Initial revision

1 files changed, 2807 insertions, 0 deletions

diff --git a/generic/tclUtil.c b/generic/tclUtil.c
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--- /dev/null
+++ b/generic/tclUtil.c
@@ -0,0 +1,2807 @@
+/* 
+ * tclUtil.c --
+ *
+ *	This file contains utility procedures that are used by many Tcl
+ *	commands.
+ *
+ * Copyright (c) 1987-1993 The Regents of the University of California.
+ * Copyright (c) 1994-1997 Sun Microsystems, Inc.
+ *
+ * See the file "license.terms" for information on usage and redistribution
+ * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
+ *
+ * SCCS: @(#) tclUtil.c 1.161 97/08/12 17:07:18
+ */
+
+#include "tclInt.h"
+#include "tclPort.h"
+
+/*
+ * The following values are used in the flags returned by Tcl_ScanElement
+ * and used by Tcl_ConvertElement.  The value TCL_DONT_USE_BRACES is also
+ * defined in tcl.h;  make sure its value doesn't overlap with any of the
+ * values below.
+ *
+ * TCL_DONT_USE_BRACES -	1 means the string mustn't be enclosed in
+ *				braces (e.g. it contains unmatched braces,
+ *				or ends in a backslash character, or user
+ *				just doesn't want braces);  handle all
+ *				special characters by adding backslashes.
+ * USE_BRACES -			1 means the string contains a special
+ *				character that can be handled simply by
+ *				enclosing the entire argument in braces.
+ * BRACES_UNMATCHED -		1 means that braces aren't properly matched
+ *				in the argument.
+ */
+
+#define USE_BRACES		2
+#define BRACES_UNMATCHED	4
+
+/*
+ * The following values determine the precision used when converting
+ * floating-point values to strings.  This information is linked to all
+ * of the tcl_precision variables in all interpreters via the procedure
+ * TclPrecTraceProc.
+ *
+ * NOTE: these variables are not thread-safe.
+ */
+
+static char precisionString[10] = "12";
+				/* The string value of all the tcl_precision
+				 * variables. */
+static char precisionFormat[10] = "%.12g";
+				/* The format string actually used in calls
+				 * to sprintf. */
+
+
+/*
+ * Function prototypes for local procedures in this file:
+ */
+
+static void		SetupAppendBuffer _ANSI_ARGS_((Interp *iPtr,
+			    int newSpace));
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclFindElement --
+ *
+ *	Given a pointer into a Tcl list, locate the first (or next)
+ *	element in the list.
+ *
+ * Results:
+ *	The return value is normally TCL_OK, which means that the
+ *	element was successfully located.  If TCL_ERROR is returned
+ *	it means that list didn't have proper list structure;
+ *	interp->result contains a more detailed error message.
+ *
+ *	If TCL_OK is returned, then *elementPtr will be set to point to the
+ *	first element of list, and *nextPtr will be set to point to the
+ *	character just after any white space following the last character
+ *	that's part of the element. If this is the last argument in the
+ *	list, then *nextPtr will point just after the last character in the
+ *	list (i.e., at the character at list+listLength). If sizePtr is
+ *	non-NULL, *sizePtr is filled in with the number of characters in the
+ *	element.  If the element is in braces, then *elementPtr will point
+ *	to the character after the opening brace and *sizePtr will not
+ *	include either of the braces. If there isn't an element in the list,
+ *	*sizePtr will be zero, and both *elementPtr and *termPtr will point
+ *	just after the last character in the list. Note: this procedure does
+ *	NOT collapse backslash sequences.
+ *
+ * Side effects:
+ *	None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+TclFindElement(interp, list, listLength, elementPtr, nextPtr, sizePtr,
+	       bracePtr)
+    Tcl_Interp *interp;		/* Interpreter to use for error reporting. 
+				 * If NULL, then no error message is left
+				 * after errors. */
+    char *list;			/* Points to the first byte of a string
+				 * containing a Tcl list with zero or more
+				 * elements (possibly in braces). */
+    int listLength;		/* Number of bytes in the list's string. */
+    char **elementPtr;		/* Where to put address of first significant
+				 * character in first element of list. */
+    char **nextPtr;		/* Fill in with location of character just
+				 * after all white space following end of
+				 * argument (next arg or end of list). */
+    int *sizePtr;		/* If non-zero, fill in with size of
+				 * element. */
+    int *bracePtr;		/* If non-zero, fill in with non-zero/zero
+				 * to indicate that arg was/wasn't
+				 * in braces. */
+{
+    char *p = list;
+    char *elemStart;		/* Points to first byte of first element. */
+    char *limit;		/* Points just after list's last byte. */
+    int openBraces = 0;		/* Brace nesting level during parse. */
+    int inQuotes = 0;
+    int size = 0;		/* Init. avoids compiler warning. */
+    int numChars;
+    char *p2;
+    
+    /*
+     * Skim off leading white space and check for an opening brace or
+     * quote. We treat embedded NULLs in the list as bytes belonging to
+     * a list element. Note: use of "isascii" below and elsewhere in this
+     * procedure is a temporary hack (7/27/90) because Mx uses characters
+     * with the high-order bit set for some things. This should probably
+     * be changed back eventually, or all of Tcl should call isascii.
+     */
+
+    limit = (list + listLength);
+    while ((p < limit) && (isspace(UCHAR(*p)))) {
+	p++;
+    }
+    if (p == limit) {		/* no element found */
+	elemStart = limit;
+	goto done;
+    }
+
+    if (*p == '{') {
+	openBraces = 1;
+	p++;
+    } else if (*p == '"') {
+	inQuotes = 1;
+	p++;
+    }
+    elemStart = p;
+    if (bracePtr != 0) {
+	*bracePtr = openBraces;
+    }
+
+    /*
+     * Find element's end (a space, close brace, or the end of the string).
+     */
+
+    while (p < limit) {
+	switch (*p) {
+
+	    /*
+	     * Open brace: don't treat specially unless the element is in
+	     * braces. In this case, keep a nesting count.
+	     */
+
+	    case '{':
+		if (openBraces != 0) {
+		    openBraces++;
+		}
+		break;
+
+	    /*
+	     * Close brace: if element is in braces, keep nesting count and
+	     * quit when the last close brace is seen.
+	     */
+
+	    case '}':
+		if (openBraces > 1) {
+		    openBraces--;
+		} else if (openBraces == 1) {
+		    size = (p - elemStart);
+		    p++;
+		    if ((p >= limit) || isspace(UCHAR(*p))) {
+			goto done;
+		    }
+
+		    /*
+		     * Garbage after the closing brace; return an error.
+		     */
+		    
+		    if (interp != NULL) {
+			char buf[100];
+			
+			p2 = p;
+			while ((p2 < limit) && (!isspace(UCHAR(*p2)))
+			        && (p2 < p+20)) {
+			    p2++;
+			}
+			sprintf(buf,
+				"list element in braces followed by \"%.*s\" instead of space",
+				(int) (p2-p), p);
+			Tcl_SetResult(interp, buf, TCL_VOLATILE);
+		    }
+		    return TCL_ERROR;
+		}
+		break;
+
+	    /*
+	     * Backslash:  skip over everything up to the end of the
+	     * backslash sequence.
+	     */
+
+	    case '\\': {
+		(void) Tcl_Backslash(p, &numChars);
+		p += (numChars - 1);
+		break;
+	    }
+
+	    /*
+	     * Space: ignore if element is in braces or quotes; otherwise
+	     * terminate element.
+	     */
+
+	    case ' ':
+	    case '\f':
+	    case '\n':
+	    case '\r':
+	    case '\t':
+	    case '\v':
+		if ((openBraces == 0) && !inQuotes) {
+		    size = (p - elemStart);
+		    goto done;
+		}
+		break;
+
+	    /*
+	     * Double-quote: if element is in quotes then terminate it.
+	     */
+
+	    case '"':
+		if (inQuotes) {
+		    size = (p - elemStart);
+		    p++;
+		    if ((p >= limit) || isspace(UCHAR(*p))) {
+			goto done;
+		    }
+
+		    /*
+		     * Garbage after the closing quote; return an error.
+		     */
+		    
+		    if (interp != NULL) {
+			char buf[100];
+			
+			p2 = p;
+			while ((p2 < limit) && (!isspace(UCHAR(*p2)))
+				 && (p2 < p+20)) {
+			    p2++;
+			}
+			sprintf(buf,
+				"list element in quotes followed by \"%.*s\" %s",
+				(int) (p2-p), p, "instead of space");
+			Tcl_SetResult(interp, buf, TCL_VOLATILE);
+		    }
+		    return TCL_ERROR;
+		}
+		break;
+	}
+	p++;
+    }
+
+
+    /*
+     * End of list: terminate element.
+     */
+
+    if (p == limit) {
+	if (openBraces != 0) {
+	    if (interp != NULL) {
+		Tcl_SetResult(interp, "unmatched open brace in list",
+			TCL_STATIC);
+	    }
+	    return TCL_ERROR;
+	} else if (inQuotes) {
+	    if (interp != NULL) {
+		Tcl_SetResult(interp, "unmatched open quote in list",
+			TCL_STATIC);
+	    }
+	    return TCL_ERROR;
+	}
+	size = (p - elemStart);
+    }
+
+    done:
+    while ((p < limit) && (isspace(UCHAR(*p)))) {
+	p++;
+    }
+    *elementPtr = elemStart;
+    *nextPtr = p;
+    if (sizePtr != 0) {
+	*sizePtr = size;
+    }
+    return TCL_OK;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclCopyAndCollapse --
+ *
+ *	Copy a string and eliminate any backslashes that aren't in braces.
+ *
+ * Results:
+ *	There is no return value. Count characters get copied from src to
+ *	dst. Along the way, if backslash sequences are found outside braces,
+ *	the backslashes are eliminated in the copy. After scanning count
+ *	chars from source, a null character is placed at the end of dst.
+ *	Returns the number of characters that got copied.
+ *
+ * Side effects:
+ *	None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+TclCopyAndCollapse(count, src, dst)
+    int count;			/* Number of characters to copy from src. */
+    char *src;			/* Copy from here... */
+    char *dst;			/* ... to here. */
+{
+    char c;
+    int numRead;
+    int newCount = 0;
+
+    for (c = *src;  count > 0;  src++, c = *src, count--) {
+	if (c == '\\') {
+	    *dst = Tcl_Backslash(src, &numRead);
+	    dst++;
+	    src += numRead-1;
+	    count -= numRead-1;
+	    newCount++;
+	} else {
+	    *dst = c;
+	    dst++;
+	    newCount++;
+	}
+    }
+    *dst = 0;
+    return newCount;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_SplitList --
+ *
+ *	Splits a list up into its constituent fields.
+ *
+ * Results
+ *	The return value is normally TCL_OK, which means that
+ *	the list was successfully split up.  If TCL_ERROR is
+ *	returned, it means that "list" didn't have proper list
+ *	structure;  interp->result will contain a more detailed
+ *	error message.
+ *
+ *	*argvPtr will be filled in with the address of an array
+ *	whose elements point to the elements of list, in order.
+ *	*argcPtr will get filled in with the number of valid elements
+ *	in the array.  A single block of memory is dynamically allocated
+ *	to hold both the argv array and a copy of the list (with
+ *	backslashes and braces removed in the standard way).
+ *	The caller must eventually free this memory by calling free()
+ *	on *argvPtr.  Note:  *argvPtr and *argcPtr are only modified
+ *	if the procedure returns normally.
+ *
+ * Side effects:
+ *	Memory is allocated.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+Tcl_SplitList(interp, list, argcPtr, argvPtr)
+    Tcl_Interp *interp;		/* Interpreter to use for error reporting. 
+				 * If NULL, no error message is left. */
+    char *list;			/* Pointer to string with list structure. */
+    int *argcPtr;		/* Pointer to location to fill in with
+				 * the number of elements in the list. */
+    char ***argvPtr;		/* Pointer to place to store pointer to
+				 * array of pointers to list elements. */
+{
+    char **argv;
+    char *p;
+    int length, size, i, result, elSize, brace;
+    char *element;
+
+    /*
+     * Figure out how much space to allocate.  There must be enough
+     * space for both the array of pointers and also for a copy of
+     * the list.  To estimate the number of pointers needed, count
+     * the number of space characters in the list.
+     */
+
+    for (size = 1, p = list; *p != 0; p++) {
+	if (isspace(UCHAR(*p))) {
+	    size++;
+	}
+    }
+    size++;			/* Leave space for final NULL pointer. */
+    argv = (char **) ckalloc((unsigned)
+	    ((size * sizeof(char *)) + (p - list) + 1));
+    length = strlen(list);
+    for (i = 0, p = ((char *) argv) + size*sizeof(char *);
+	    *list != 0;  i++) {
+	char *prevList = list;
+	
+	result = TclFindElement(interp, list, length, &element,
+				&list, &elSize, &brace);
+	length -= (list - prevList);
+	if (result != TCL_OK) {
+	    ckfree((char *) argv);
+	    return result;
+	}
+	if (*element == 0) {
+	    break;
+	}
+	if (i >= size) {
+	    ckfree((char *) argv);
+	    if (interp != NULL) {
+		Tcl_SetResult(interp, "internal error in Tcl_SplitList",
+			TCL_STATIC);
+	    }
+	    return TCL_ERROR;
+	}
+	argv[i] = p;
+	if (brace) {
+	    memcpy((VOID *) p, (VOID *) element, (size_t) elSize);
+	    p += elSize;
+	    *p = 0;
+	    p++;
+	} else {
+	    TclCopyAndCollapse(elSize, element, p);
+	    p += elSize+1;
+	}
+    }
+
+    argv[i] = NULL;
+    *argvPtr = argv;
+    *argcPtr = i;
+    return TCL_OK;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_ScanElement --
+ *
+ *	This procedure is a companion procedure to Tcl_ConvertElement.
+ *	It scans a string to see what needs to be done to it (e.g. add
+ *	backslashes or enclosing braces) to make the string into a
+ *	valid Tcl list element.
+ *
+ * Results:
+ *	The return value is an overestimate of the number of characters
+ *	that will be needed by Tcl_ConvertElement to produce a valid
+ *	list element from string.  The word at *flagPtr is filled in
+ *	with a value needed by Tcl_ConvertElement when doing the actual
+ *	conversion.
+ *
+ * Side effects:
+ *	None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+Tcl_ScanElement(string, flagPtr)
+    CONST char *string;		/* String to convert to Tcl list element. */
+    int *flagPtr;		/* Where to store information to guide
+				 * Tcl_ConvertCountedElement. */
+{
+    return Tcl_ScanCountedElement(string, -1, flagPtr);
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_ScanCountedElement --
+ *
+ *	This procedure is a companion procedure to
+ *	Tcl_ConvertCountedElement.  It scans a string to see what
+ *	needs to be done to it (e.g. add backslashes or enclosing
+ *	braces) to make the string into a valid Tcl list element.
+ *	If length is -1, then the string is scanned up to the first
+ *	null byte.
+ *
+ * Results:
+ *	The return value is an overestimate of the number of characters
+ *	that will be needed by Tcl_ConvertCountedElement to produce a
+ *	valid list element from string.  The word at *flagPtr is
+ *	filled in with a value needed by Tcl_ConvertCountedElement
+ *	when doing the actual conversion.
+ *
+ * Side effects:
+ *	None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+Tcl_ScanCountedElement(string, length, flagPtr)
+    CONST char *string;		/* String to convert to Tcl list element. */
+    int length;			/* Number of bytes in string, or -1. */
+    int *flagPtr;		/* Where to store information to guide
+				 * Tcl_ConvertElement. */
+{
+    int flags, nestingLevel;
+    CONST char *p, *lastChar;
+
+    /*
+     * This procedure and Tcl_ConvertElement together do two things:
+     *
+     * 1. They produce a proper list, one that will yield back the
+     * argument strings when evaluated or when disassembled with
+     * Tcl_SplitList.  This is the most important thing.
+     * 
+     * 2. They try to produce legible output, which means minimizing the
+     * use of backslashes (using braces instead).  However, there are
+     * some situations where backslashes must be used (e.g. an element
+     * like "{abc": the leading brace will have to be backslashed.
+     * For each element, one of three things must be done:
+     *
+     * (a) Use the element as-is (it doesn't contain any special
+     * characters).  This is the most desirable option.
+     *
+     * (b) Enclose the element in braces, but leave the contents alone.
+     * This happens if the element contains embedded space, or if it
+     * contains characters with special interpretation ($, [, ;, or \),
+     * or if it starts with a brace or double-quote, or if there are
+     * no characters in the element.
+     *
+     * (c) Don't enclose the element in braces, but add backslashes to
+     * prevent special interpretation of special characters.  This is a
+     * last resort used when the argument would normally fall under case
+     * (b) but contains unmatched braces.  It also occurs if the last
+     * character of the argument is a backslash or if the element contains
+     * a backslash followed by newline.
+     *
+     * The procedure figures out how many bytes will be needed to store
+     * the result (actually, it overestimates). It also collects information
+     * about the element in the form of a flags word.
+     *
+     * Note: list elements produced by this procedure and
+     * Tcl_ConvertCountedElement must have the property that they can be
+     * enclosing in curly braces to make sub-lists.  This means, for
+     * example, that we must not leave unmatched curly braces in the
+     * resulting list element.  This property is necessary in order for
+     * procedures like Tcl_DStringStartSublist to work.
+     */
+
+    nestingLevel = 0;
+    flags = 0;
+    if (string == NULL) {
+	string = "";
+    }
+    if (length == -1) {
+	length = strlen(string);
+    }
+    lastChar = string + length;
+    p = string;
+    if ((p == lastChar) || (*p == '{') || (*p == '"')) {
+	flags |= USE_BRACES;
+    }
+    for ( ; p != lastChar; p++) {
+	switch (*p) {
+	    case '{':
+		nestingLevel++;
+		break;
+	    case '}':
+		nestingLevel--;
+		if (nestingLevel < 0) {
+		    flags |= TCL_DONT_USE_BRACES|BRACES_UNMATCHED;
+		}
+		break;
+	    case '[':
+	    case '$':
+	    case ';':
+	    case ' ':
+	    case '\f':
+	    case '\n':
+	    case '\r':
+	    case '\t':
+	    case '\v':
+		flags |= USE_BRACES;
+		break;
+	    case '\\':
+		if ((p+1 == lastChar) || (p[1] == '\n')) {
+		    flags = TCL_DONT_USE_BRACES | BRACES_UNMATCHED;
+		} else {
+		    int size;
+
+		    (void) Tcl_Backslash(p, &size);
+		    p += size-1;
+		    flags |= USE_BRACES;
+		}
+		break;
+	}
+    }
+    if (nestingLevel != 0) {
+	flags = TCL_DONT_USE_BRACES | BRACES_UNMATCHED;
+    }
+    *flagPtr = flags;
+
+    /*
+     * Allow enough space to backslash every character plus leave
+     * two spaces for braces.
+     */
+
+    return 2*(p-string) + 2;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_ConvertElement --
+ *
+ *	This is a companion procedure to Tcl_ScanElement.  Given
+ *	the information produced by Tcl_ScanElement, this procedure
+ *	converts a string to a list element equal to that string.
+ *
+ * Results:
+ *	Information is copied to *dst in the form of a list element
+ *	identical to src (i.e. if Tcl_SplitList is applied to dst it
+ *	will produce a string identical to src).  The return value is
+ *	a count of the number of characters copied (not including the
+ *	terminating NULL character).
+ *
+ * Side effects:
+ *	None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+Tcl_ConvertElement(src, dst, flags)
+    CONST char *src;		/* Source information for list element. */
+    char *dst;			/* Place to put list-ified element. */
+    int flags;			/* Flags produced by Tcl_ScanElement. */
+{
+    return Tcl_ConvertCountedElement(src, -1, dst, flags);
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_ConvertCountedElement --
+ *
+ *	This is a companion procedure to Tcl_ScanCountedElement.  Given
+ *	the information produced by Tcl_ScanCountedElement, this
+ *	procedure converts a string to a list element equal to that
+ *	string.
+ *
+ * Results:
+ *	Information is copied to *dst in the form of a list element
+ *	identical to src (i.e. if Tcl_SplitList is applied to dst it
+ *	will produce a string identical to src).  The return value is
+ *	a count of the number of characters copied (not including the
+ *	terminating NULL character).
+ *
+ * Side effects:
+ *	None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+Tcl_ConvertCountedElement(src, length, dst, flags)
+    CONST char *src;		/* Source information for list element. */
+    int length;			/* Number of bytes in src, or -1. */
+    char *dst;			/* Place to put list-ified element. */
+    int flags;			/* Flags produced by Tcl_ScanElement. */
+{
+    char *p = dst;
+    CONST char *lastChar;
+
+    /*
+     * See the comment block at the beginning of the Tcl_ScanElement
+     * code for details of how this works.
+     */
+
+    if (src && length == -1) {
+	length = strlen(src);
+    }
+    if ((src == NULL) || (length == 0)) {
+	p[0] = '{';
+	p[1] = '}';
+	p[2] = 0;
+	return 2;
+    }
+    lastChar = src + length;
+    if ((flags & USE_BRACES) && !(flags & TCL_DONT_USE_BRACES)) {
+	*p = '{';
+	p++;
+	for ( ; src != lastChar; src++, p++) {
+	    *p = *src;
+	}
+	*p = '}';
+	p++;
+    } else {
+	if (*src == '{') {
+	    /*
+	     * Can't have a leading brace unless the whole element is
+	     * enclosed in braces.  Add a backslash before the brace.
+	     * Furthermore, this may destroy the balance between open
+	     * and close braces, so set BRACES_UNMATCHED.
+	     */
+
+	    p[0] = '\\';
+	    p[1] = '{';
+	    p += 2;
+	    src++;
+	    flags |= BRACES_UNMATCHED;
+	}
+	for (; src != lastChar; src++) {
+	    switch (*src) {
+		case ']':
+		case '[':
+		case '$':
+		case ';':
+		case ' ':
+		case '\\':
+		case '"':
+		    *p = '\\';
+		    p++;
+		    break;
+		case '{':
+		case '}':
+		    /*
+		     * It may not seem necessary to backslash braces, but
+		     * it is.  The reason for this is that the resulting
+		     * list element may actually be an element of a sub-list
+		     * enclosed in braces (e.g. if Tcl_DStringStartSublist
+		     * has been invoked), so there may be a brace mismatch
+		     * if the braces aren't backslashed.
+		     */
+
+		    if (flags & BRACES_UNMATCHED) {
+			*p = '\\';
+			p++;
+		    }
+		    break;
+		case '\f':
+		    *p = '\\';
+		    p++;
+		    *p = 'f';
+		    p++;
+		    continue;
+		case '\n':
+		    *p = '\\';
+		    p++;
+		    *p = 'n';
+		    p++;
+		    continue;
+		case '\r':
+		    *p = '\\';
+		    p++;
+		    *p = 'r';
+		    p++;
+		    continue;
+		case '\t':
+		    *p = '\\';
+		    p++;
+		    *p = 't';
+		    p++;
+		    continue;
+		case '\v':
+		    *p = '\\';
+		    p++;
+		    *p = 'v';
+		    p++;
+		    continue;
+	    }
+	    *p = *src;
+	    p++;
+	}
+    }
+    *p = '\0';
+    return p-dst;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_Merge --
+ *
+ *	Given a collection of strings, merge them together into a
+ *	single string that has proper Tcl list structured (i.e.
+ *	Tcl_SplitList may be used to retrieve strings equal to the
+ *	original elements, and Tcl_Eval will parse the string back
+ *	into its original elements).
+ *
+ * Results:
+ *	The return value is the address of a dynamically-allocated
+ *	string containing the merged list.
+ *
+ * Side effects:
+ *	None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+char *
+Tcl_Merge(argc, argv)
+    int argc;			/* How many strings to merge. */
+    char **argv;		/* Array of string values. */
+{
+#   define LOCAL_SIZE 20
+    int localFlags[LOCAL_SIZE], *flagPtr;
+    int numChars;
+    char *result;
+    char *dst;
+    int i;
+
+    /*
+     * Pass 1: estimate space, gather flags.
+     */
+
+    if (argc <= LOCAL_SIZE) {
+	flagPtr = localFlags;
+    } else {
+	flagPtr = (int *) ckalloc((unsigned) argc*sizeof(int));
+    }
+    numChars = 1;
+    for (i = 0; i < argc; i++) {
+	numChars += Tcl_ScanElement(argv[i], &flagPtr[i]) + 1;
+    }
+
+    /*
+     * Pass two: copy into the result area.
+     */
+
+    result = (char *) ckalloc((unsigned) numChars);
+    dst = result;
+    for (i = 0; i < argc; i++) {
+	numChars = Tcl_ConvertElement(argv[i], dst, flagPtr[i]);
+	dst += numChars;
+	*dst = ' ';
+	dst++;
+    }
+    if (dst == result) {
+	*dst = 0;
+    } else {
+	dst[-1] = 0;
+    }
+
+    if (flagPtr != localFlags) {
+	ckfree((char *) flagPtr);
+    }
+    return result;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_Concat --
+ *
+ *	Concatenate a set of strings into a single large string.
+ *
+ * Results:
+ *	The return value is dynamically-allocated string containing
+ *	a concatenation of all the strings in argv, with spaces between
+ *	the original argv elements.
+ *
+ * Side effects:
+ *	Memory is allocated for the result;  the caller is responsible
+ *	for freeing the memory.
+ *
+ *----------------------------------------------------------------------
+ */
+
+char *
+Tcl_Concat(argc, argv)
+    int argc;			/* Number of strings to concatenate. */
+    char **argv;		/* Array of strings to concatenate. */
+{
+    int totalSize, i;
+    char *p;
+    char *result;
+
+    for (totalSize = 1, i = 0; i < argc; i++) {
+	totalSize += strlen(argv[i]) + 1;
+    }
+    result = (char *) ckalloc((unsigned) totalSize);
+    if (argc == 0) {
+	*result = '\0';
+	return result;
+    }
+    for (p = result, i = 0; i < argc; i++) {
+	char *element;
+	int length;
+
+	/*
+	 * Clip white space off the front and back of the string
+	 * to generate a neater result, and ignore any empty
+	 * elements.
+	 */
+
+	element = argv[i];
+	while (isspace(UCHAR(*element))) {
+	    element++;
+	}
+	for (length = strlen(element);
+		(length > 0) && (isspace(UCHAR(element[length-1])))
+		&& ((length < 2) || (element[length-2] != '\\'));
+		length--) {
+	    /* Null loop body. */
+	}
+	if (length == 0) {
+	    continue;
+	}
+	memcpy((VOID *) p, (VOID *) element, (size_t) length);
+	p += length;
+	*p = ' ';
+	p++;
+    }
+    if (p != result) {
+	p[-1] = 0;
+    } else {
+	*p = 0;
+    }
+    return result;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_ConcatObj --
+ *
+ *	Concatenate the strings from a set of objects into a single string
+ *	object with spaces between the original strings.
+ *
+ * Results:
+ *	The return value is a new string object containing a concatenation
+ *	of the strings in objv. Its ref count is zero.
+ *
+ * Side effects:
+ *	A new object is created.
+ *
+ *----------------------------------------------------------------------
+ */
+
+Tcl_Obj *
+Tcl_ConcatObj(objc, objv)
+    int objc;			/* Number of objects to concatenate. */
+    Tcl_Obj *CONST objv[];	/* Array of objects to concatenate. */
+{
+    int allocSize, finalSize, length, elemLength, i;
+    char *p;
+    char *element;
+    char *concatStr;
+    Tcl_Obj *objPtr;
+
+    allocSize = 0;
+    for (i = 0;  i < objc;  i++) {
+	objPtr = objv[i];
+	element = TclGetStringFromObj(objPtr, &length);
+	if ((element != NULL) && (length > 0)) {
+	    allocSize += (length + 1);
+	}
+    }
+    if (allocSize == 0) {
+	allocSize = 1;		/* enough for the NULL byte at end */
+    }
+
+    /*
+     * Allocate storage for the concatenated result. Note that allocSize
+     * is one more than the total number of characters, and so includes
+     * room for the terminating NULL byte.
+     */
+    
+    concatStr = (char *) ckalloc((unsigned) allocSize);
+
+    /*
+     * Now concatenate the elements. Clip white space off the front and back
+     * to generate a neater result, and ignore any empty elements. Also put
+     * a null byte at the end.
+     */
+
+    finalSize = 0;
+    if (objc == 0) {
+	*concatStr = '\0';
+    } else {
+	p = concatStr;
+        for (i = 0;  i < objc;  i++) {
+	    objPtr = objv[i];
+	    element = TclGetStringFromObj(objPtr, &elemLength);
+	    while ((elemLength > 0) && (isspace(UCHAR(*element)))) {
+	         element++;
+		 elemLength--;
+	    }
+
+	    /*
+	     * Trim trailing white space.  But, be careful not to trim
+	     * a space character if it is preceded by a backslash: in
+	     * this case it could be significant.
+	     */
+
+	    while ((elemLength > 0)
+		    && isspace(UCHAR(element[elemLength-1]))
+		    && ((elemLength < 2) || (element[elemLength-2] != '\\'))) {
+		elemLength--;
+	    }
+	    if (elemLength == 0) {
+	         continue;	/* nothing left of this element */
+	    }
+	    memcpy((VOID *) p, (VOID *) element, (size_t) elemLength);
+	    p += elemLength;
+	    *p = ' ';
+	    p++;
+	    finalSize += (elemLength + 1);
+        }
+        if (p != concatStr) {
+	    p[-1] = 0;
+	    finalSize -= 1;	/* we overwrote the final ' ' */
+        } else {
+	    *p = 0;
+        }
+    }
+    
+    TclNewObj(objPtr);
+    objPtr->bytes  = concatStr;
+    objPtr->length = finalSize;
+    return objPtr;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_StringMatch --
+ *
+ *	See if a particular string matches a particular pattern.
+ *
+ * Results:
+ *	The return value is 1 if string matches pattern, and
+ *	0 otherwise.  The matching operation permits the following
+ *	special characters in the pattern: *?\[] (see the manual
+ *	entry for details on what these mean).
+ *
+ * Side effects:
+ *	None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+Tcl_StringMatch(string, pattern)
+    char *string;		/* String. */
+    char *pattern;		/* Pattern, which may contain special
+				 * characters. */
+{
+    char c2;
+
+    while (1) {
+	/* See if we're at the end of both the pattern and the string.
+	 * If so, we succeeded.  If we're at the end of the pattern
+	 * but not at the end of the string, we failed.
+	 */
+	
+	if (*pattern == 0) {
+	    if (*string == 0) {
+		return 1;
+	    } else {
+		return 0;
+	    }
+	}
+	if ((*string == 0) && (*pattern != '*')) {
+	    return 0;
+	}
+
+	/* Check for a "*" as the next pattern character.  It matches
+	 * any substring.  We handle this by calling ourselves
+	 * recursively for each postfix of string, until either we
+	 * match or we reach the end of the string.
+	 */
+	
+	if (*pattern == '*') {
+	    pattern += 1;
+	    if (*pattern == 0) {
+		return 1;
+	    }
+	    while (1) {
+		if (Tcl_StringMatch(string, pattern)) {
+		    return 1;
+		}
+		if (*string == 0) {
+		    return 0;
+		}
+		string += 1;
+	    }
+	}
+    
+	/* Check for a "?" as the next pattern character.  It matches
+	 * any single character.
+	 */
+
+	if (*pattern == '?') {
+	    goto thisCharOK;
+	}
+
+	/* Check for a "[" as the next pattern character.  It is followed
+	 * by a list of characters that are acceptable, or by a range
+	 * (two characters separated by "-").
+	 */
+	
+	if (*pattern == '[') {
+	    pattern += 1;
+	    while (1) {
+		if ((*pattern == ']') || (*pattern == 0)) {
+		    return 0;
+		}
+		if (*pattern == *string) {
+		    break;
+		}
+		if (pattern[1] == '-') {
+		    c2 = pattern[2];
+		    if (c2 == 0) {
+			return 0;
+		    }
+		    if ((*pattern <= *string) && (c2 >= *string)) {
+			break;
+		    }
+		    if ((*pattern >= *string) && (c2 <= *string)) {
+			break;
+		    }
+		    pattern += 2;
+		}
+		pattern += 1;
+	    }
+	    while (*pattern != ']') {
+		if (*pattern == 0) {
+		    pattern--;
+		    break;
+		}
+		pattern += 1;
+	    }
+	    goto thisCharOK;
+	}
+    
+	/* If the next pattern character is '/', just strip off the '/'
+	 * so we do exact matching on the character that follows.
+	 */
+	
+	if (*pattern == '\\') {
+	    pattern += 1;
+	    if (*pattern == 0) {
+		return 0;
+	    }
+	}
+
+	/* There's no special character.  Just make sure that the next
+	 * characters of each string match.
+	 */
+	
+	if (*pattern != *string) {
+	    return 0;
+	}
+
+	thisCharOK: pattern += 1;
+	string += 1;
+    }
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_SetResult --
+ *
+ *	Arrange for "string" to be the Tcl return value.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	interp->result is left pointing either to "string" (if "copy" is 0)
+ *	or to a copy of string. Also, the object result is reset.
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+Tcl_SetResult(interp, string, freeProc)
+    Tcl_Interp *interp;		/* Interpreter with which to associate the
+				 * return value. */
+    char *string;		/* Value to be returned.  If NULL, the
+				 * result is set to an empty string. */
+    Tcl_FreeProc *freeProc;	/* Gives information about the string:
+				 * TCL_STATIC, TCL_VOLATILE, or the address
+				 * of a Tcl_FreeProc such as free. */
+{
+    Interp *iPtr = (Interp *) interp;
+    int length;
+    Tcl_FreeProc *oldFreeProc = iPtr->freeProc;
+    char *oldResult = iPtr->result;
+
+    if (string == NULL) {
+	iPtr->resultSpace[0] = 0;
+	iPtr->result = iPtr->resultSpace;
+	iPtr->freeProc = 0;
+    } else if (freeProc == TCL_VOLATILE) {
+	length = strlen(string);
+	if (length > TCL_RESULT_SIZE) {
+	    iPtr->result = (char *) ckalloc((unsigned) length+1);
+	    iPtr->freeProc = TCL_DYNAMIC;
+	} else {
+	    iPtr->result = iPtr->resultSpace;
+	    iPtr->freeProc = 0;
+	}
+	strcpy(iPtr->result, string);
+    } else {
+	iPtr->result = string;
+	iPtr->freeProc = freeProc;
+    }
+
+    /*
+     * If the old result was dynamically-allocated, free it up.  Do it
+     * here, rather than at the beginning, in case the new result value
+     * was part of the old result value.
+     */
+
+    if (oldFreeProc != 0) {
+	if ((oldFreeProc == TCL_DYNAMIC)
+		|| (oldFreeProc == (Tcl_FreeProc *) free)) {
+	    ckfree(oldResult);
+	} else {
+	    (*oldFreeProc)(oldResult);
+	}
+    }
+
+    /*
+     * Reset the object result since we just set the string result.
+     */
+
+    TclResetObjResult(iPtr);
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_GetStringResult --
+ *
+ *	Returns an interpreter's result value as a string.
+ *
+ * Results:
+ *	The interpreter's result as a string.
+ *
+ * Side effects:
+ *	If the string result is empty, the object result is moved to the
+ *	string result, then the object result is reset.
+ *
+ *----------------------------------------------------------------------
+ */
+
+char *
+Tcl_GetStringResult(interp)
+     Tcl_Interp *interp;	/* Interpreter whose result to return. */
+{
+    /*
+     * If the string result is empty, move the object result to the
+     * string result, then reset the object result.
+     * FAILS IF OBJECT RESULT'S STRING REPRESENTATION CONTAINS NULLS.
+     */
+    
+    if (*(interp->result) == 0) {
+	Tcl_SetResult(interp,
+	        TclGetStringFromObj(Tcl_GetObjResult(interp), (int *) NULL),
+	        TCL_VOLATILE);
+    }
+    return interp->result;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_SetObjResult --
+ *
+ *	Arrange for objPtr to be an interpreter's result value.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	interp->objResultPtr is left pointing to the object referenced
+ *	by objPtr. The object's reference count is incremented since
+ *	there is now a new reference to it. The reference count for any
+ *	old objResultPtr value is decremented. Also, the string result
+ *	is reset.
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+Tcl_SetObjResult(interp, objPtr)
+    Tcl_Interp *interp;		/* Interpreter with which to associate the
+				 * return object value. */
+    Tcl_Obj *objPtr;		/* Tcl object to be returned. If NULL, the
+				 * obj result is made an empty string
+				 * object. */
+{
+    Interp *iPtr = (Interp *) interp;
+    Tcl_Obj *oldObjResult = iPtr->objResultPtr;
+
+    iPtr->objResultPtr = objPtr;
+    Tcl_IncrRefCount(objPtr);	/* since interp result is a reference */
+
+    /*
+     * We wait until the end to release the old object result, in case
+     * we are setting the result to itself.
+     */
+    
+    TclDecrRefCount(oldObjResult);
+
+    /*
+     * Reset the string result since we just set the result object.
+     */
+
+    if (iPtr->freeProc != NULL) {
+	if ((iPtr->freeProc == TCL_DYNAMIC)
+	        || (iPtr->freeProc == (Tcl_FreeProc *) free)) {
+	    ckfree(iPtr->result);
+	} else {
+	    (*iPtr->freeProc)(iPtr->result);
+	}
+	iPtr->freeProc = 0;
+    }
+    iPtr->result = iPtr->resultSpace;
+    iPtr->resultSpace[0] = 0;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_GetObjResult --
+ *
+ *	Returns an interpreter's result value as a Tcl object. The object's
+ *	reference count is not modified; the caller must do that if it
+ *	needs to hold on to a long-term reference to it.
+ *
+ * Results:
+ *	The interpreter's result as an object.
+ *
+ * Side effects:
+ *	If the interpreter has a non-empty string result, the result object
+ *	is either empty or stale because some procedure set interp->result
+ *	directly. If so, the string result is moved to the result object
+ *	then the string result is reset.
+ *
+ *----------------------------------------------------------------------
+ */
+
+Tcl_Obj *
+Tcl_GetObjResult(interp)
+    Tcl_Interp *interp;		/* Interpreter whose result to return. */
+{
+    Interp *iPtr = (Interp *) interp;
+    Tcl_Obj *objResultPtr;
+    int length;
+
+    /*
+     * If the string result is non-empty, move the string result to the
+     * object result, then reset the string result.
+     */
+    
+    if (*(iPtr->result) != 0) {
+	TclResetObjResult(iPtr);
+	
+	objResultPtr = iPtr->objResultPtr;
+	length = strlen(iPtr->result);
+	TclInitStringRep(objResultPtr, iPtr->result, length);
+	
+	if (iPtr->freeProc != NULL) {
+	    if ((iPtr->freeProc == TCL_DYNAMIC)
+	            || (iPtr->freeProc == (Tcl_FreeProc *) free)) {
+		ckfree(iPtr->result);
+	    } else {
+		(*iPtr->freeProc)(iPtr->result);
+	    }
+	    iPtr->freeProc = 0;
+	}
+	iPtr->result = iPtr->resultSpace;
+	iPtr->resultSpace[0] = 0;
+    }
+    return iPtr->objResultPtr;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_AppendResult --
+ *
+ *	Append a variable number of strings onto the interpreter's string
+ *	result.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	The result of the interpreter given by the first argument is
+ *	extended by the strings given by the second and following arguments
+ *	(up to a terminating NULL argument).
+ *
+ *	If the string result is empty, the object result is moved to the
+ *	string result, then the object result is reset.
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+Tcl_AppendResult TCL_VARARGS_DEF(Tcl_Interp *,arg1)
+{
+    va_list argList;
+    Interp *iPtr;
+    char *string;
+    int newSpace;
+
+    /*
+     * If the string result is empty, move the object result to the
+     * string result, then reset the object result.
+     * FAILS IF OBJECT RESULT'S STRING REPRESENTATION CONTAINS NULLS.
+     */
+
+    iPtr = (Interp *) TCL_VARARGS_START(Tcl_Interp *,arg1,argList);
+    if (*(iPtr->result) == 0) {
+	Tcl_SetResult((Tcl_Interp *) iPtr,
+	        TclGetStringFromObj(Tcl_GetObjResult((Tcl_Interp *) iPtr),
+		        (int *) NULL),
+	        TCL_VOLATILE);
+    }
+    
+    /*
+     * Scan through all the arguments to see how much space is needed.
+     */
+
+    newSpace = 0;
+    while (1) {
+	string = va_arg(argList, char *);
+	if (string == NULL) {
+	    break;
+	}
+	newSpace += strlen(string);
+    }
+    va_end(argList);
+
+    /*
+     * If the append buffer isn't already setup and large enough to hold
+     * the new data, set it up.
+     */
+
+    if ((iPtr->result != iPtr->appendResult)
+	    || (iPtr->appendResult[iPtr->appendUsed] != 0)
+	    || ((newSpace + iPtr->appendUsed) >= iPtr->appendAvl)) {
+       SetupAppendBuffer(iPtr, newSpace);
+    }
+
+    /*
+     * Now go through all the argument strings again, copying them into the
+     * buffer.
+     */
+
+    TCL_VARARGS_START(Tcl_Interp *,arg1,argList);
+    while (1) {
+	string = va_arg(argList, char *);
+	if (string == NULL) {
+	    break;
+	}
+	strcpy(iPtr->appendResult + iPtr->appendUsed, string);
+	iPtr->appendUsed += strlen(string);
+    }
+    va_end(argList);
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_AppendElement --
+ *
+ *	Convert a string to a valid Tcl list element and append it to the
+ *	result (which is ostensibly a list).
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	The result in the interpreter given by the first argument is
+ *	extended with a list element converted from string. A separator
+ *	space is added before the converted list element unless the current
+ *	result is empty, contains the single character "{", or ends in " {".
+ *
+ *	If the string result is empty, the object result is moved to the
+ *	string result, then the object result is reset.
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+Tcl_AppendElement(interp, string)
+    Tcl_Interp *interp;		/* Interpreter whose result is to be
+				 * extended. */
+    char *string;		/* String to convert to list element and
+				 * add to result. */
+{
+    Interp *iPtr = (Interp *) interp;
+    char *dst;
+    int size;
+    int flags;
+
+    /*
+     * If the string result is empty, move the object result to the
+     * string result, then reset the object result.
+     * FAILS IF OBJECT RESULT'S STRING REPRESENTATION CONTAINS NULLS.
+     */
+
+    if (*(iPtr->result) == 0) {
+	Tcl_SetResult(interp,
+	        TclGetStringFromObj(Tcl_GetObjResult(interp), (int *) NULL),
+	        TCL_VOLATILE);
+    }
+
+    /*
+     * See how much space is needed, and grow the append buffer if
+     * needed to accommodate the list element.
+     */
+
+    size = Tcl_ScanElement(string, &flags) + 1;
+    if ((iPtr->result != iPtr->appendResult)
+	    || (iPtr->appendResult[iPtr->appendUsed] != 0)
+	    || ((size + iPtr->appendUsed) >= iPtr->appendAvl)) {
+       SetupAppendBuffer(iPtr, size+iPtr->appendUsed);
+    }
+
+    /*
+     * Convert the string into a list element and copy it to the
+     * buffer that's forming, with a space separator if needed.
+     */
+
+    dst = iPtr->appendResult + iPtr->appendUsed;
+    if (TclNeedSpace(iPtr->appendResult, dst)) {
+	iPtr->appendUsed++;
+	*dst = ' ';
+	dst++;
+    }
+    iPtr->appendUsed += Tcl_ConvertElement(string, dst, flags);
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * SetupAppendBuffer --
+ *
+ *	This procedure makes sure that there is an append buffer properly
+ *	initialized, if necessary, from the interpreter's result, and
+ *	that it has at least enough room to accommodate newSpace new
+ *	bytes of information.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static void
+SetupAppendBuffer(iPtr, newSpace)
+    Interp *iPtr;		/* Interpreter whose result is being set up. */
+    int newSpace;		/* Make sure that at least this many bytes
+				 * of new information may be added. */
+{
+    int totalSpace;
+
+    /*
+     * Make the append buffer larger, if that's necessary, then copy the
+     * result into the append buffer and make the append buffer the official
+     * Tcl result.
+     */
+
+    if (iPtr->result != iPtr->appendResult) {
+	/*
+	 * If an oversized buffer was used recently, then free it up
+	 * so we go back to a smaller buffer.  This avoids tying up
+	 * memory forever after a large operation.
+	 */
+
+	if (iPtr->appendAvl > 500) {
+	    ckfree(iPtr->appendResult);
+	    iPtr->appendResult = NULL;
+	    iPtr->appendAvl = 0;
+	}
+	iPtr->appendUsed = strlen(iPtr->result);
+    } else if (iPtr->result[iPtr->appendUsed] != 0) {
+	/*
+	 * Most likely someone has modified a result created by
+	 * Tcl_AppendResult et al. so that it has a different size.
+	 * Just recompute the size.
+	 */
+
+	iPtr->appendUsed = strlen(iPtr->result);
+    }
+    
+    totalSpace = newSpace + iPtr->appendUsed;
+    if (totalSpace >= iPtr->appendAvl) {
+	char *new;
+
+	if (totalSpace < 100) {
+	    totalSpace = 200;
+	} else {
+	    totalSpace *= 2;
+	}
+	new = (char *) ckalloc((unsigned) totalSpace);
+	strcpy(new, iPtr->result);
+	if (iPtr->appendResult != NULL) {
+	    ckfree(iPtr->appendResult);
+	}
+	iPtr->appendResult = new;
+	iPtr->appendAvl = totalSpace;
+    } else if (iPtr->result != iPtr->appendResult) {
+	strcpy(iPtr->appendResult, iPtr->result);
+    }
+    
+    Tcl_FreeResult((Tcl_Interp *) iPtr);
+    iPtr->result = iPtr->appendResult;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_FreeResult --
+ *
+ *	This procedure frees up the memory associated with an interpreter's
+ *	string result. It also resets the interpreter's result object.
+ *	Tcl_FreeResult is most commonly used when a procedure is about to
+ *	replace one result value with another.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	Frees the memory associated with interp's string result and sets
+ *	interp->freeProc to zero, but does not change interp->result or
+ *	clear error state. Resets interp's result object to an unshared
+ *	empty object.
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+Tcl_FreeResult(interp)
+    Tcl_Interp *interp;		/* Interpreter for which to free result. */
+{
+    Interp *iPtr = (Interp *) interp;
+    
+    if (iPtr->freeProc != NULL) {
+	if ((iPtr->freeProc == TCL_DYNAMIC)
+	        || (iPtr->freeProc == (Tcl_FreeProc *) free)) {
+	    ckfree(iPtr->result);
+	} else {
+	    (*iPtr->freeProc)(iPtr->result);
+	}
+	iPtr->freeProc = 0;
+    }
+    
+    TclResetObjResult(iPtr);
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_ResetResult --
+ *
+ *	This procedure resets both the interpreter's string and object
+ *	results.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	It resets the result object to an unshared empty object. It
+ *	then restores the interpreter's string result area to its default
+ *	initialized state, freeing up any memory that may have been
+ *	allocated. It also clears any error information for the interpreter.
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+Tcl_ResetResult(interp)
+    Tcl_Interp *interp;		/* Interpreter for which to clear result. */
+{
+    Interp *iPtr = (Interp *) interp;
+
+    TclResetObjResult(iPtr);
+    
+    Tcl_FreeResult(interp);
+    iPtr->result = iPtr->resultSpace;
+    iPtr->resultSpace[0] = 0;
+    
+    iPtr->flags &= ~(ERR_ALREADY_LOGGED | ERR_IN_PROGRESS | ERROR_CODE_SET);
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_SetErrorCode --
+ *
+ *	This procedure is called to record machine-readable information
+ *	about an error that is about to be returned.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	The errorCode global variable is modified to hold all of the
+ *	arguments to this procedure, in a list form with each argument
+ *	becoming one element of the list.  A flag is set internally
+ *	to remember that errorCode has been set, so the variable doesn't
+ *	get set automatically when the error is returned.
+ *
+ *----------------------------------------------------------------------
+ */
+	/* VARARGS2 */
+void
+Tcl_SetErrorCode TCL_VARARGS_DEF(Tcl_Interp *,arg1)
+{
+    va_list argList;
+    char *string;
+    int flags;
+    Interp *iPtr;
+
+    /*
+     * Scan through the arguments one at a time, appending them to
+     * $errorCode as list elements.
+     */
+
+    iPtr = (Interp *) TCL_VARARGS_START(Tcl_Interp *,arg1,argList);
+    flags = TCL_GLOBAL_ONLY | TCL_LIST_ELEMENT;
+    while (1) {
+	string = va_arg(argList, char *);
+	if (string == NULL) {
+	    break;
+	}
+	(void) Tcl_SetVar2((Tcl_Interp *) iPtr, "errorCode",
+		(char *) NULL, string, flags);
+	flags |= TCL_APPEND_VALUE;
+    }
+    va_end(argList);
+    iPtr->flags |= ERROR_CODE_SET;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_SetObjErrorCode --
+ *
+ *	This procedure is called to record machine-readable information
+ *	about an error that is about to be returned. The caller should
+ *	build a list object up and pass it to this routine.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	The errorCode global variable is modified to be the new value.
+ *	A flag is set internally to remember that errorCode has been
+ *	set, so the variable doesn't get set automatically when the
+ *	error is returned.
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+Tcl_SetObjErrorCode(interp, errorObjPtr)
+    Tcl_Interp *interp;
+    Tcl_Obj *errorObjPtr;
+{
+    Tcl_Obj *namePtr;
+    Interp *iPtr;
+    
+    namePtr = Tcl_NewStringObj("errorCode", -1);
+    iPtr = (Interp *) interp;
+    Tcl_ObjSetVar2(interp, namePtr, (Tcl_Obj *) NULL, errorObjPtr,
+	    TCL_GLOBAL_ONLY);
+    iPtr->flags |= ERROR_CODE_SET;
+    Tcl_DecrRefCount(namePtr);
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_RegExpCompile --
+ *
+ *	Compile a regular expression into a form suitable for fast
+ *	matching.  This procedure retains a small cache of pre-compiled
+ *	regular expressions in the interpreter, in order to avoid
+ *	compilation costs as much as possible.
+ *
+ * Results:
+ *	The return value is a pointer to the compiled form of string,
+ *	suitable for passing to Tcl_RegExpExec.  This compiled form
+ *	is only valid up until the next call to this procedure, so
+ *	don't keep these around for a long time!  If an error occurred
+ *	while compiling the pattern, then NULL is returned and an error
+ *	message is left in interp->result.
+ *
+ * Side effects:
+ *	The cache of compiled regexp's in interp will be modified to
+ *	hold information for string, if such information isn't already
+ *	present in the cache.
+ *
+ *----------------------------------------------------------------------
+ */
+
+Tcl_RegExp
+Tcl_RegExpCompile(interp, string)
+    Tcl_Interp *interp;			/* For use in error reporting. */
+    char *string;			/* String for which to produce
+					 * compiled regular expression. */
+{
+    Interp *iPtr = (Interp *) interp;
+    int i, length;
+    regexp *result;
+
+    length = strlen(string);
+    for (i = 0; i < NUM_REGEXPS; i++) {
+	if ((length == iPtr->patLengths[i])
+		&& (strcmp(string, iPtr->patterns[i]) == 0)) {
+	    /*
+	     * Move the matched pattern to the first slot in the
+	     * cache and shift the other patterns down one position.
+	     */
+
+	    if (i != 0) {
+		int j;
+		char *cachedString;
+
+		cachedString = iPtr->patterns[i];
+		result = iPtr->regexps[i];
+		for (j = i-1; j >= 0; j--) {
+		    iPtr->patterns[j+1] = iPtr->patterns[j];
+		    iPtr->patLengths[j+1] = iPtr->patLengths[j];
+		    iPtr->regexps[j+1] = iPtr->regexps[j];
+		}
+		iPtr->patterns[0] = cachedString;
+		iPtr->patLengths[0] = length;
+		iPtr->regexps[0] = result;
+	    }
+	    return (Tcl_RegExp) iPtr->regexps[0];
+	}
+    }
+
+    /*
+     * No match in the cache.  Compile the string and add it to the
+     * cache.
+     */
+
+    TclRegError((char *) NULL);
+    result = TclRegComp(string);
+    if (TclGetRegError() != NULL) {
+	Tcl_AppendResult(interp,
+	    "couldn't compile regular expression pattern: ",
+	    TclGetRegError(), (char *) NULL);
+	return NULL;
+    }
+    if (iPtr->patterns[NUM_REGEXPS-1] != NULL) {
+	ckfree(iPtr->patterns[NUM_REGEXPS-1]);
+	ckfree((char *) iPtr->regexps[NUM_REGEXPS-1]);
+    }
+    for (i = NUM_REGEXPS - 2; i >= 0; i--) {
+	iPtr->patterns[i+1] = iPtr->patterns[i];
+	iPtr->patLengths[i+1] = iPtr->patLengths[i];
+	iPtr->regexps[i+1] = iPtr->regexps[i];
+    }
+    iPtr->patterns[0] = (char *) ckalloc((unsigned) (length+1));
+    strcpy(iPtr->patterns[0], string);
+    iPtr->patLengths[0] = length;
+    iPtr->regexps[0] = result;
+    return (Tcl_RegExp) result;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_RegExpExec --
+ *
+ *	Execute the regular expression matcher using a compiled form
+ *	of a regular expression and save information about any match
+ *	that is found.
+ *
+ * Results:
+ *	If an error occurs during the matching operation then -1
+ *	is returned and interp->result contains an error message.
+ *	Otherwise the return value is 1 if a matching range is
+ *	found and 0 if there is no matching range.
+ *
+ * Side effects:
+ *	None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+Tcl_RegExpExec(interp, re, string, start)
+    Tcl_Interp *interp;		/* Interpreter to use for error reporting. */
+    Tcl_RegExp re;		/* Compiled regular expression;  must have
+				 * been returned by previous call to
+				 * Tcl_RegExpCompile. */
+    char *string;		/* String against which to match re. */
+    char *start;		/* If string is part of a larger string,
+				 * this identifies beginning of larger
+				 * string, so that "^" won't match. */
+{
+    int match;
+
+    regexp *regexpPtr = (regexp *) re;
+    TclRegError((char *) NULL);
+    match = TclRegExec(regexpPtr, string, start);
+    if (TclGetRegError() != NULL) {
+	Tcl_ResetResult(interp);
+	Tcl_AppendResult(interp, "error while matching regular expression: ",
+		TclGetRegError(), (char *) NULL);
+	return -1;
+    }
+    return match;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_RegExpRange --
+ *
+ *	Returns pointers describing the range of a regular expression match,
+ *	or one of the subranges within the match.
+ *
+ * Results:
+ *	The variables at *startPtr and *endPtr are modified to hold the
+ *	addresses of the endpoints of the range given by index.  If the
+ *	specified range doesn't exist then NULLs are returned.
+ *
+ * Side effects:
+ *	None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+Tcl_RegExpRange(re, index, startPtr, endPtr)
+    Tcl_RegExp re;		/* Compiled regular expression that has
+				 * been passed to Tcl_RegExpExec. */
+    int index;			/* 0 means give the range of the entire
+				 * match, > 0 means give the range of
+				 * a matching subrange.  Must be no greater
+				 * than NSUBEXP. */
+    char **startPtr;		/* Store address of first character in
+				 * (sub-) range here. */
+    char **endPtr;		/* Store address of character just after last
+				 * in (sub-) range here. */
+{
+    regexp *regexpPtr = (regexp *) re;
+
+    if (index >= NSUBEXP) {
+	*startPtr = *endPtr = NULL;
+    } else {
+	*startPtr = regexpPtr->startp[index];
+	*endPtr = regexpPtr->endp[index];
+    }
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_RegExpMatch --
+ *
+ *	See if a string matches a regular expression.
+ *
+ * Results:
+ *	If an error occurs during the matching operation then -1
+ *	is returned and interp->result contains an error message.
+ *	Otherwise the return value is 1 if "string" matches "pattern"
+ *	and 0 otherwise.
+ *
+ * Side effects:
+ *	None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+Tcl_RegExpMatch(interp, string, pattern)
+    Tcl_Interp *interp;		/* Used for error reporting. */
+    char *string;		/* String. */
+    char *pattern;		/* Regular expression to match against
+				 * string. */
+{
+    Tcl_RegExp re;
+
+    re = Tcl_RegExpCompile(interp, pattern);
+    if (re == NULL) {
+	return -1;
+    }
+    return Tcl_RegExpExec(interp, re, string, string);
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_DStringInit --
+ *
+ *	Initializes a dynamic string, discarding any previous contents
+ *	of the string (Tcl_DStringFree should have been called already
+ *	if the dynamic string was previously in use).
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	The dynamic string is initialized to be empty.
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+Tcl_DStringInit(dsPtr)
+    Tcl_DString *dsPtr;		/* Pointer to structure for dynamic string. */
+{
+    dsPtr->string = dsPtr->staticSpace;
+    dsPtr->length = 0;
+    dsPtr->spaceAvl = TCL_DSTRING_STATIC_SIZE;
+    dsPtr->staticSpace[0] = 0;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_DStringAppend --
+ *
+ *	Append more characters to the current value of a dynamic string.
+ *
+ * Results:
+ *	The return value is a pointer to the dynamic string's new value.
+ *
+ * Side effects:
+ *	Length bytes from string (or all of string if length is less
+ *	than zero) are added to the current value of the string. Memory
+ *	gets reallocated if needed to accomodate the string's new size.
+ *
+ *----------------------------------------------------------------------
+ */
+
+char *
+Tcl_DStringAppend(dsPtr, string, length)
+    Tcl_DString *dsPtr;		/* Structure describing dynamic string. */
+    CONST char *string;		/* String to append.  If length is -1 then
+				 * this must be null-terminated. */
+    int length;			/* Number of characters from string to
+				 * append.  If < 0, then append all of string,
+				 * up to null at end. */
+{
+    int newSize;
+    char *newString, *dst;
+    CONST char *end;
+
+    if (length < 0) {
+	length = strlen(string);
+    }
+    newSize = length + dsPtr->length;
+
+    /*
+     * Allocate a larger buffer for the string if the current one isn't
+     * large enough. Allocate extra space in the new buffer so that there
+     * will be room to grow before we have to allocate again.
+     */
+
+    if (newSize >= dsPtr->spaceAvl) {
+	dsPtr->spaceAvl = newSize*2;
+	newString = (char *) ckalloc((unsigned) dsPtr->spaceAvl);
+	memcpy((VOID *) newString, (VOID *) dsPtr->string,
+		(size_t) dsPtr->length);
+	if (dsPtr->string != dsPtr->staticSpace) {
+	    ckfree(dsPtr->string);
+	}
+	dsPtr->string = newString;
+    }
+
+    /*
+     * Copy the new string into the buffer at the end of the old
+     * one.
+     */
+
+    for (dst = dsPtr->string + dsPtr->length, end = string+length;
+	    string < end; string++, dst++) {
+	*dst = *string;
+    }
+    *dst = '\0';
+    dsPtr->length += length;
+    return dsPtr->string;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_DStringAppendElement --
+ *
+ *	Append a list element to the current value of a dynamic string.
+ *
+ * Results:
+ *	The return value is a pointer to the dynamic string's new value.
+ *
+ * Side effects:
+ *	String is reformatted as a list element and added to the current
+ *	value of the string.  Memory gets reallocated if needed to
+ *	accomodate the string's new size.
+ *
+ *----------------------------------------------------------------------
+ */
+
+char *
+Tcl_DStringAppendElement(dsPtr, string)
+    Tcl_DString *dsPtr;		/* Structure describing dynamic string. */
+    CONST char *string;		/* String to append.  Must be
+				 * null-terminated. */
+{
+    int newSize, flags;
+    char *dst, *newString;
+
+    newSize = Tcl_ScanElement(string, &flags) + dsPtr->length + 1;
+
+    /*
+     * Allocate a larger buffer for the string if the current one isn't
+     * large enough.  Allocate extra space in the new buffer so that there
+     * will be room to grow before we have to allocate again.
+     * SPECIAL NOTE: must use memcpy, not strcpy, to copy the string
+     * to a larger buffer, since there may be embedded NULLs in the
+     * string in some cases.
+     */
+
+    if (newSize >= dsPtr->spaceAvl) {
+	dsPtr->spaceAvl = newSize*2;
+	newString = (char *) ckalloc((unsigned) dsPtr->spaceAvl);
+	memcpy((VOID *) newString, (VOID *) dsPtr->string,
+		(size_t) dsPtr->length);
+	if (dsPtr->string != dsPtr->staticSpace) {
+	    ckfree(dsPtr->string);
+	}
+	dsPtr->string = newString;
+    }
+
+    /*
+     * Convert the new string to a list element and copy it into the
+     * buffer at the end, with a space, if needed.
+     */
+
+    dst = dsPtr->string + dsPtr->length;
+    if (TclNeedSpace(dsPtr->string, dst)) {
+	*dst = ' ';
+	dst++;
+	dsPtr->length++;
+    }
+    dsPtr->length += Tcl_ConvertElement(string, dst, flags);
+    return dsPtr->string;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_DStringSetLength --
+ *
+ *	Change the length of a dynamic string.  This can cause the
+ *	string to either grow or shrink, depending on the value of
+ *	length.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	The length of dsPtr is changed to length and a null byte is
+ *	stored at that position in the string.  If length is larger
+ *	than the space allocated for dsPtr, then a panic occurs.
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+Tcl_DStringSetLength(dsPtr, length)
+    Tcl_DString *dsPtr;		/* Structure describing dynamic string. */
+    int length;			/* New length for dynamic string. */
+{
+    if (length < 0) {
+	length = 0;
+    }
+    if (length >= dsPtr->spaceAvl) {
+	char *newString;
+
+	dsPtr->spaceAvl = length+1;
+	newString = (char *) ckalloc((unsigned) dsPtr->spaceAvl);
+
+	/*
+	 * SPECIAL NOTE: must use memcpy, not strcpy, to copy the string
+	 * to a larger buffer, since there may be embedded NULLs in the
+	 * string in some cases.
+	 */
+
+	memcpy((VOID *) newString, (VOID *) dsPtr->string,
+		(size_t) dsPtr->length);
+	if (dsPtr->string != dsPtr->staticSpace) {
+	    ckfree(dsPtr->string);
+	}
+	dsPtr->string = newString;
+    }
+    dsPtr->length = length;
+    dsPtr->string[length] = 0;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_DStringFree --
+ *
+ *	Frees up any memory allocated for the dynamic string and
+ *	reinitializes the string to an empty state.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	The previous contents of the dynamic string are lost, and
+ *	the new value is an empty string.
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+Tcl_DStringFree(dsPtr)
+    Tcl_DString *dsPtr;		/* Structure describing dynamic string. */
+{
+    if (dsPtr->string != dsPtr->staticSpace) {
+	ckfree(dsPtr->string);
+    }
+    dsPtr->string = dsPtr->staticSpace;
+    dsPtr->length = 0;
+    dsPtr->spaceAvl = TCL_DSTRING_STATIC_SIZE;
+    dsPtr->staticSpace[0] = 0;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_DStringResult --
+ *
+ *	This procedure moves the value of a dynamic string into an
+ *	interpreter as its string result. Afterwards, the dynamic string
+ *	is reset to an empty string.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	The string is "moved" to interp's result, and any existing
+ *	string result for interp is freed. dsPtr is reinitialized to
+ *	an empty string.
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+Tcl_DStringResult(interp, dsPtr)
+    Tcl_Interp *interp;		/* Interpreter whose result is to be reset. */
+    Tcl_DString *dsPtr;		/* Dynamic string that is to become the
+				 * result of interp. */
+{
+    Tcl_ResetResult(interp);
+    
+    if (dsPtr->string != dsPtr->staticSpace) {
+	interp->result = dsPtr->string;
+	interp->freeProc = TCL_DYNAMIC;
+    } else if (dsPtr->length < TCL_RESULT_SIZE) {
+	interp->result = ((Interp *) interp)->resultSpace;
+	strcpy(interp->result, dsPtr->string);
+    } else {
+	Tcl_SetResult(interp, dsPtr->string, TCL_VOLATILE);
+    }
+    
+    dsPtr->string = dsPtr->staticSpace;
+    dsPtr->length = 0;
+    dsPtr->spaceAvl = TCL_DSTRING_STATIC_SIZE;
+    dsPtr->staticSpace[0] = 0;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_DStringGetResult --
+ *
+ *	This procedure moves an interpreter's result into a dynamic string.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	The interpreter's string result is cleared, and the previous
+ *	contents of dsPtr are freed.
+ *
+ *	If the string result is empty, the object result is moved to the
+ *	string result, then the object result is reset.
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+Tcl_DStringGetResult(interp, dsPtr)
+    Tcl_Interp *interp;		/* Interpreter whose result is to be reset. */
+    Tcl_DString *dsPtr;		/* Dynamic string that is to become the
+				 * result of interp. */
+{
+    Interp *iPtr = (Interp *) interp;
+    
+    if (dsPtr->string != dsPtr->staticSpace) {
+	ckfree(dsPtr->string);
+    }
+
+    /*
+     * If the string result is empty, move the object result to the
+     * string result, then reset the object result.
+     * FAILS IF OBJECT RESULT'S STRING REPRESENTATION CONTAINS NULLS.
+     */
+
+    if (*(iPtr->result) == 0) {
+	Tcl_SetResult(interp,
+	        TclGetStringFromObj(Tcl_GetObjResult(interp), (int *) NULL),
+	        TCL_VOLATILE);
+    }
+
+    dsPtr->length = strlen(iPtr->result);
+    if (iPtr->freeProc != NULL) {
+	if ((iPtr->freeProc == TCL_DYNAMIC)
+		|| (iPtr->freeProc == (Tcl_FreeProc *) free)) {
+	    dsPtr->string = iPtr->result;
+	    dsPtr->spaceAvl = dsPtr->length+1;
+	} else {
+	    dsPtr->string = (char *) ckalloc((unsigned) (dsPtr->length+1));
+	    strcpy(dsPtr->string, iPtr->result);
+	    (*iPtr->freeProc)(iPtr->result);
+	}
+	dsPtr->spaceAvl = dsPtr->length+1;
+	iPtr->freeProc = NULL;
+    } else {
+	if (dsPtr->length < TCL_DSTRING_STATIC_SIZE) {
+	    dsPtr->string = dsPtr->staticSpace;
+	    dsPtr->spaceAvl = TCL_DSTRING_STATIC_SIZE;
+	} else {
+	    dsPtr->string = (char *) ckalloc((unsigned) (dsPtr->length + 1));
+	    dsPtr->spaceAvl = dsPtr->length + 1;
+	}
+	strcpy(dsPtr->string, iPtr->result);
+    }
+    
+    iPtr->result = iPtr->resultSpace;
+    iPtr->resultSpace[0] = 0;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_DStringStartSublist --
+ *
+ *	This procedure adds the necessary information to a dynamic
+ *	string (e.g. " {" to start a sublist.  Future element
+ *	appends will be in the sublist rather than the main list.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	Characters get added to the dynamic string.
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+Tcl_DStringStartSublist(dsPtr)
+    Tcl_DString *dsPtr;			/* Dynamic string. */
+{
+    if (TclNeedSpace(dsPtr->string, dsPtr->string + dsPtr->length)) {
+	Tcl_DStringAppend(dsPtr, " {", -1);
+    } else {
+	Tcl_DStringAppend(dsPtr, "{", -1);
+    }
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_DStringEndSublist --
+ *
+ *	This procedure adds the necessary characters to a dynamic
+ *	string to end a sublist (e.g. "}").  Future element appends
+ *	will be in the enclosing (sub)list rather than the current
+ *	sublist.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+Tcl_DStringEndSublist(dsPtr)
+    Tcl_DString *dsPtr;			/* Dynamic string. */
+{
+    Tcl_DStringAppend(dsPtr, "}", -1);
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_PrintDouble --
+ *
+ *	Given a floating-point value, this procedure converts it to
+ *	an ASCII string using.
+ *
+ * Results:
+ *	The ASCII equivalent of "value" is written at "dst".  It is
+ *	written using the current precision, and it is guaranteed to
+ *	contain a decimal point or exponent, so that it looks like
+ *	a floating-point value and not an integer.
+ *
+ * Side effects:
+ *	None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+Tcl_PrintDouble(interp, value, dst)
+    Tcl_Interp *interp;			/* Interpreter whose tcl_precision
+					 * variable used to be used to control
+					 * printing.  It's ignored now. */
+    double value;			/* Value to print as string. */
+    char *dst;				/* Where to store converted value;
+					 * must have at least TCL_DOUBLE_SPACE
+					 * characters. */
+{
+    char *p;
+
+    sprintf(dst, precisionFormat, value);
+
+    /*
+     * If the ASCII result looks like an integer, add ".0" so that it
+     * doesn't look like an integer anymore.  This prevents floating-point
+     * values from being converted to integers unintentionally.
+     */
+
+    for (p = dst; *p != 0; p++) {
+	if ((*p == '.') || (isalpha(UCHAR(*p)))) {
+	    return;
+	}
+    }
+    p[0] = '.';
+    p[1] = '0';
+    p[2] = 0;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclPrecTraceProc --
+ *
+ *	This procedure is invoked whenever the variable "tcl_precision"
+ *	is written.
+ *
+ * Results:
+ *	Returns NULL if all went well, or an error message if the
+ *	new value for the variable doesn't make sense.
+ *
+ * Side effects:
+ *	If the new value doesn't make sense then this procedure
+ *	undoes the effect of the variable modification.  Otherwise
+ *	it modifies the format string that's used by Tcl_PrintDouble.
+ *
+ *----------------------------------------------------------------------
+ */
+
+	/* ARGSUSED */
+char *
+TclPrecTraceProc(clientData, interp, name1, name2, flags)
+    ClientData clientData;	/* Not used. */
+    Tcl_Interp *interp;		/* Interpreter containing variable. */
+    char *name1;		/* Name of variable. */
+    char *name2;		/* Second part of variable name. */
+    int flags;			/* Information about what happened. */
+{
+    char *value, *end;
+    int prec;
+
+    /*
+     * If the variable is unset, then recreate the trace.
+     */
+
+    if (flags & TCL_TRACE_UNSETS) {
+	if ((flags & TCL_TRACE_DESTROYED) && !(flags & TCL_INTERP_DESTROYED)) {
+	    Tcl_TraceVar2(interp, name1, name2,
+		    TCL_GLOBAL_ONLY|TCL_TRACE_READS|TCL_TRACE_WRITES
+		    |TCL_TRACE_UNSETS, TclPrecTraceProc, clientData);
+	}
+	return (char *) NULL;
+    }
+
+    /*
+     * When the variable is read, reset its value from our shared
+     * value.  This is needed in case the variable was modified in
+     * some other interpreter so that this interpreter's value is
+     * out of date.
+     */
+
+    if (flags & TCL_TRACE_READS) {
+	Tcl_SetVar2(interp, name1, name2, precisionString,
+		flags & TCL_GLOBAL_ONLY);
+	return (char *) NULL;
+    }
+
+    /*
+     * The variable is being written.  Check the new value and disallow
+     * it if it isn't reasonable or if this is a safe interpreter (we
+     * don't want safe interpreters messing up the precision of other
+     * interpreters).
+     */
+
+    if (Tcl_IsSafe(interp)) {
+	Tcl_SetVar2(interp, name1, name2, precisionString,
+		flags & TCL_GLOBAL_ONLY);
+	return "can't modify precision from a safe interpreter";
+    }
+    value = Tcl_GetVar2(interp, name1, name2, flags & TCL_GLOBAL_ONLY);
+    if (value == NULL) {
+	value = "";
+    }
+    prec = strtoul(value, &end, 10);
+    if ((prec <= 0) || (prec > TCL_MAX_PREC) || (prec > 100) ||
+	    (end == value) || (*end != 0)) {
+	Tcl_SetVar2(interp, name1, name2, precisionString,
+		flags & TCL_GLOBAL_ONLY);
+	return "improper value for precision";
+    }
+    TclFormatInt(precisionString, prec);
+    sprintf(precisionFormat, "%%.%dg", prec);
+    return (char *) NULL;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclNeedSpace --
+ *
+ *	This procedure checks to see whether it is appropriate to
+ *	add a space before appending a new list element to an
+ *	existing string.
+ *
+ * Results:
+ *	The return value is 1 if a space is appropriate, 0 otherwise.
+ *
+ * Side effects:
+ *	None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+TclNeedSpace(start, end)
+    char *start;		/* First character in string. */
+    char *end;			/* End of string (place where space will
+				 * be added, if appropriate). */
+{
+    /*
+     * A space is needed unless either
+     * (a) we're at the start of the string, or
+     * (b) the trailing characters of the string consist of one or more
+     *     open curly braces preceded by a space or extending back to
+     *     the beginning of the string.
+     * (c) the trailing characters of the string consist of a space
+     *	   preceded by a character other than backslash.
+     */
+
+    if (end == start) {
+	return 0;
+    }
+    end--;
+    if (*end != '{') {
+	if (isspace(UCHAR(*end)) && ((end == start) || (end[-1] != '\\'))) {
+	    return 0;
+	}
+	return 1;
+    }
+    do {
+	if (end == start) {
+	    return 0;
+	}
+	end--;
+    } while (*end == '{');
+    if (isspace(UCHAR(*end))) {
+	return 0;
+    }
+    return 1;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclFormatInt --
+ *
+ *	This procedure formats an integer into a sequence of decimal digit
+ *	characters in a buffer. If the integer is negative, a minus sign is
+ *	inserted at the start of the buffer. A null character is inserted at
+ *	the end of the formatted characters. It is the caller's
+ *	responsibility to ensure that enough storage is available. This
+ *	procedure has the effect of sprintf(buffer, "%d", n) but is faster.
+ *
+ * Results:
+ *	An integer representing the number of characters formatted, not
+ *	including the terminating \0.
+ *
+ * Side effects:
+ *	The formatted characters are written into the storage pointer to
+ *	by the "buffer" argument.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+TclFormatInt(buffer, n)
+    char *buffer;		/* Points to the storage into which the
+				 * formatted characters are written. */
+    long n;			/* The integer to format. */
+{
+    long intVal;
+    int i;
+    int numFormatted, j;
+    char *digits = "0123456789";
+
+    /*
+     * Check first whether "n" is the maximum negative value. This is
+     * -2^(m-1) for an m-bit word, and has no positive equivalent;
+     * negating it produces the same value.
+     */
+
+    if (n == -n) {
+	sprintf(buffer, "%ld", n);
+	return strlen(buffer);
+    }
+
+    /*
+     * Generate the characters of the result backwards in the buffer.
+     */
+
+    intVal = (n < 0? -n : n);
+    i = 0;
+    buffer[0] = '\0';
+    do {
+	i++;
+	buffer[i] = digits[intVal % 10];
+	intVal = intVal/10;
+    } while (intVal > 0);
+    if (n < 0) {
+	i++;
+	buffer[i] = '-';
+    }
+    numFormatted = i;
+
+    /*
+     * Now reverse the characters.
+     */
+
+    for (j = 0;  j < i;  j++, i--) {
+	char tmp = buffer[i];
+	buffer[i] = buffer[j];
+	buffer[j] = tmp;
+    }
+    return numFormatted;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclLooksLikeInt --
+ *
+ *	This procedure decides whether the leading characters of a
+ *	string look like an integer or something else (such as a
+ *	floating-point number or string).
+ *
+ * Results:
+ *	The return value is 1 if the leading characters of p look
+ *	like a valid Tcl integer.  If they look like a floating-point
+ *	number (e.g. "e01" or "2.4"), or if they don't look like a
+ *	number at all, then 0 is returned.
+ *
+ * Side effects:
+ *	None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+TclLooksLikeInt(p)
+    char *p;			/* Pointer to string. */
+{
+    while (isspace(UCHAR(*p))) {
+	p++;
+    }
+    if ((*p == '+') || (*p == '-')) {
+	p++;
+    }
+    if (!isdigit(UCHAR(*p))) {
+	return 0;
+    }
+    p++;
+    while (isdigit(UCHAR(*p))) {
+	p++;
+    }
+    if ((*p != '.') && (*p != 'e') && (*p != 'E')) {
+	return 1;
+    }
+    return 0;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclGetIntForIndex --
+ *
+ *	This procedure returns an integer corresponding to the list index
+ *	held in a Tcl object. The Tcl object's value is expected to be
+ *	either an integer or the string "end". 
+ *
+ * Results:
+ *	The return value is normally TCL_OK, which means that the index was
+ *	successfully stored into the location referenced by "indexPtr".  If
+ *	the Tcl object referenced by "objPtr" has the value "end", the
+ *	value stored is "endValue". If "objPtr"s values is not "end" and
+ *	can not be converted to an integer, TCL_ERROR is returned and, if
+ *	"interp" is non-NULL, an error message is left in the interpreter's
+ *	result object.
+ *
+ * Side effects:
+ *	The object referenced by "objPtr" might be converted to an
+ *	integer object.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+TclGetIntForIndex(interp, objPtr, endValue, indexPtr)
+     Tcl_Interp *interp;	/* Interpreter to use for error reporting. 
+				 * If NULL, then no error message is left
+				 * after errors. */
+     Tcl_Obj *objPtr;		/* Points to an object containing either
+				 * "end" or an integer. */
+     int endValue;		/* The value to be stored at "indexPtr" if
+				 * "objPtr" holds "end". */
+     int *indexPtr;		/* Location filled in with an integer
+				 * representing an index. */
+{
+    Interp *iPtr = (Interp *) interp;
+    char *bytes;
+    int index, length, result;
+
+    /*
+     * THIS FAILS IF THE INDEX OBJECT'S STRING REP CONTAINS NULLS.
+     */
+    
+    if (objPtr->typePtr == &tclIntType) {
+	*indexPtr = (int)objPtr->internalRep.longValue;
+	return TCL_OK;
+    }
+    
+    bytes = TclGetStringFromObj(objPtr, &length);
+    if ((*bytes == 'e')
+	    && (strncmp(bytes, "end", (unsigned) length) == 0)) {
+	index = endValue;
+    } else {
+	result = Tcl_GetIntFromObj((Tcl_Interp *) NULL, objPtr, &index);
+	if (result != TCL_OK) {
+	    if (iPtr != NULL) {
+		Tcl_AppendStringsToObj(Tcl_GetObjResult(interp),
+			"bad index \"", bytes,
+			"\": must be integer or \"end\"", (char *) NULL);
+	    }
+	    return result;
+	}
+    }
+    *indexPtr = index;
+    return TCL_OK;
+}