NAME

Sub::Sequence - simplest, looping over an array in chunks

SYNOPSIS

use Sub::Sequence;

my @user_id_list = (1..10_000_000);

seq \@user_id_list, 50, sub {
    my $list = shift;

    my $in_id = join ',', map { int $_; } @{$list};
    # UPDATE table SET status=1 WHERE id IN ($id_cond)
    sleep 1;
};

DESCRIPTION

Sub::Sequence provides the function named 'seq'. You can treat an array with simple interface.

FUNCTIONS

seq($array_ref, $n, \&code)

This function calls \&code with split array. And \&code takes $n items at a time(also give $step_count and $offset).

use Sub::Sequence;
use Data::Dumper;

my $result = seq [1, 2, 3, 4, 5], 2, sub {
    my ($list, $step, $offset) = @_;
    # ... Do something ...
    return $offset;
};

warn Dumper($result); # [ 0, 2, 4 ]

NOTE: Return value of seq is the array reference of return values of \&code in scalar context. However, seq was called in the list context, then return value is the flatten list.

use Sub::Sequence;
use Data::Dumper;

# scalar context
my $foo = seq [1, 2, 3, 4, 5], 2, sub {
    my @list = @{ $_[0] };
    return \@list;
};
warn Dumper($foo); # [ [1, 2], [3, 4], [5] ]

# list context
my @bar = seq [1, 2, 3, 4, 5], 2, sub {
    my @list = @{ $_[0] };
    return \@list;
};
warn Dumper(\@bar); # [ 1, 2, 3, 4, 5 ]

REPOSITORY

Sub::Sequence is hosted on github <http://github.com/bayashi/Sub-Sequence>

AUTHOR

Dai Okabayashi <bayashi@cpan.org>

SEE ALSO

An interface of this module was inspired by Sub::Retry.

Also check similar modules, Iterator::GroupedRange and natatime method in List::MoreUtils.

Lastly, see benchmark.pl (Sub::Sequence vs splice vs natatime) in samples directory.

LICENSE

This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself. See perlartistic.