X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FSymbol.pm;h=3bb5d9240c15c4319ab7dfdce7ef3b7526fe05ed;hb=ac0e6a2fd2970df72270aecb94d407fe170b43a7;hp=8739bd2b316e4cb1717796d3a9a67e667e761c05;hpb=c74f62b55c858d7cf9ed72589c05484ffce727b0;p=p5sagit%2Fp5-mst-13.2.git

diff --git a/lib/Symbol.pm b/lib/Symbol.pm
index 8739bd2..3bb5d92 100644
--- a/lib/Symbol.pm
+++ b/lib/Symbol.pm
@@ -15,6 +15,9 @@ Symbol - manipulate Perl symbols and their names
 
     ungensym $sym;      # no effect
 
+    # replace *FOO{IO} handle but not $FOO, %FOO, etc.
+    *FOO = geniosym;
+
     print qualify("x"), "\n";              # "Test::x"
     print qualify("x", "FOO"), "\n"        # "FOO::x"
     print qualify("BAR::x"), "\n";         # "BAR::x"
@@ -31,7 +34,6 @@ Symbol - manipulate Perl symbols and their names
     delete_package('Foo::Bar');
     print "deleted\n" unless exists $Foo::{'Bar::'};
 
-
 =head1 DESCRIPTION
 
 C<Symbol::gensym> creates an anonymous glob and returns a reference
@@ -42,6 +44,10 @@ For backward compatibility with older implementations that didn't
 support anonymous globs, C<Symbol::ungensym> is also provided.
 But it doesn't do anything.
 
+C<Symbol::geniosym> creates an anonymous IO handle.  This can be
+assigned into an existing glob without affecting the non-IO portions
+of the glob.
+
 C<Symbol::qualify> turns unqualified symbol names into qualified
 variable names (e.g. "myvar" -E<gt> "MyPackage::myvar").  If it is given a
 second parameter, C<qualify> uses it as the default package;
@@ -61,6 +67,15 @@ C<Symbol::delete_package> wipes out a whole package namespace.  Note
 this routine is not exported by default--you may want to import it
 explicitly.
 
+=head1 BUGS
+
+C<Symbol::delete_package> is a bit too powerful. It undefines every symbol that
+lives in the specified package. Since perl, for performance reasons, does not
+perform a symbol table lookup each time a function is called or a global
+variable is accessed, some code that has already been loaded and that makes use
+of symbols in package C<Foo> may stop working after you delete C<Foo>, even if
+you reload the C<Foo> module afterwards.
+
 =cut
 
 BEGIN { require 5.005; }
@@ -68,9 +83,9 @@ BEGIN { require 5.005; }
 require Exporter;
 @ISA = qw(Exporter);
 @EXPORT = qw(gensym ungensym qualify qualify_to_ref);
-@EXPORT_OK = qw(delete_package);
+@EXPORT_OK = qw(delete_package geniosym);
 
-$VERSION = 1.04;
+$VERSION = '1.06';
 
 my $genpkg = "Symbol::";
 my $genseq = 0;
@@ -89,6 +104,13 @@ sub gensym () {
     $ref;
 }
 
+sub geniosym () {
+    my $sym = gensym();
+    # force the IO slot to be filled
+    select(select $sym);
+    *$sym{IO};
+}
+
 sub ungensym ($) {}
 
 sub qualify ($;$) {