package TGrep;
use strict;
use threads;
use Thread::Queue;

our $WORKERS = 4;

sub g_proxy {
    my( $code, $Qin, $Qout ) = @_;

    $Qout->enqueue( $code->() ? $_ : ()  ) while local $_ = $Qin->dequeue;
    $Qout->enqueue( undef );
}

sub tgrep(&@) {
    my $workers = $WORKERS;
    my $code = shift;
    my( $Qin, $Qout ) = map Thread::Queue->new, 1..2;
    async( \&g_proxy, $code, $Qin, $Qout )->detach for 1 .. $workers;
    $Qin->enqueue( map{ ref $_[0] ? @{ $_ } : $_ } @_ );
    $Qin->enqueue( (undef) x $workers );
    my @results;
    push @results, $_ while $_ = $Qout->dequeue;
    return wantarray ? @results : \@results;
}

sub import {
    no strict 'refs';
    my $pkg = caller;
    *{ $pkg . '::' . $_ } = *{ $_ } for qw[ tgrep ];
}

1;