This is patch.2b1f to perl5.002beta1.

[p5sagit/p5-mst-13.2.git] / lib / TieHash.pm

package TieHash;
use Carp;

sub new {
    my $pkg = shift;
    $pkg->TIEHASH(@_);
}

# Grandfather "new"

sub TIEHASH {
    my $pkg = shift;
    if (defined &{"{$pkg}::new"}) {
	carp "WARNING: calling ${pkg}->new since ${pkg}->TIEHASH is missing"
	    if $^W;
	$pkg->new(@_);
    }
    else {
	croak "$pkg doesn't define a TIEHASH method";
    }
}

sub EXISTS {
    my $pkg = ref $_[0];
    croak "$pkg doesn't define an EXISTS method";
}

sub CLEAR {
    my $self = shift;
    my $key = $self->FIRSTKEY(@_);
    my @keys;

    while (defined $key) {
	push @keys, $key;
	$key = $self->NEXTKEY(@_, $key);
    }
    foreach $key (@keys) {
	$self->DELETE(@_, $key);
    }
}

# The TieHash::Std package implements standard perl hash behaviour.
# It exists to act as a base class for classes which only wish to
# alter some parts of their behaviour.

package TieHash::Std;
@ISA = qw(TieHash);

sub TIEHASH  { bless {}, $_[0] }
sub STORE    { $_[0]->{$_[1]} = $_[2] }
sub FETCH    { $_[0]->{$_[1]} }
sub FIRSTKEY { my $a = scalar keys %{$_[0]}; each %{$_[0]} }
sub NEXTKEY  { each %{$_[0]} }
sub EXISTS   { exists $_[0]->{$_[1]} }
sub DELETE   { delete $_[0]->{$_[1]} }
sub CLEAR    { %{$_[0]} = () }

1;