Change 13765 by jhi@alpha on 2001/12/18 21:05:13
Subject: [PATCH] Suggested doc enhancement(?) to Exporter.pm
From: "Giroux, Mike (Exchange)" <[EMAIL PROTECTED]>
Date: Tue, 18 Dec 2001 12:05:40 -0500
Message-ID: <[EMAIL PROTECTED]>
Affected files ...
.... //depot/perl/lib/Exporter.pm#24 edit
Differences ...
==== //depot/perl/lib/Exporter.pm#24 (text) ====
Index: perl/lib/Exporter.pm
--- perl/lib/Exporter.pm.~1~ Tue Dec 18 14:15:05 2001
+++ perl/lib/Exporter.pm Tue Dec 18 14:15:05 2001
@@ -310,6 +310,40 @@
names being silently added to @EXPORT or @EXPORT_OK. Future versions
may make this a fatal error.
+=head2 Generating combined tags
+
+If several symbol categories exist in %EXPORT_TAGS, it's usually
+useful to create the utility ":all" to simplify "use" statements.
+
+The simplest way to do this is:
+
+ %EXPORT_TAGS = (foo => [qw(aa bb cc)], bar => [qw(aa cc dd)]);
+
+ # add all the other ":class" tags to the ":all" class,
+ # deleting duplicates
+ {
+ my %seen;
+
+ push @{$EXPORT_TAGS{all}},
+ grep {!$seen{$_}++} @{$EXPORT_TAGS{$_}} foreach keys %EXPORT_TAGS;
+ }
+
+CGI.pm creates an ":all" tag which contains some (but not really
+all) of its categories. That could be done with one small
+change:
+
+ # add some of the other ":class" tags to the ":all" class,
+ # deleting duplicates
+ {
+ my %seen;
+
+ push @{$EXPORT_TAGS{all}},
+ grep {!$seen{$_}++} @{$EXPORT_TAGS{$_}}
+ foreach qw/html2 html3 netscape form cgi internal/;
+ }
+
+Note that the tag names in %EXPORT_TAGS don't have the leading ':'.
+
=head2 C<AUTOLOAD>ed Constants
Many modules make use of C<AUTOLOAD>ing for constant subroutines to
End of Patch.
