* Should declare -p add a new declaration inside a function?
@ 2008-09-13 14:52 Rocky Bernstein
2008-09-13 19:55 ` Peter Stephenson
0 siblings, 1 reply; 5+ messages in thread
From: Rocky Bernstein @ 2008-09-13 14:52 UTC (permalink / raw)
To: Zsh Hackers' List
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It appears that using "declare" or "typeset" with the -p (print) flag will
add a new declaration inside a function. Is this really desirable? It seems
to reduce the usefulness of -p.
Here's an example:
declare -a xx
xx=(an array)
bug() {
echo xx is \"${xx[@]}\" before \"declare -p xx\"
echo 'declare -p xx:'
declare -p xx
echo xx is now \"${xx[@]}\" in bug
echo '===='
}
bug
echo 'declare -p xx outside bug:'
declare -p xx
Running this produces:
xx is "an array" before "declare -p xx"
declare -p xx:
typeset xx=''
xx is now "" in bug
====
declare -p xx outside bug:
typeset -a xx
xx=(an array)
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^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Should declare -p add a new declaration inside a function?
2008-09-13 14:52 Should declare -p add a new declaration inside a function? Rocky Bernstein
@ 2008-09-13 19:55 ` Peter Stephenson
2008-09-14 0:48 ` Rocky Bernstein
0 siblings, 1 reply; 5+ messages in thread
From: Peter Stephenson @ 2008-09-13 19:55 UTC (permalink / raw)
To: Zsh Hackers' List
On Sat, 13 Sep 2008 10:52:35 -0400
"Rocky Bernstein" <rocky.bernstein@gmail.com> wrote:
> It appears that using "declare" or "typeset" with the -p (print) flag will
> add a new declaration inside a function. Is this really desirable? It seems
> to reduce the usefulness of -p.
That sure as heck looks like a bug to me. It shouldn't ever create
anything, even if the variable doesn't exist; it's purely for
information. I don't think "declare -p" has had much love and
attention; it doesn't look like it's ever worked with arguments
other than patterns (with -m).
Index: Src/builtin.c
===================================================================
RCS file: /cvsroot/zsh/zsh/Src/builtin.c,v
retrieving revision 1.205
diff -u -r1.205 builtin.c
--- Src/builtin.c 11 Sep 2008 17:14:39 -0000 1.205
+++ Src/builtin.c 13 Sep 2008 19:49:33 -0000
@@ -2473,10 +2473,17 @@
/* Take arguments literally. Don't glob */
while ((asg = getasg(*argv++))) {
- if (!typeset_single(name, asg->name,
- (Param) (paramtab == realparamtab ?
- gethashnode2(paramtab, asg->name) :
- paramtab->getnode(paramtab, asg->name)),
+ HashNode hn = (paramtab == realparamtab ?
+ gethashnode2(paramtab, asg->name) :
+ paramtab->getnode(paramtab, asg->name));
+ if (OPT_ISSET(ops,'p')) {
+ if (hn)
+ printparamnode(hn, printflags);
+ else
+ zwarnnam(name, "no such variable: %s", asg->name);
+ continue;
+ }
+ if (!typeset_single(name, asg->name, (Param)hn,
func, on, off, roff, asg->value, NULL,
ops, 0))
returnval = 1;
Index: Test/B02typeset.ztst
===================================================================
RCS file: /cvsroot/zsh/zsh/Test/B02typeset.ztst,v
retrieving revision 1.18
diff -u -r1.18 B02typeset.ztst
--- Test/B02typeset.ztst 16 Dec 2007 14:05:16 -0000 1.18
+++ Test/B02typeset.ztst 13 Sep 2008 19:49:33 -0000
@@ -444,3 +444,12 @@
0:Lower case conversion, does not apply to values used internally
>lower
>value of $lower
+
+ typeset -a array
+ array=(foo bar)
+ fn() { typeset -p array nonexistent; }
+ fn
+0:declare -p shouldn't create scoped values
+>typeset -a array
+>array=(foo bar)
+?fn:typeset: no such variable: nonexistent
--
Peter Stephenson <p.w.stephenson@ntlworld.com>
Web page now at http://homepage.ntlworld.com/p.w.stephenson/
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Should declare -p add a new declaration inside a function?
2008-09-13 19:55 ` Peter Stephenson
@ 2008-09-14 0:48 ` Rocky Bernstein
2008-09-15 8:53 ` Peter Stephenson
0 siblings, 1 reply; 5+ messages in thread
From: Rocky Bernstein @ 2008-09-14 0:48 UTC (permalink / raw)
To: Peter Stephenson; +Cc: Zsh Hackers' List
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Thanks. This helps a lot.
A couple things to consider. Right now if the variable is not declared,
declare -p returns 0. Should it be nonzero as is the case if you give a bad
option?
Is there a way to figure out or get a list of local variables versus
non-local variables versus global variables? By "local" I mean those that
were defined in the most recent scope and by "global" I mean those defined
outside of any function nesting, and by "non-local" I mean "not defined in
the immediate scope."
Thanks again
On Sat, Sep 13, 2008 at 3:55 PM, Peter Stephenson <
p.w.stephenson@ntlworld.com> wrote:
> On Sat, 13 Sep 2008 10:52:35 -0400
> "Rocky Bernstein" <rocky.bernstein@gmail.com> wrote:
> > It appears that using "declare" or "typeset" with the -p (print) flag
> will
> > add a new declaration inside a function. Is this really desirable? It
> seems
> > to reduce the usefulness of -p.
>
> That sure as heck looks like a bug to me. It shouldn't ever create
> anything, even if the variable doesn't exist; it's purely for
> information. I don't think "declare -p" has had much love and
> attention; it doesn't look like it's ever worked with arguments
> other than patterns (with -m).
>
> Index: Src/builtin.c
> ===================================================================
> RCS file: /cvsroot/zsh/zsh/Src/builtin.c,v
> retrieving revision 1.205
> diff -u -r1.205 builtin.c
> --- Src/builtin.c 11 Sep 2008 17:14:39 -0000 1.205
> +++ Src/builtin.c 13 Sep 2008 19:49:33 -0000
> @@ -2473,10 +2473,17 @@
>
> /* Take arguments literally. Don't glob */
> while ((asg = getasg(*argv++))) {
> - if (!typeset_single(name, asg->name,
> - (Param) (paramtab == realparamtab ?
> - gethashnode2(paramtab, asg->name) :
> - paramtab->getnode(paramtab,
> asg->name)),
> + HashNode hn = (paramtab == realparamtab ?
> + gethashnode2(paramtab, asg->name) :
> + paramtab->getnode(paramtab, asg->name));
> + if (OPT_ISSET(ops,'p')) {
> + if (hn)
> + printparamnode(hn, printflags);
> + else
> + zwarnnam(name, "no such variable: %s", asg->name);
> + continue;
> + }
> + if (!typeset_single(name, asg->name, (Param)hn,
> func, on, off, roff, asg->value, NULL,
> ops, 0))
> returnval = 1;
> Index: Test/B02typeset.ztst
> ===================================================================
> RCS file: /cvsroot/zsh/zsh/Test/B02typeset.ztst,v
> retrieving revision 1.18
> diff -u -r1.18 B02typeset.ztst
> --- Test/B02typeset.ztst 16 Dec 2007 14:05:16 -0000 1.18
> +++ Test/B02typeset.ztst 13 Sep 2008 19:49:33 -0000
> @@ -444,3 +444,12 @@
> 0:Lower case conversion, does not apply to values used internally
> >lower
> >value of $lower
> +
> + typeset -a array
> + array=(foo bar)
> + fn() { typeset -p array nonexistent; }
> + fn
> +0:declare -p shouldn't create scoped values
> +>typeset -a array
> +>array=(foo bar)
> +?fn:typeset: no such variable: nonexistent
>
>
> --
> Peter Stephenson <p.w.stephenson@ntlworld.com>
> Web page now at http://homepage.ntlworld.com/p.w.stephenson/
>
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^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Should declare -p add a new declaration inside a function?
2008-09-14 0:48 ` Rocky Bernstein
@ 2008-09-15 8:53 ` Peter Stephenson
2008-09-15 15:58 ` Rocky Bernstein
0 siblings, 1 reply; 5+ messages in thread
From: Peter Stephenson @ 2008-09-15 8:53 UTC (permalink / raw)
To: Zsh Hackers' List
On Sat, 13 Sep 2008 20:48:56 -0400
"Rocky Bernstein" <rocky.bernstein@gmail.com> wrote:
> A couple things to consider. Right now if the variable is not declared,
> declare -p returns 0. Should it be nonzero as is the case if you give a bad
> option?
Yes, I missed that the first time.
> Is there a way to figure out or get a list of local variables versus
> non-local variables versus global variables? By "local" I mean those that
> were defined in the most recent scope and by "global" I mean those defined
> outside of any function nesting, and by "non-local" I mean "not defined in
> the immediate scope."
You can use $parameters:
fn() {
local foo
print ${(k)parameters[(R)*local*]}
}
${(k)parameters[(R)^*local*]} (with extendedglob) gets you the global
parameters. There's no way of telling which function level a variable is
local at.
Index: Src/builtin.c
===================================================================
RCS file: /cvsroot/zsh/zsh/Src/builtin.c,v
retrieving revision 1.206
diff -u -r1.206 builtin.c
--- Src/builtin.c 13 Sep 2008 19:59:14 -0000 1.206
+++ Src/builtin.c 15 Sep 2008 08:52:40 -0000
@@ -2479,8 +2479,10 @@
if (OPT_ISSET(ops,'p')) {
if (hn)
printparamnode(hn, printflags);
- else
+ else {
zwarnnam(name, "no such variable: %s", asg->name);
+ returnval = 1;
+ }
continue;
}
if (!typeset_single(name, asg->name, (Param)hn,
Index: Test/B02typeset.ztst
===================================================================
RCS file: /cvsroot/zsh/zsh/Test/B02typeset.ztst,v
retrieving revision 1.19
diff -u -r1.19 B02typeset.ztst
--- Test/B02typeset.ztst 13 Sep 2008 19:59:14 -0000 1.19
+++ Test/B02typeset.ztst 15 Sep 2008 08:52:40 -0000
@@ -449,7 +449,7 @@
array=(foo bar)
fn() { typeset -p array nonexistent; }
fn
-0:declare -p shouldn't create scoped values
+1:declare -p shouldn't create scoped values
>typeset -a array
>array=(foo bar)
?fn:typeset: no such variable: nonexistent
--
Peter Stephenson <pws@csr.com> Software Engineer
CSR PLC, Churchill House, Cambridge Business Park, Cowley Road
Cambridge, CB4 0WZ, UK Tel: +44 (0)1223 692070
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Should declare -p add a new declaration inside a function?
2008-09-15 8:53 ` Peter Stephenson
@ 2008-09-15 15:58 ` Rocky Bernstein
0 siblings, 0 replies; 5+ messages in thread
From: Rocky Bernstein @ 2008-09-15 15:58 UTC (permalink / raw)
To: Peter Stephenson; +Cc: Zsh Hackers' List
[-- Attachment #1: Type: text/plain, Size: 2942 bytes --]
On Mon, Sep 15, 2008 at 4:53 AM, Peter Stephenson <pws@csr.com> wrote:
> On Sat, 13 Sep 2008 20:48:56 -0400
> "Rocky Bernstein" <rocky.bernstein@gmail.com> wrote:
> > A couple things to consider. Right now if the variable is not declared,
> > declare -p returns 0. Should it be nonzero as is the case if you give a
> bad
> > option?
>
> Yes, I missed that the first time.
Thanks. As many times in the past, this helps a lot. I had tried to parse
error output in a regular expression but that's problematic and not as
simple.
>
>
> > Is there a way to figure out or get a list of local variables versus
> > non-local variables versus global variables? By "local" I mean those that
> > were defined in the most recent scope and by "global" I mean those
> defined
> > outside of any function nesting, and by "non-local" I mean "not defined
> in
> > the immediate scope."
>
> You can use $parameters:
>
> fn() {
> local foo
> print ${(k)parameters[(R)*local*]}
> }
Interesting. This seems to show any variables defined local somewhere in the
call stack (not just the immediate one).
>
> ${(k)parameters[(R)^*local*]} (with extendedglob) gets you the global
> parameters. There's no way of telling which function level a variable is
> local at.
There are a number of possibilities for tracking what variable goes with
what stack frame. Probably best to defer deciding on how exactly to deal
with.
>
>
> Index: Src/builtin.c
> ===================================================================
> RCS file: /cvsroot/zsh/zsh/Src/builtin.c,v
> retrieving revision 1.206
> diff -u -r1.206 builtin.c
> --- Src/builtin.c 13 Sep 2008 19:59:14 -0000 1.206
> +++ Src/builtin.c 15 Sep 2008 08:52:40 -0000
> @@ -2479,8 +2479,10 @@
> if (OPT_ISSET(ops,'p')) {
> if (hn)
> printparamnode(hn, printflags);
> - else
> + else {
> zwarnnam(name, "no such variable: %s", asg->name);
> + returnval = 1;
> + }
> continue;
> }
> if (!typeset_single(name, asg->name, (Param)hn,
> Index: Test/B02typeset.ztst
> ===================================================================
> RCS file: /cvsroot/zsh/zsh/Test/B02typeset.ztst,v
> retrieving revision 1.19
> diff -u -r1.19 B02typeset.ztst
> --- Test/B02typeset.ztst 13 Sep 2008 19:59:14 -0000 1.19
> +++ Test/B02typeset.ztst 15 Sep 2008 08:52:40 -0000
> @@ -449,7 +449,7 @@
> array=(foo bar)
> fn() { typeset -p array nonexistent; }
> fn
> -0:declare -p shouldn't create scoped values
> +1:declare -p shouldn't create scoped values
> >typeset -a array
> >array=(foo bar)
> ?fn:typeset: no such variable: nonexistent
>
>
> --
> Peter Stephenson <pws@csr.com> Software Engineer
> CSR PLC, Churchill House, Cambridge Business Park, Cowley Road
> Cambridge, CB4 0WZ, UK Tel: +44 (0)1223 692070
>
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^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2008-09-15 15:59 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2008-09-13 14:52 Should declare -p add a new declaration inside a function? Rocky Bernstein
2008-09-13 19:55 ` Peter Stephenson
2008-09-14 0:48 ` Rocky Bernstein
2008-09-15 8:53 ` Peter Stephenson
2008-09-15 15:58 ` Rocky Bernstein
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