A reduce sub in perl

reduce.pl

sub reduce (&;$@) {
    my $code = shift;
    my $f    = sub {
        my $base_val = shift;
        my $g        = sub {
            my $val = $base_val;
            for (@_) {
                local ( $a, $b ) = ( $val, $_ );
                $val = $code->( $val, $_ );
            }
            return $val;
        };
        @_ ? $g->(@_) : $g;
    };
    @_ ? $f->(@_) : $f;
}