# HG changeset patch
# User jwe
# Date 1068860433 0
# Node ID 1c0ec4705a5f64af646198c68c510d3b8818b3c0
# Parent  1e8d49b93fab1d37adc6dc01edf30bfacd0f0908
[project @ 2003-11-15 01:40:33 by jwe]

diff --git a/src/ChangeLog b/src/ChangeLog
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -3,6 +3,11 @@
 	* version.h (OCTAVE_VERSION): Now 2.1.51.
 	(OCTAVE_API_VERSION): Now api-v2.
 
+	* parse.y (cancel_obj_idx): New rule.
+	(postfix_expr, prefix_expr): Use begin_obj_idx after every
+	postfix_expr on RHS.  Use cancel_obj_idx as soon as possible for
+	cases where we are not working on an index expression.
+
 	* lex.l (maybe_unput_comma, handle_close_bracket):
 	Don't insert comma if we are looking at an object index and the
 	closest nesting level is a brace.
diff --git a/src/parse.y b/src/parse.y
--- a/src/parse.y
+++ b/src/parse.y
@@ -725,10 +725,21 @@
 		  { lexer_flags.looking_at_indirect_ref = true; }
 		;
 
+// Two more rules for lexical feedback.  To avoid reduce/reduce
+// conflicts, We use begin_obj_idx after every postfix_expr on the RHS
+// of a rule, then cancel that as soon as possible for cases when we
+// are not actually parsing an index expression.  Since all of those
+// cases are simple tokens that don't involve examining the value of 
+// lexer_flags.looking_at_object_index, I think we should be OK.
+
 begin_obj_idx	: // empty
 		  { lexer_flags.looking_at_object_index++; }
 		;
 
+cancel_obj_idx	: // empty
+		  { lexer_flags.looking_at_object_index--; }
+		;
+
 postfix_expr	: primary_expr
 		  { $$ = $1; }
 		| postfix_expr begin_obj_idx '(' ')'
@@ -751,21 +762,21 @@
 		    $$ = make_index_expression ($1, $4, '{');
 		    lexer_flags.looking_at_object_index--;
 		  }
-		| postfix_expr PLUS_PLUS
-		  { $$ = make_postfix_op (PLUS_PLUS, $1, $2); }
-		| postfix_expr MINUS_MINUS
-		  { $$ = make_postfix_op (MINUS_MINUS, $1, $2); }
-		| postfix_expr QUOTE
-		  { $$ = make_postfix_op (QUOTE, $1, $2); }
-		| postfix_expr TRANSPOSE
-		  { $$ = make_postfix_op (TRANSPOSE, $1, $2); }
-		| postfix_expr indirect_ref_op STRUCT_ELT
-		  { $$ = make_indirect_ref ($1, $3->text ()); }
-		| postfix_expr indirect_ref_op '(' expression ')'
-		  { $$ = make_indirect_ref ($1, $4); }
+		| postfix_expr begin_obj_idx PLUS_PLUS cancel_obj_idx
+		  { $$ = make_postfix_op (PLUS_PLUS, $1, $3); }
+		| postfix_expr begin_obj_idx MINUS_MINUS cancel_obj_idx
+		  { $$ = make_postfix_op (MINUS_MINUS, $1, $3); }
+		| postfix_expr begin_obj_idx QUOTE cancel_obj_idx
+		  { $$ = make_postfix_op (QUOTE, $1, $3); }
+		| postfix_expr begin_obj_idx TRANSPOSE cancel_obj_idx
+		  { $$ = make_postfix_op (TRANSPOSE, $1, $3); }
+		| postfix_expr begin_obj_idx indirect_ref_op cancel_obj_idx STRUCT_ELT
+		  { $$ = make_indirect_ref ($1, $5->text ()); }
+		| postfix_expr begin_obj_idx indirect_ref_op cancel_obj_idx '(' expression ')'
+		  { $$ = make_indirect_ref ($1, $6); }
 		;
 
-prefix_expr	: postfix_expr
+prefix_expr	: postfix_expr begin_obj_idx cancel_obj_idx
 		  { $$ = $1; }
 		| binary_expr
 		  { $$ = $1; }