X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FSymbol.pm;h=1e408b59f7162d775ef4ad19e7dc081f5964b7b6;hb=d87d3eede5d67a7d281a1d929949e466e06bc21a;hp=38927d995af2ad204285e78b72209b5643616dd9;hpb=578b087ab63db59886b8f9a1e8bebc8524523fa5;p=p5sagit%2Fp5-mst-13.2.git

diff --git a/lib/Symbol.pm b/lib/Symbol.pm
index 38927d9..1e408b5 100644
--- a/lib/Symbol.pm
+++ b/lib/Symbol.pm
@@ -15,8 +15,11 @@ Symbol - manipulate Perl symbols and their names
 
     ungensym $sym;      # no effect
 
-    print qualify("x"), "\n";              # "Test::x"
-    print qualify("x", "FOO"), "\n"        # "FOO::x"
+    # replace *FOO{IO} handle but not $FOO, %FOO, etc.
+    *FOO = geniosym;
+
+    print qualify("x"), "\n";              # "main::x"
+    print qualify("x", "FOO"), "\n";       # "FOO::x"
     print qualify("BAR::x"), "\n";         # "BAR::x"
     print qualify("BAR::x", "FOO"), "\n";  # "BAR::x"
     print qualify("STDOUT", "FOO"), "\n";  # "main::STDOUT" (global)
@@ -24,8 +27,12 @@ Symbol - manipulate Perl symbols and their names
     print qualify(\*x, "FOO"), "\n";       # returns \*x
 
     use strict refs;
-    print { ref_qualify $fh } "foo!\n";
-    $ref = ref_qualify $name, $pkg;
+    print { qualify_to_ref $fh } "foo!\n";
+    $ref = qualify_to_ref $name, $pkg;
+
+    use Symbol qw(delete_package);
+    delete_package('Foo::Bar');
+    print "deleted\n" unless exists $Foo::{'Bar::'};
 
 =head1 DESCRIPTION
 
@@ -37,31 +44,48 @@ 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;
 otherwise, it uses the package of its caller.  Regardless, global
-variable names (e.g. "STDOUT", "ENV", "SIG") are always qualfied with
+variable names (e.g. "STDOUT", "ENV", "SIG") are always qualified with
 "main::".
 
 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
+C<Symbol::qualify_to_ref> is just like C<Symbol::qualify> except that it
+returns a glob ref rather than a symbol name, so you can use the result
 even if C<use strict 'refs'> is in effect.
 
+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 5.002; }
+BEGIN { require 5.005; }
 
 require Exporter;
 @ISA = qw(Exporter);
+@EXPORT = qw(gensym ungensym qualify qualify_to_ref);
+@EXPORT_OK = qw(delete_package geniosym);
 
-@EXPORT = qw(gensym ungensym qualify ref_qualify);
-
-$VERSION = 1.02;
+$VERSION = '1.07';
 
 my $genpkg = "Symbol::";
 my $genseq = 0;
@@ -80,14 +104,23 @@ sub gensym () {
     $ref;
 }
 
+sub geniosym () {
+    my $sym = gensym();
+    # force the IO slot to be filled
+    select(select $sym);
+    *$sym{IO};
+}
+
 sub ungensym ($) {}
 
 sub qualify ($;$) {
     my ($name) = @_;
     if (!ref($name) && index($name, '::') == -1 && index($name, "'") == -1) {
 	my $pkg;
-	# Global names: special character, "^x", or other. 
-	if ($name =~ /^([^a-z])|(\^[a-z])$/i || $global{$name}) {
+	# Global names: special character, "^xyz", or other. 
+	if ($name =~ /^(([^a-z])|(\^[a-z_]+))\z/i || $global{$name}) {
+	    # RGS 2001-11-05 : translate leading ^X to control-char
+	    $name =~ s/^\^([a-z_])/'qq(\c'.$1.')'/eei;
 	    $pkg = "main";
 	}
 	else {
@@ -98,8 +131,40 @@ sub qualify ($;$) {
     $name;
 }
 
-sub ref_qualify ($;$) {
+sub qualify_to_ref ($;$) {
     return \*{ qualify $_[0], @_ > 1 ? $_[1] : caller };
 }
 
+#
+# of Safe.pm lineage
+#
+sub delete_package ($) {
+    my $pkg = shift;
+
+    # expand to full symbol table name if needed
+
+    unless ($pkg =~ /^main::.*::$/) {
+        $pkg = "main$pkg"	if	$pkg =~ /^::/;
+        $pkg = "main::$pkg"	unless	$pkg =~ /^main::/;
+        $pkg .= '::'		unless	$pkg =~ /::$/;
+    }
+
+    my($stem, $leaf) = $pkg =~ m/(.*::)(\w+::)$/;
+    my $stem_symtab = *{$stem}{HASH};
+    return unless defined $stem_symtab and exists $stem_symtab->{$leaf};
+
+
+    # free all the symbols in the package
+
+    my $leaf_symtab = *{$stem_symtab->{$leaf}}{HASH};
+    foreach my $name (keys %$leaf_symtab) {
+        undef *{$pkg . $name};
+    }
+
+    # delete the symbol table
+
+    %$leaf_symtab = ();
+    delete $stem_symtab->{$leaf};
+}
+
 1;