File Coverage

blib/lib/Seq/Iter.pm

Criterion	Covered	Total	%
statement	28	29	96.5
branch	7	10	70.0
condition			n/a
subroutine	6	6	100.0
pod	1	1	100.0
total	42	46	91.3

package Seq::Iter;

use 5.010001;
use strict;
use warnings;

use Exporter qw(import);

our $AUTHORITY = 'cpan:PERLANCAR'; # AUTHORITY
our $DATE = '2023-11-21'; # DATE
our $DIST = 'Seq-Iter'; # DIST
our $VERSION = '0.001'; # VERSION

our @EXPORT_OK = qw(seq_iter);

our $BUFFER_SIZE = 10;

sub seq_iter {
    my @orig_seq = @_;

    my $index = -1;
    my $index_coderef;
    my @gen_seq;
    sub {
        $index++;
        splice @gen_seq, $BUFFER_SIZE-1 if @gen_seq > $BUFFER_SIZE;

      RETRY:
        if (defined $index_coderef) {
            my $item = $orig_seq[$index_coderef]->($index, \@orig_seq, \@gen_seq);
            return unless defined $item;
            unshift @gen_seq, $item;
            return $item;
        } elsif ($index >= @orig_seq) {
            return;
        } else {
            my $item = $orig_seq[$index];
            if (ref $item eq 'CODE') {
                $index_coderef = $index;
                goto RETRY;
            } else {
                unshift @gen_seq, $item;
                return $item;
            }
        }
    };
}

1;
# ABSTRACT: Generate a coderef iterator from a sequence of items, the last of which can be a coderef to produce more items

__END__