp,		/* Used for error reporting if not NULL. */