Re: can't tie already tied scalar

[Peter Stephenson <Peter.Stephenson@xxxxxxx>]

On Thu, 16 Aug 2012 12:06:38 +0200
Thomas Moschny <thomas.moschny@xxxxxx> wrote:
> With versions after 4.3.11, doing
>  typeset -Tx FOO foo ; typeset -Tx FOO foo
> results in this error: typeset: can't tie already tied scalar: FOO
>
> This shouldn't fail, as long as as the same scalar is tied to the same
> array (with the same separator).

There didn't seem any obvious reason why it shouldn't be possible to
change the separator by this means.

Index: Doc/Zsh/builtins.yo
===================================================================
RCS file: /cvsroot/zsh/zsh/Doc/Zsh/builtins.yo,v
retrieving revision 1.138
diff -p -u -r1.138 builtins.yo
--- Doc/Zsh/builtins.yo	7 Mar 2012 06:10:42 -0000	1.138
+++ Doc/Zsh/builtins.yo	16 Aug 2012 12:52:59 -0000
@@ -1552,7 +1552,9 @@ an array to var(SCALAR) is an error, and
 sets it to be a single-element array.  Note that both `tt(typeset -xT ...)'
 and `tt(export -T ...)' work, but only the scalar will be marked for
 export.  Setting the value using the scalar version causes a split on all
-separators (which cannot be quoted).
+separators (which cannot be quoted).  It is possible to use the
+same two tied variables with a different separator character in which
+case the variables remain joined as before but the separator is changed.
 
 The tt(-g) (global) flag is treated specially: it means that any
 resulting parameter will not be restricted to local scope.  Note that this
Index: Src/builtin.c
===================================================================
RCS file: /cvsroot/zsh/zsh/Src/builtin.c,v
retrieving revision 1.259
diff -p -u -r1.259 builtin.c
--- Src/builtin.c	15 Jul 2012 18:06:41 -0000	1.259
+++ Src/builtin.c	16 Aug 2012 12:52:59 -0000
@@ -2449,7 +2449,20 @@ bin_typeset(char *name, char **argv, Opt
 	    && (locallevel == pm->level || !(on & PM_LOCAL))) {
 	    if (pm->node.flags & PM_TIED) {
 		unqueue_signals();
-		zerrnam(name, "can't tie already tied scalar: %s", asg0.name);
+		if (!strcmp(asg->name, pm->ename)) {
+		    /*
+		     * Already tied in the fashion requested.
+		     */
+		    struct tieddata *tdp = (struct tieddata*)pm->u.data;
+		    /* Update join character */
+		    tdp->joinchar = joinchar;
+		    if (asg0.value)
+			setsparam(asg0.name, ztrdup(asg0.value));
+		    return 0;
+		} else {
+		    zerrnam(name, "can't tie already tied scalar: %s",
+			    asg0.name);
+		}
 		return 1;
 	    }
 	    if (!asg0.value && !(PM_TYPE(pm->node.flags) & (PM_ARRAY|PM_HASHED)))
Index: Test/B02typeset.ztst
===================================================================
RCS file: /cvsroot/zsh/zsh/Test/B02typeset.ztst,v
retrieving revision 1.21
diff -p -u -r1.21 B02typeset.ztst
--- Test/B02typeset.ztst	5 Nov 2008 13:02:10 -0000	1.21
+++ Test/B02typeset.ztst	16 Aug 2012 12:52:59 -0000
@@ -459,3 +459,12 @@
  silent2(){ local silence; silent1; }
  silent2
 0:typeset -g should be silent even without TYPESET_SILENT
+
+ typeset -T TIED_SCALAR tied_array
+ TIED_SCALAR=foo:bar
+ print $tied_array
+ typeset -T TIED_SCALAR=goo:car tied_array
+ print $tied_array
+0:retying arrays to same array works
+>foo bar
+>goo car

-- 
Peter Stephenson <pws@xxxxxxx>            Software Engineer
Tel: +44 (0)1223 692070                   Cambridge Silicon Radio Limited
Churchill House, Cambridge Business Park, Cowley Road, Cambridge, CB4 0WZ, UK


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