File Coverage

blib/lib/Continuation/Escape.pm

Criterion	Covered	Total	%
statement	26	26	100.0
branch	4	4	100.0
condition			n/a
subroutine	7	7	100.0
pod	0	1	0.0
total	37	38	97.3

package Continuation::Escape;
use strict;
use warnings;
use 5.8.0;
use base 'Exporter';
our @EXPORT = 'call_cc';
our $VERSION = '0.03';

use Scope::Upper qw/unwind HERE/;

# This registry is just so we can make sure that the user is NOT trying to save
# and run continuations later.
# Sorry if the name got you excited. :/
our %CONTINUATION_REGISTRY;

sub call_cc (&) {
    my $code = shift;

    my $escape_level = HERE;
    my $wantarray = wantarray;

    my $escape_continuation;
    $escape_continuation = sub {
        if (!exists($CONTINUATION_REGISTRY{$escape_continuation})) {
            require Carp;
            Carp::croak("Escape continuations are not usable outside of their original scope.");
        }

        unwind(($wantarray ? @_ : $_[0]) => $escape_level);
    };

    local $CONTINUATION_REGISTRY{$escape_continuation} = $escape_continuation;
    return $code->($escape_continuation);
}

1;

__END__