NAME
====

Seq::PreFetch - Asynchronously pre-fetch the next item of a Seq

SYNOPSIS
========

    use Seq::PreFetch;

    sub slow-and-lazy( --> Seq) {
      gather for 1..* {
        # a time expensive option... like sleep
        sleep 0.5;
        .take
      }
    }

    my $moment = now;
    for slow-and-lazy.&pre-fetch {
      .say;
      say "Delta: { now - $moment }";
      $moment = now;
      sleep 1;
    }

DESCRIPTION
===========

Seq::PreFetch asynchronously pre-fetches the next item of a Seq before you pull from the Seq. It provides the sub pre-fetch which wraps a Seq with a pre-fetching Seq.

This pattern allows you to consume one value from a Seq and begin concurrently calculating the next value of a Seq ready for the next time you need a value. Time efficiency gains can be made for operations where the time cost of a consuming loop is greater than the cost of starting a thread to pre-fetch.

As demonstrated in the synopsis example, The two operations do not block so the longer sleep in the loop defines the duration after the first iteration.

AUTHOR
======

Sam Gillespie <samgwise@gmail.com>

COPYRIGHT AND LICENSE
=====================

Copyright 2017 Sam Gillespie

This library is free software; you can redistribute it and/or modify it under the Artistic License 2.0.