Data::Perl::Role::Collection::Array(3p)

NAME
Data::Perl::Role::Collection::Array - Wrapping class for Perl's built in array structure.

VERSION
version 0.002011

SYNOPSIS
  use Data::Perl qw/array/;

  my $array = array(1, 2, 3);

  $array->push(5);

  $array->grep(sub { $_ > 2 })->map(sub { $_ ** 2 })->elements; # (3, 5);

DESCRIPTION
This class provides a wrapper and methods for interacting with an array. All methods that return a list do so via a Data::Perl::Collection::Array object.

PROVIDED METHODS

new($value, $value, ....)
    Constructs a new Data::Perl::Collection::Array object initialized with passed in values, and returns it.

count
    Returns the number of elements in the array.

      $stuff = Data::Perl::Collection::Array->new(qw/foo bar baz boo/);

      print $stuff->count; # prints 4

    This method does not accept any arguments.

is_empty
    Returns a boolean value that is true when the array has no elements.

      $stuff->is_empty ? die "No options!\n" : print "Good boy.\n";

    This method does not accept any arguments.

elements/all
    Returns all of the elements of the array as an array (not an array reference).

      my @options = $stuff->elements;
      print "@options\n";    # prints "foo bar baz boo"

    This method does not accept any arguments.

get($index)
    Returns an element of the array by its index. You can also use negative index numbers, just as with Perl's core array handling.

      my $option = $stuff->get(1);
      print "$option\n";    # prints "bar"

    If the specified element does not exist, this will return "undef".

    This method accepts just one argument.

pop Just like Perl's builtin "pop".

    This method does not accept any arguments.

push($value1, $value2, value3 ...)
    Just like Perl's builtin "push". Returns the number of elements in the new array.

    This method accepts any number of arguments.

shift
    Just like Perl's builtin "shift".

    This method does not accept any arguments.

unshift($value1, $value2, value3 ...)
    Just like Perl's builtin "unshift". Returns the number of elements in the new array.

    This method accepts any number of arguments.

splice($offset, $length, @values)
    Just like Perl's builtin "splice". In scalar context, this returns the last element removed, or "undef" if no elements were removed. In list context, this returns all the elements removed from the array, wrapped in a Collection::Array object.

    This method requires at least one argument.

first( sub { ... } )
    This method returns the first matching item in the array, just like List::Util's "first" function. The matching is done with a subroutine reference you pass to this method. The subroutine will be called against each element in the array until one matches or all elements have been checked.

      my $found = $stuff->find_option( sub {/^b/} );
      print "$found\n";    # prints "bar"

    This method requires a single argument.

first_index( sub { ... } )
    This method returns the index of the first matching item in the array, just like List::MoreUtils's "first_index" function. The matching is done with a subroutine reference you pass to this method. The subroutine will be called against each element in the array until one matches or all elements have been checked.

    This method requires a single argument.

grep( sub { ... } )
    This method returns every element matching a given criteria, just like Perl's core "grep" function. This method requires a subroutine which implements the matching logic. The returned list is provided as a Collection::Array object.

      my @found = $stuff->grep( sub {/^b/} );
      print "@found\n";    # prints "bar baz boo"

    This method requires a single argument.

map( sub { ... } )
    This method transforms every element in the array and returns a new array, just like Perl's core "map" function. This method requires a subroutine which implements the transformation. The returned list is provided as a Collection::Array object.

      my @mod_options = $stuff->map( sub { $_ . "-tag" } );
      print "@mod_options\n";    # prints "foo-tag bar-tag baz-tag boo-tag"

    This method requires a single argument.

reduce( sub { ... } )
    This method turns an array into a single value, by passing a function the value so far and the next value in the array, just like List::Util's "reduce" function. The reducing is done with a subroutine reference you pass to this method.

      my $found = $stuff->reduce( sub { $_[0] . $_[1] } );
      print "$found\n";    # prints "foobarbazboo"

    This method requires a single argument.

sort
sort( sub { ... } )
    Returns the elements of the array in sorted order.

    You can provide an optional subroutine reference to sort with (as you can with Perl's core "sort" function). However, instead of using $a and $b in this subroutine, you will need to use $_[0] and $_[1]. The returned list is provided as a Collection::Array object.

      # ascending ASCIIbetical
      my @sorted = $stuff->sort();

      # Descending alphabetical order
      my @sorted_options = $stuff->sort( sub { lc $_[1] cmp lc $_[0] } );
      print "@sorted_options\n";    # prints "foo boo baz bar"

    This method accepts a single argument.

sort_in_place
sort_in_place( sub { ... } )
    Sorts the array in place, modifying the value of the attribute.

    You can provide an optional subroutine reference to sort with (as you can with Perl's core "sort" function). However, instead of using $a and $b, you will need to use $_[0] and $_[1] instead. The returned list is provided as a Collection::Array object.

    This method accepts a single argument.

reverse
    Returns the elements of the array in reversed order. The returned list is provided as a Collection::Array object.

    This method does not accept any arguments.

shuffle
    Returns the elements of the array in random order, like "shuffle" from List::Util. The returned list is provided as a Collection::Array object.

    This method does not accept any arguments.

uniq
    Returns the array with all duplicate elements removed, like "uniq" from List::MoreUtils. The returned list is provided as a Collection::Array object.

    This method does not accept any arguments.

head($count)
    Returns the first $count elements of the array. If $count is greater than the number of elements in the array, the array (without spurious "undef"s) is returned. Negative $count means "all but the last $count elements". The returned list is provided as a Collection::Array object.

tail($count)
    Returns the last $count elements of the array. If $count is greater than the number of elements in the array, the array (without spurious "undef"s) is returned. Negative $count means "all but the first $count elements". The returned list is provided as a Collection::Array object.

join($str)
    Joins every element of the array using the separator given as argument, just like Perl's core "join" function.

      my $joined = $stuff->join(':');
      print "$joined\n";    # prints "foo:bar:baz:boo"

    This method requires a single argument.

print($handle, $str)
    Prints the output of join($str) to $handle. $handle defaults to STDOUT, and join $str defaults to join()'s default of ','.

      $joined = $stuff->print(*STDERR, ';'); # prints foo;bar;baz to STDERR

set($index, $value)
    Given an index and a value, sets the specified array element's value.

    This method returns the value at $index after the set.

    This method requires two arguments.

delete($index)
    Removes the element at the given index from the array.

    This method returns the deleted value, either as an array or scalar as dependent on splice context semantics. Note that if no value exists, it will

    return "undef".

    This method requires one argument.

insert($index, $value)
    Inserts a new element into the array at the given index.

    This method returns the new value at $index, either as an array or scalar as dependent on splice context semantics.

    This method requires two arguments.

clear
    Empties the entire array, like "@array = ()".

    This method does not define a return value.

    This method does not accept any arguments.

accessor($index)
accessor($index, $value)
    This method provides a get/set accessor for the array, based on array indexes. If passed one argument, it returns the value at the specified index. If passed two arguments, it sets the value of the specified index.

    When called as a setter, this method returns the new value at $index.

    This method accepts one or two arguments.

natatime($n)
natatime($n, $code)
    This method returns an iterator which, on each call, returns $n more items from the array, in order, like "natatime" from List::MoreUtils. A coderef can optionally be provided; it will be called on each group of $n elements in the array.

    This method accepts one or two arguments.

shallow_clone
    This method returns a shallow clone of the array reference. The return value is a reference to a new array with the same elements. It is shallow because any elements that were references in the original will be the same references in the clone.

flatten
    This method returns a list of elements in the array. This method is an alias to the elements method.

flatten_deep($level)
    This method returns a flattened list of elements in the array. Will flatten arrays contained within the root array recursively - depth is controlled by the optional $level parameter.

SEE ALSO

•   Data::Perl

•   MooX::HandlesVia

AUTHOR
Matthew Phillips <mattp@cpan.org>

COPYRIGHT AND LICENSE
This software is copyright (c) 2020 by Matthew Phillips <mattp@cpan.org>.

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