New subroutine Symbol::qualify_to_ref()

Subject: Re: select under use strict

On Tue, 11 Mar 1997 16:36:25 -0500 (EST), Trevor Blackwell <tlb@viaweb.com> said:
>
>   use strict;
>   syswrite(select,"",0) || warn("$!");
[...]
> yields:
>
>   Can't use string ("main::STDOUT") as a symbol ref [...]

It seems a reasonable candidate for a new function in Symbol.pm, a
function just like qualify() which returns a globref.  Here's an
implementation.  I'll send this in again after 5.004.  In the meanwhile
you could just put something like it in your own code.

Usage would be like

    syswrite ref_qualify(select), "foo\n", 4 or die $!;

p5p-msgid: pzlo7ut03b.fsf@eeyore.ibcinc.com

diff --git a/lib/Symbol.pm b/lib/Symbol.pm
index e40ae7b..38927d9 100644 (file)
--- a/lib/Symbol.pm
+++ b/lib/Symbol.pm
@@ -23,6 +23,10 @@ Symbol - manipulate Perl symbols and their names
     print qualify(\*x), "\n";              # returns \*x
     print qualify(\*x, "FOO"), "\n";       # returns \*x
 
+    use strict refs;
+    print { ref_qualify $fh } "foo!\n";
+    $ref = ref_qualify $name, $pkg;
+
 =head1 DESCRIPTION
 
 C<Symbol::gensym> creates an anonymous glob and returns a reference
@@ -44,6 +48,10 @@ Qualification applies only to symbol names (strings).  References are
 left unchanged under the assumption that they are glob references,
 which are qualified by their nature.
 
+C<Symbol::ref_qualify> is just like C<Symbol::qualify> except that it
+returns a glob ref rather than a symbol name.  You can use the result
+even if C<use strict 'refs'> is in effect.
+
 =cut
 
 BEGIN { require 5.002; }
@@ -51,7 +59,9 @@ BEGIN { require 5.002; }
 require Exporter;
 @ISA = qw(Exporter);
 
-@EXPORT = qw(gensym ungensym qualify);
+@EXPORT = qw(gensym ungensym qualify ref_qualify);
+
+$VERSION = 1.02;
 
 my $genpkg = "Symbol::";
 my $genseq = 0;
@@ -88,4 +98,8 @@ sub qualify ($;$) {
     $name;
 }
 
+sub ref_qualify ($;$) {
+    return \*{ qualify $_[0], @_ > 1 ? $_[1] : caller };
+}
+
 1;