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Diffstat (limited to 'contrib/perl5/lib/Symbol.pm')
-rw-r--r-- | contrib/perl5/lib/Symbol.pm | 146 |
1 files changed, 0 insertions, 146 deletions
diff --git a/contrib/perl5/lib/Symbol.pm b/contrib/perl5/lib/Symbol.pm deleted file mode 100644 index a95383a..0000000 --- a/contrib/perl5/lib/Symbol.pm +++ /dev/null @@ -1,146 +0,0 @@ -package Symbol; - -=head1 NAME - -Symbol - manipulate Perl symbols and their names - -=head1 SYNOPSIS - - use Symbol; - - $sym = gensym; - open($sym, "filename"); - $_ = <$sym>; - # etc. - - ungensym $sym; # no effect - - print qualify("x"), "\n"; # "Test::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) - print qualify(\*x), "\n"; # returns \*x - print qualify(\*x, "FOO"), "\n"; # returns \*x - - use strict refs; - 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 $Foo::{'Bar::'}; - - -=head1 DESCRIPTION - -C<Symbol::gensym> creates an anonymous glob and returns a reference -to it. Such a glob reference can be used as a file or directory -handle. - -For backward compatibility with older implementations that didn't -support anonymous globs, C<Symbol::ungensym> is also provided. -But it doesn't do anything. - -C<Symbol::qualify> turns unqualified symbol names into qualified -variable names (e.g. "myvar" -E<gt> "MyPackage::myvar"). If it is given a -second parameter, C<qualify> uses it as the default package; -otherwise, it uses the package of its caller. Regardless, global -variable names (e.g. "STDOUT", "ENV", "SIG") are always qualified with -"main::". - -Qualification applies only to symbol names (strings). References are -left unchanged under the assumption that they are glob references, -which are qualified by their nature. - -C<Symbol::qualify_to_ref> is just like C<Symbol::qualify> except that it -returns a glob ref rather than a symbol name, so you can use the result -even if C<use strict 'refs'> is in effect. - -C<Symbol::delete_package> wipes out a whole package namespace. Note -this routine is not exported by default--you may want to import it -explicitly. - -=cut - -BEGIN { require 5.002; } - -require Exporter; -@ISA = qw(Exporter); -@EXPORT = qw(gensym ungensym qualify qualify_to_ref); -@EXPORT_OK = qw(delete_package); - -$VERSION = 1.02; - -my $genpkg = "Symbol::"; -my $genseq = 0; - -my %global = map {$_ => 1} qw(ARGV ARGVOUT ENV INC SIG STDERR STDIN STDOUT); - -# -# Note that we never _copy_ the glob; we just make a ref to it. -# If we did copy it, then SVf_FAKE would be set on the copy, and -# glob-specific behaviors (e.g. C<*$ref = \&func>) wouldn't work. -# -sub gensym () { - my $name = "GEN" . $genseq++; - my $ref = \*{$genpkg . $name}; - delete $$genpkg{$name}; - $ref; -} - -sub ungensym ($) {} - -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}) { - $pkg = "main"; - } - else { - $pkg = (@_ > 1) ? $_[1] : caller; - } - $name = $pkg . "::" . $name; - } - $name; -} - -sub qualify_to_ref ($;$) { - 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; |