/*
 * tclCompExpr.c --
 *
 *	This file contains the code to parse and compile Tcl expressions
 *	and implementations of the Tcl commands corresponding to expression
 *	operators, such as the command ::tcl::mathop::+ .
 *
 * Contributions from Don Porter, NIST, 2006-2007. (not subject to US copyright)
 *
 * See the file "license.terms" for information on usage and redistribution of
 * this file, and for a DISCLAIMER OF ALL WARRANTIES.
 *
 * RCS: @(#) $Id: tclCompExpr.c,v 1.94 2008/01/17 17:45:51 dgp Exp $
 */

#include "tclInt.h"
#include "tclCompile.h"		/* CompileEnv */

/*
 * Expression parsing takes place in the routine ParseExpr().  It takes a

	    }

	    /*
	     * Remaining LEAF cases may involve filling Tcl_Tokens, so
	     * make room for at least 2 more tokens.
	     */

	    if (parsePtr->numTokens+1 >= parsePtr->tokensAvailable) {
		TclExpandTokenArray(parsePtr);
	    }
	    wordIndex = parsePtr->numTokens;
	    tokenPtr = parsePtr->tokenPtr + wordIndex;
	    tokenPtr->type = TCL_TOKEN_WORD;
	    tokenPtr->start = start;
	    parsePtr->numTokens++;

	    switch (lexeme) {

	    scanned = TclParseAllWhiteSpace(start, numBytes);
	    start +=scanned;
	    numBytes -= scanned;

	    /* Reparse the literal to get pointers into source string */
	    scanned = ParseLexeme(start, numBytes, &lexeme, NULL);

	    if (parsePtr->numTokens + 1 >= parsePtr->tokensAvailable) {
		TclExpandTokenArray(parsePtr);
	    }
	    subExprTokenPtr = parsePtr->tokenPtr + parsePtr->numTokens;
	    subExprTokenPtr->type = TCL_TOKEN_SUB_EXPR;
	    subExprTokenPtr->start = start;
	    subExprTokenPtr->size = scanned;
	    subExprTokenPtr->numComponents = 1;
	    subExprTokenPtr[1].type = TCL_TOKEN_TEXT;
	    subExprTokenPtr[1].start = start;

	    if (tokenPtr->numComponents == tokenPtr[1].numComponents + 1) {

		/*
		 * Single element word.  Copy tokens and convert the leading
		 * token to TCL_TOKEN_SUB_EXPR.
		 */

		while (parsePtr->numTokens + toCopy - 1
			>= parsePtr->tokensAvailable) {
		    TclExpandTokenArray(parsePtr);
		}
		subExprTokenPtr = parsePtr->tokenPtr + parsePtr->numTokens;
		memcpy(subExprTokenPtr, tokenPtr,
			(size_t) toCopy * sizeof(Tcl_Token));
		subExprTokenPtr->type = TCL_TOKEN_SUB_EXPR;
		parsePtr->numTokens += toCopy;
	    } else {

		/* 
		 * Multiple element word.  Create a TCL_TOKEN_SUB_EXPR
		 * token to lead, with fields initialized from the leading
		 * token, then copy entire set of word tokens.
		 */

		while (parsePtr->numTokens + toCopy
			>= parsePtr->tokensAvailable) {
		    TclExpandTokenArray(parsePtr);
		}
		subExprTokenPtr = parsePtr->tokenPtr + parsePtr->numTokens;
		*subExprTokenPtr = *tokenPtr;
		subExprTokenPtr->type = TCL_TOKEN_SUB_EXPR;
		subExprTokenPtr->numComponents++;
		subExprTokenPtr++;
		memcpy(subExprTokenPtr, tokenPtr,
			(size_t) toCopy * sizeof(Tcl_Token));

		/*
		 * Verify space for the two leading Tcl_Tokens representing
		 * the subexpression rooted by this operator.  The first
		 * Tcl_Token will be of type TCL_TOKEN_SUB_EXPR; the second
		 * of type TCL_TOKEN_OPERATOR.
		 */

		if (parsePtr->numTokens + 1 >= parsePtr->tokensAvailable) {
		    TclExpandTokenArray(parsePtr);
		}
		subExprTokenIdx = parsePtr->numTokens;
		subExprTokenPtr = parsePtr->tokenPtr + subExprTokenIdx;
		parsePtr->numTokens += 2;
		subExprTokenPtr->type = TCL_TOKEN_SUB_EXPR;
		subExprTokenPtr[1].type = TCL_TOKEN_OPERATOR;

		/*