From bug-request at octave dot org Wed Feb  2 15:59:31 2005
Subject: Should be able to say 'for (k=1:N)'
From: "John W. Eaton" <jwe at bevo dot che dot wisc dot edu>
To: Julius Smith <jos at ccrma dot stanford dot edu>
Cc: bug at octave dot org
Date: Wed, 2 Feb 2005 15:57:21 -0600

On  2-Feb-2005, Julius Smith <jos at ccrma dot stanford dot edu> wrote:

| The octave session below illustrates a small parser inconsistency (see 
| fourth command line) that tends to bite C programmers. :-)
| 
|  > octave
| GNU Octave, version 2.1.64 (i686-pc-linux-gnu).
| ...
| 
| octave:1> 1:4
| ans =
| 
|    1  2  3  4
| 
| octave:2> (1:4)
| ans =
| 
|    1  2  3  4
| 
| octave:3> (k=1:4)
| k =
| 
|    1  2  3  4
| 
| octave:4> for (k=1:4), k, end
| parse error:
| 
|    syntax error
| 
|  >>> for (k=1:4), k, end
|                 ^
| 
| octave:4> for k=1:4, k, end
| k = 1
| k = 2
| k = 3
| k = 4
| octave:5> 

Please try the following patch.

Thanks,

jwe


src/ChangeLog:

2005-02-02  John W. Eaton  <jwe at octave dot org>

	* Makefile.in (parse.cc): Expect 12 shift/reduce conflicts.
	* parse.y (loop_command): Allow "for (k=1:10) ... endfor".


Index: src/Makefile.in
===================================================================
RCS file: /usr/local/cvsroot/octave/src/Makefile.in,v
retrieving revision 1.356
diff -u -r1.356 Makefile.in
--- src/Makefile.in	21 Jan 2005 03:32:09 -0000	1.356
+++ src/Makefile.in	2 Feb 2005 21:57:42 -0000
 at @ -513,7 +513,7 @@
 	 at $(top_srcdir)/move-if-change $@-t $@
 
 parse.cc : parse.y
-	 at echo "expect 11 shift/reduce conflicts"
+	 at echo "expect 12 shift/reduce conflicts"
 	$(YACC) $(YFLAGS) $<
 	 at $(top_srcdir)/move-if-change y.tab.c $(@F)
 
Index: src/parse.y
===================================================================
RCS file: /usr/local/cvsroot/octave/src/parse.y,v
retrieving revision 1.225
diff -u -r1.225 parse.y
--- src/parse.y	28 Dec 2004 01:59:05 -0000	1.225
+++ src/parse.y	2 Feb 2005 21:57:42 -0000
 at @ -1068,6 +1068,11 @@
 		    if (! ($$ = make_for_command ($1, $3, $5, $7, $8, $2)))
 		      ABORT_PARSE;
 		  }
+		| FOR stash_comment '(' assign_lhs '=' expression ')' opt_sep opt_list END
+		  {
+		    if (! ($$ = make_for_command ($1, $4, $6, $9, $10, $2)))
+		      ABORT_PARSE;
+		  }
 		;
 
 // =======



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