NAME

Data::Perl::Role::Collection::Hash - Wrapping class for Perl's built in hash structure.

VERSION

version 0.002011

SYNOPSIS

  use Data::Perl qw/hash/;
  my $hash = hash(a => 1, b => 2);
  $hash->values; # (1, 2)
  $hash->set('foo', 'bar'); # (a => 1, b => 2, foo => 'bar')

DESCRIPTION

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

PROVIDED METHODS

new($key, $value, ...)

Given an optional list of keys/values, constructs a new Data::Perl::Collection::Hash object initalized with keys/values and returns it.

get($key, $key2, $key3...)

Returns a list of values in the hash for the given keys.

This method requires at least one argument.

set($key => $value, $key2 => $value2...)

Sets the elements in the hash to the given values. It returns the new values set for each key, in the same order as the keys passed to the method.

This method requires at least two arguments, and expects an even number of arguments.

delete($key, $key2, $key3...)

Removes the elements with the given keys.

Returns a list of values in the hash for the deleted keys.

keys

Returns the list of keys in the hash.

This method does not accept any arguments.

exists($key)

Returns true if the given key is present in the hash.

This method requires a single argument.

defined($key)

Returns true if the value of a given key is defined.

This method requires a single argument.

values

Returns the list of values in the hash.

This method does not accept any arguments.

kv

Returns the key/value pairs in the hash as an array of array references.

  for my $pair ( $object->option_pairs ) {
      print "$pair->[0] = $pair->[1]\n";
  }

This method does not accept any arguments.

elements/all

Returns the key/value pairs in the hash as a flattened list..

This method does not accept any arguments.

clear

Resets the hash to an empty value, like "%hash = ()".

This method does not accept any arguments.

count

Returns the number of elements in the hash. Also useful for not empty: "has_options => 'count'".

This method does not accept any arguments.

is_empty

If the hash is populated, returns false. Otherwise, returns true.

This method does not accept any arguments.

accessor($key)

accessor($key, $value)

If passed one argument, returns the value of the specified key. If passed two arguments, sets the value of the specified key.

When called as a setter, this method returns the value that was set.

shallow_clone

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

_array_class

The name of the class which returned lists are instances of; i.e. "Data::Perl::Collection::Array".

Subclasses of this class can override this method.

Note that "each" is deliberately omitted, due to its stateful interaction with the hash iterator. "keys" or "kv" are much safer.

AUTHOR

Matthew Phillips <mattp@cpan.org>

COPYRIGHT AND LICENSE

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