NAME

Util::Underscore::ListUtils - Interface to List::Util and List::MoreUtils

VERSION

version v1.3.0

FUNCTION REFERENCE

$scalar = _::reduce { BLOCK } @list

wrapper for List::Util::reduce

$bool = _::any { PREDICATE } @list

wrapper for List::Util::any

$bool = _::all { PREDICATE } @list

wrapper for List::Util::all

$bool = _::none { PREDICATE } @list

wrapper for List::Util::none

$scalar = _::first { PREDICATE } @list

wrapper for List::MoreUtils::first_value

$int = _::first_index { PREDICATE } @list

wrapper for List::MoreUtils::first_index

$scalar = _::last { PREDICATE } @list

wrapper for List::MoreUtils::last_value

$int = _::last_index { PREDICATE } @list

wrapper for List::MoreUtils::last_index

$num = _::max @list

$str = _::max_str @list

wrappers for List::Util::max and List::Util::maxstr, respectively.

$num = _::min @list

$str = _::min_str @list

wrappers for List::Util::min and List::Util::minstr, respectively.

$scalar = _::max_by { BLOCK } @list

@list = _::max_by { BLOCK } @list

$scalar = _::max_str_by { BLOCK } @list

@list = _::max_str_by { BLOCK } @list

Finds the maximum element(s). However, not the elements themselves but the value returned by the code block is used for sorting. This makes it unnecessary to sort with a Schwartzian Transform.

This function is context dependent. In void context, it will return immediately.

The max_by variant compares sorting keys numerically, whereas max_str_by uses string comparison.

{ BLOCK }: the sorting key code block. The current element will be aliased to $_ inside the code block. The code inside the block should have no side effects, because it's not guaranteed how often the block will be executed.

@list: the list from which the maximum element is to be found

returns: In scalar context: returns the first maximum element, or undef if no elements are found. In list context: returns the maximum elements, or the empty list of no elements are found. The maximum elements are returned in order.

$scalar = _::min_by { BLOCK } @list

@list = _::min_by { BLOCK } @list

$scalar = _::min_str_by { BLOCK } @list

@list = _::min_str_by { BLOCK } @list

See _::max_by and _::max_str_by. These functions work equivalently, except that they return the minimum element(s).

$num = _::sum 0, @list

wrapper for List::Util::sum

$num = _::product @list

wrapper for List::Util::product

%kvlist = _::pairgrep { PREDICATE } %kvlist

wrapper for List::Util::pairgrep

($k, $v) = _::pairfirst { PREDICATE } %kvlist

wrapper for List::Util::pairfirst

%kvlist = _::pairmap { BLOCK } %kvlist

wrapper for List::Util::pairmap

@list = _::shuffle @list

wrapper for List::Util::shuffle

$iter = _::natatime $size, @list

wrapper for List::MoreUtils::natatime

@list = _::zip \@array1, \@array2, ...

wrapper for List::MoreUtils::zip

Unlike List::MoreUtils::zip, this function directly takes array references, and not array variables. It still uses the same implementation. This change makes it easier to work with anonymous arrayrefs, or other data that isn't already inside a named array variable.

@list = _::uniq @list

wrapper for List::MoreUtils::uniq

=@list = _::uniq_by { KEY } @list

Discards duplicate values, using a key function to determine equality. This can e.g. be used to deduplicate a set of objects, using the result of some method call to determine whether they're equivalent.

This function can only be used in list context.

{ KEY }: The function to produce an equality key. When called, the current element is passed in via the $_ variable. This function must return a value that can be used as a hash key, i.e. a string.

@list: A list of values to deduplicate.

returns: A list containing the first value of each key. In scalar context, returns the number of unique elements in the list.

%hash = _::classify { KEY } @list

Categorizes the input items according to the provided key function.

The behavior in void context is undefined.

{ KEY }: A key function returning a category name. The current item is passed in via $_. The return value must be usable as a hash key, i.e. be a string.

@list: The list of items to classify.

returns: A key-value-list of classified items, where each key is the category name, and each value is an array ref of items. In scalar context, a hashref of arrayrefs is returned instead, which prevents unnecessary copies.

@list = _::part { INDEX_FUNCTION } @list

wrapper for List::MoreUtils::part

$iter = _::each_array \@array1, \@array2, ...

wrapper for List::MoreUtils::each_arrayref

BUGS

Please report any bugs or feature requests on the bugtracker website https://github.com/latk/p5-Util-Underscore/issues

When submitting a bug or request, please include a test-file or a patch to an existing test-file that illustrates the bug or desired feature.

AUTHOR

Lukas Atkinson (cpan: AMON) <amon@cpan.org>

COPYRIGHT AND LICENSE

This software is copyright (c) 2014 by Lukas Atkinson.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.