NAME

Lazy::Iterator - Objects encapsulating a set of lazy evaluation functions.

VERSION

version 0.003

SYNOPSIS

  use Lazy::Iterator;

  my $lazy = Lazy::Iterator->new(sub { state $i++ });

  while (my $next = $lazy->get()) { print "$next\n"; sleep 1; }

DESCRIPTION

Objects encapsulating a set of lazy evaluation functions, meaning you can combine them using the l_* functions from Lazy::Util.

METHODS

Lazy::Iterator->new($source)

  my $lazy = Lazy::Iterator->new(sub { $i++ });

Lazy::Iterator->new takes a code reference which will be used as the source for all the values and returns a Lazy::Iterator object encapsulating that source.

The $source needs to be either a CODE reference, or a Scalar::Defer variable of type 0, provided you have Scalar::Defer available.

$lazy->exhausted()

  my $exhausted = $lazy->exhausted();

$lazy->exhausted() checks if there's any more values left in the source, and caches any such value for the next $lazy->get() call. It returns 0 if there are values left, and 1 if the source is exhausted.

An exhausted Lazy::Iterator object will always return undef from a $lazy->get() call.

$lazy->get()

  my $next = $lazy->get();

$lazy->get returns the next value from the source it encapsulates. When there are no more values it returns undef.

$lazy->get_all()

  my @crazy = $lazy->get_all();

$lazy->get_all returns all the values from the source, if it can. This has the potential to never return as well as running out of memory if given a source of infinite values.

NOTES

If Scalar::Defer is installed, it will assume that any variable of type 0 is a Scalar::Defer variable and will treat it as a source of values.

SEE ALSO

Lazy::Util

Scalar::Defer

AUTHOR

Andreas Guldstrand <andreas.guldstrand@gmail.com>

COPYRIGHT AND LICENSE

This software is Copyright (c) 2017 by Andreas Guldstrand.

This is free software, licensed under:

  The MIT (X11) License

cpanm Lazy::Util

perl -MCPAN -e shell
install Lazy::Util