TIP#123 Implementation based on work by Arjen Markus. [Patch 655176]

1 files changed, 83 insertions, 7 deletions

diff --git a/generic/tclParseExpr.c b/generic/tclParseExpr.c
index bb88159..a0c0316 100644
--- a/generic/tclParseExpr.c
+++ b/generic/tclParseExpr.c
@@ -13,7 +13,7 @@
  * See the file "license.terms" for information on usage and redistribution
  * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tclParseExpr.c,v 1.17 2003/02/16 01:36:32 msofer Exp $
+ * RCS: @(#) $Id: tclParseExpr.c,v 1.18 2003/09/12 23:55:34 dkf Exp $
  */
 
 #include "tclInt.h"
@@ -130,6 +130,12 @@ typedef struct ParseInfo {
 #define STRNEQ		35
 
 /*
+ * Exponentiation operator:
+ */
+
+#define EXPON		36
+
+/*
  * Mapping from lexemes to strings; used for debugging messages. These
  * entries must match the order and number of the lexeme definitions above.
  */
@@ -140,7 +146,7 @@ static char *lexemeStrings[] = {
     "*", "/", "%", "+", "-",
     "<<", ">>", "<", ">", "<=", ">=", "==", "!=",
     "&", "^", "|", "&&", "||", "?", ":",
-    "!", "~", "eq", "ne",
+    "!", "~", "eq", "ne", "**"
 };
 
 /*
@@ -164,6 +170,7 @@ static int		ParseMultiplyExpr _ANSI_ARGS_((ParseInfo *infoPtr));
 static int		ParsePrimaryExpr _ANSI_ARGS_((ParseInfo *infoPtr));
 static int		ParseRelationalExpr _ANSI_ARGS_((ParseInfo *infoPtr));
 static int		ParseShiftExpr _ANSI_ARGS_((ParseInfo *infoPtr));
+static int		ParseExponentialExpr _ANSI_ARGS_((ParseInfo *infoPtr));
 static int		ParseUnaryExpr _ANSI_ARGS_((ParseInfo *infoPtr));
 static void		PrependSubExprTokens _ANSI_ARGS_((CONST char *op,
 				int opBytes, CONST char *src, int srcBytes,
@@ -976,7 +983,7 @@ ParseAddExpr(infoPtr)
  * ParseMultiplyExpr --
  *
  *	This procedure parses a Tcl multiply expression:
- *	multiplyExpr ::= unaryExpr {('*' | '/' | '%') unaryExpr}
+ *	multiplyExpr ::= exponentialExpr {('*' | '/' | '%') exponentialExpr}
  *
  * Results:
  *	The return value is TCL_OK on a successful parse and TCL_ERROR
@@ -1004,7 +1011,7 @@ ParseMultiplyExpr(infoPtr)
     srcStart = infoPtr->start;
     firstIndex = parsePtr->numTokens;
     
-    code = ParseUnaryExpr(infoPtr);
+    code = ParseExponentialExpr(infoPtr);
     if (code != TCL_OK) {
 	return code;
     }
@@ -1016,7 +1023,7 @@ ParseMultiplyExpr(infoPtr)
 	if (code != TCL_OK) {
 	    return code;
 	}
-	code = ParseUnaryExpr(infoPtr);
+	code = ParseExponentialExpr(infoPtr);
 	if (code != TCL_OK) {
 	    return code;
 	}
@@ -1035,6 +1042,69 @@ ParseMultiplyExpr(infoPtr)
 /*
  *----------------------------------------------------------------------
  *
+ * ParseExponentialExpr --
+ *
+ *	This procedure parses a Tcl exponential expression:
+ *	exponentialExpr ::= unaryExpr {'**' unaryExpr}
+ *
+ * Results:
+ *	The return value is TCL_OK on a successful parse and TCL_ERROR
+ *	on failure. If TCL_ERROR is returned, then the interpreter's result
+ *	contains an error message.
+ *
+ * Side effects:
+ *	If there is insufficient space in parsePtr to hold all the
+ *	information about the subexpression, then additional space is
+ *	malloc-ed.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static int
+ParseExponentialExpr(infoPtr)
+    ParseInfo *infoPtr;			/* Holds the parse state for the
+					 * expression being parsed. */
+{
+    Tcl_Parse *parsePtr = infoPtr->parsePtr;
+    int firstIndex, lexeme, code;
+    CONST char *srcStart, *operator;
+
+    HERE("exponentiateExpr", 12);
+    srcStart = infoPtr->start;
+    firstIndex = parsePtr->numTokens;
+
+    code = ParseUnaryExpr(infoPtr);
+    if (code != TCL_OK) {
+	return code;
+    }
+
+    lexeme = infoPtr->lexeme;
+    while (lexeme == EXPON) {
+	operator = infoPtr->start;
+	code = GetLexeme(infoPtr);	/* skip over ** */
+	if (code != TCL_OK) {
+	    return code;
+	}
+	code = ParseUnaryExpr(infoPtr);
+	if (code != TCL_OK) {
+	    return code;
+	}
+
+	/*
+	 * Generate tokens for the subexpression and ** operator.
+	 */
+
+	PrependSubExprTokens(operator, 2, srcStart,
+		(infoPtr->prevEnd - srcStart), firstIndex, infoPtr);
+	lexeme = infoPtr->lexeme;
+    }
+    return TCL_OK;
+}
+
+
+/*
+ *----------------------------------------------------------------------
+ *
  * ParseUnaryExpr --
  *
  *	This procedure parses a Tcl unary expression:
@@ -1062,7 +1132,7 @@ ParseUnaryExpr(infoPtr)
     int firstIndex, lexeme, code;
     CONST char *srcStart, *operator;
 
-    HERE("unaryExpr", 12);
+    HERE("unaryExpr", 13);
     srcStart = infoPtr->start;
     firstIndex = parsePtr->numTokens;
     
@@ -1132,7 +1202,7 @@ ParsePrimaryExpr(infoPtr)
      * We simply recurse on parenthesized subexpressions.
      */
 
-    HERE("primaryExpr", 13);
+    HERE("primaryExpr", 14);
     lexeme = infoPtr->lexeme;
     if (lexeme == OPEN_PAREN) {
 	code = GetLexeme(infoPtr); /* skip over the '(' */
@@ -1681,6 +1751,12 @@ GetLexeme(infoPtr)
 
 	case '*':
 	    infoPtr->lexeme = MULT;
+	    if ((infoPtr->lastChar - src)>1  &&  src[1]=='*') {
+		infoPtr->lexeme = EXPON;
+		infoPtr->size = 2;
+		infoPtr->next = src+2;
+		parsePtr->term = infoPtr->next;
+	    }
 	    return TCL_OK;
 
 	case '/':