Hash::MoreUtils - Provide the stuff missing in Hash::Util
use Hash::MoreUtils qw(:all);
my %h = (foo => "bar", FOO => "BAR", true => 1, false => 0);
my %s = slice \%h, qw(true false); # (true => 1, false => 0)
my %f = slice_false \%h; # (false => 0)
my %u = slice_grep { $_ =~ m/^[A-Z]/ }, \%h; # (FOO => "BAR")
my %r = safe_reverse \%h; # (bar => "foo", BAR => "FOO", 0 => "false", 1 => "true")
Similar to List::MoreUtils, Hash::MoreUtils contains trivial
but commonly-used functionality for hashes. The primary focus for
the moment is providing a common API - speeding up by XS is far
away at the moment.
Returns a hash containing the (key, value) pair for every key in LIST.
If no LIST is given, all keys are assumed as LIST.
As slice, but only includes keys whose values are
defined.
If no LIST is given, all keys are assumed as LIST.
As slice but only includes keys which exist in the
hashref.
If no LIST is given, all keys are assumed as LIST.
As slice but without any (key/value) pair whose key is
in LIST.
If no LIST is given, in opposite to slice an empty list
is assumed, thus nothing will be deleted.
Returns a HASH containing the (key => undef) pair for every
LIST element (as key) that does not exist hashref.
If no LIST is given there are obviously no non-existent
keys in HASHREF so the returned HASH is empty.
Searches for undefined slices with the given LIST
elements as keys in the given HASHREF.
Returns a HASHREF containing the slices (key -> undef)
for every undefined item.
To search for undefined slices slice_notdef needs a
LIST with items to search for (as keys). If no LIST
is given it returns an empty HASHREF even when the given
HASHREF contains undefined slices.
A special slice_grep which returns only those elements
of the hash which's values evaluates to TRUE.
If no LIST is given, all keys are assumed as LIST.
A special slice_grep which returns only those elements
of the hash which's values evaluates to FALSE.
If no LIST is given, all keys are assumed as LIST.
As slice, with an arbitrary condition.
If no LIST is given, all keys are assumed as LIST.
Unlike grep, the condition is not given aliases to
elements of anything. Instead, %_ is set to the
contents of the hashref, to avoid accidentally
auto-vivifying when checking keys or values. Also,
'uninitialized' warnings are turned off in the enclosing
scope.
Returns a hash containing the (key, value) pair for every
key in MAP.
If no MAP is given, all keys of HASHREF are assumed mapped to themselves.
As slice_map, but only includes keys whose values are
defined.
If no MAP is given, all keys of HASHREF are assumed mapped to themselves.
As slice_map but only includes keys which exist in the
hashref.
If no MAP is given, all keys of HASHREF are assumed mapped to themselves.
As slice_missing but checks for missing keys (of MAP) and map to the value (of MAP) as key in the returned HASH.
The slices of the returned HASHREF are always undefined.
If no MAP is given, slice_missing will be used on HASHREF which will return an empty HASH.
As slice_notdef but checks for undefined keys (of MAP) and map to the value (of MAP) as key in the returned HASH.
If no MAP is given, slice_notdef will be used on HASHREF which will return an empty HASH.
As slice_map, but only includes pairs whose values are
TRUE.
If no MAP is given, all keys of HASHREF are assumed mapped to themselves.
As slice_map, but only includes pairs whose values are
FALSE.
If no MAP is given, all keys of HASHREF are assumed mapped to themselves.
As slice_map, with an arbitrary condition.
If no MAP is given, all keys of HASHREF are assumed mapped to themselves.
Unlike grep, the condition is not given aliases to
elements of anything. Instead, %_ is set to the
contents of the hashref, to avoid accidentally
auto-vivifying when checking keys or values. Also,
'uninitialized' warnings are turned off in the enclosing
scope.
my @array_of_pairs = hashsort \%hash;
my @pairs_by_length = hashsort sub { length($a) <=> length($b) }, \%hash;
Returns the (key, value) pairs of the hash, sorted by some
property of the keys. By default (if no sort block given), sorts the
keys with cmp.
I'm not convinced this is useful yet. If you can think of some way it could be more so, please let me know.
my %dup_rev = safe_reverse \%hash
sub croak_dup {
my ($k, $v, $r) = @_;
exists( $r->{$v} ) and
croak "Cannot safe reverse: $v would be mapped to both $k and $r->{$v}";
$v;
};
my %easy_rev = safe_reverse \&croak_dup, \%hash
Returns safely reversed hash (value, key pairs of original hash). If no
BLOCK is given, following routine will be used:
sub merge_dup {
my ($k, $v, $r) = @_;
return exists( $r->{$v} )
? ( ref($r->{$v}) ? [ @{$r->{$v}}, $k ] : [ $r->{$v}, $k ] )
: $k;
};
The BLOCK will be called with 3 arguments:
-
keyThe key from the
( key, value )pair in the original hash -
valueThe value from the
( key, value )pair in the original hash -
ref-hashReference to the reversed hash (read-only)
The BLOCK is expected to return the value which will used
for the resulting hash.
Hans Dieter Pearcey, <hdp@cpan.org>,
Jens Rehsack, <rehsack@cpan.org>
Please report any bugs or feature requests to
bug-hash-moreutils@rt.cpan.org, or through the web interface at
http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Hash-MoreUtils.
I will be notified, and then you'll automatically be notified of progress on
your bug as I make changes.
You can find documentation for this module with the perldoc command.
perldoc Hash::MoreUtils
You can also look for information at:
-
RT: CPAN's request tracker
-
AnnoCPAN: Annotated CPAN documentation
-
CPAN Ratings
-
Search CPAN
Copyright 2005 Hans Dieter Pearcey, all rights reserved. Copyright 2010-2018 Jens Rehsack
This program is free software; you can redistribute it and/or modify it under the terms of either: the GNU General Public License as published by the Free Software Foundation; or the Artistic License.
See http://dev.perl.org/licenses/ for more information.