* generic/tclParseExpr.c: Completely new expression parser

        that builds a parse tree instead of operating with deep recursion.
        This corrects reports of stack-blowing crashes parsing long
        expressions [Bug 906201] and replaces a fundamentally O(N^2)
        algorithm with an O(N) one [RFE 903765].  The new parser is better
        able to generate error messages that clearly report both the nature
        and context of the syntax error [Bugs 1029267, 1381715].  For now,
        the code for the old parser is still present and can be activated
        with a "#define OLD_EXPR_PARSER 1".  This is for the sake of a clean
        implementation patch, and for ease of benchmarking.  The new parser
        is non-recursive, so much lighter in stack consumption, but it
        does use more heap, so there may be cases where parsing of long
        expressions that succeeded with the old parser will lead to out
        of memory panics with the new one.  There are still more improvements
        possible on that point, though significant progress may require
        changes to the Tcl_Token specifications documented for the public
        Tcl_Parse*() routines.
        ***POTENTIAL INCOMPATIBILITY*** for any callers that rely on the
        exact (usually terrible) error messages generated by the old parser.
        This includes a large number of tests in the test suite.

        * generic/tclInt.h:             Replaced TclParseWhiteSpace() with
        * generic/tclParse.c:           TclParseAllWhiteSpace() which is what
        * generic/tclParseExpr.c:       all the callers really needed.
        Breaking whitespace runs at newlines is useful only to the command
        parsing function, and it can call the file scoped routine
        ParseWhiteSpace() to do that.

        * tests/expr-old.test:  Removed knownBug constraints that masked
        * tests/expr.test:      failures due to revised error messages.
        * tests/parseExpr.test:

1 files changed, 34 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index 4f125c0..b2b53d1 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,37 @@
+2006-07-05  Don Porter  <dgp@users.sourceforge.net>
+
+	* generic/tclParseExpr.c:	Completely new expression parser
+	that builds a parse tree instead of operating with deep recursion.
+	This corrects reports of stack-blowing crashes parsing long
+	expressions [Bug 906201] and replaces a fundamentally O(N^2)
+	algorithm with an O(N) one [RFE 903765].  The new parser is better
+	able to generate error messages that clearly report both the nature
+	and context of the syntax error [Bugs 1029267, 1381715].  For now,
+	the code for the old parser is still present and can be activated
+	with a "#define OLD_EXPR_PARSER 1".  This is for the sake of a clean
+	implementation patch, and for ease of benchmarking.  The new parser
+	is non-recursive, so much lighter in stack consumption, but it
+	does use more heap, so there may be cases where parsing of long
+	expressions that succeeded with the old parser will lead to out
+	of memory panics with the new one.  There are still more improvements
+	possible on that point, though significant progress may require
+	changes to the Tcl_Token specifications documented for the public
+	Tcl_Parse*() routines.
+	***POTENTIAL INCOMPATIBILITY*** for any callers that rely on the
+	exact (usually terrible) error messages generated by the old parser.
+	This includes a large number of tests in the test suite.
+
+	* generic/tclInt.h:		Replaced TclParseWhiteSpace() with
+	* generic/tclParse.c:		TclParseAllWhiteSpace() which is what
+	* generic/tclParseExpr.c:	all the callers really needed.
+	Breaking whitespace runs at newlines is useful only to the command
+	parsing function, and it can call the file scoped routine
+	ParseWhiteSpace() to do that.
+
+	* tests/expr-old.test:	Removed knownBug constraints that masked
+	* tests/expr.test:	failures due to revised error messages.
+	* tests/parseExpr.test:
+
 2006-06-20  Don Porter  <dgp@users.sourceforge.net>
 
 	* generic/tclIOUtil.c:	Changed default configuration to