package Symbol;

BEGIN { require 5.005; }

require Exporter;
@ISA = qw(Exporter);
@EXPORT = qw(gensym ungensym qualify qualify_to_ref);
@EXPORT_OK = qw(delete_package geniosym);

$VERSION = '1.07';

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 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 $pkg;
# Global names: special character, "^xyz", or other.
if ($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 {
$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;