1Hash::Merge::Simple(3)User Contributed Perl DocumentationHash::Merge::Simple(3)
2
3
4

NAME

6       Hash::Merge::Simple - Recursively merge two or more hashes, simply
7

VERSION

9       version 0.051
10

SYNOPSIS

12           use Hash::Merge::Simple qw/ merge /;
13
14           my $a = { a => 1 };
15           my $b = { a => 100, b => 2};
16
17           # Merge with righthand hash taking precedence
18           my $c = merge $a, $b;
19           # $c is { a => 100, b => 2 } ... Note: a => 100 has overridden => 1
20
21           # Also, merge will take care to recursively merge any subordinate hashes found
22           my $a = { a => 1, c => 3, d => { i => 2 }, r => {} };
23           my $b = { b => 2, a => 100, d => { l => 4 } };
24           my $c = merge $a, $b;
25           # $c is { a => 100, b => 2, c => 3, d => { i => 2, l => 4 }, r => {} }
26
27           # You can also merge more than two hashes at the same time
28           # The precedence increases from left to right (the rightmost has the most precedence)
29           my $everything = merge $this, $that, $mine, $yours, $kitchen_sink, ...;
30

DESCRIPTION

32       Hash::Merge::Simple will recursively merge two or more hashes and
33       return the result as a new hash reference. The merge function will
34       descend and merge hashes that exist under the same node in both the
35       left and right hash, but doesn't attempt to combine arrays, objects,
36       scalars, or anything else. The rightmost hash also takes precedence,
37       replacing whatever was in the left hash if a conflict occurs.
38
39       This code was pretty much taken straight from Catalyst::Utils, and
40       modified to handle more than 2 hashes at the same time.
41

USAGE

43   Hash::Merge::Simple->merge( <hash1>, <hash2>, <hash3>, ..., <hashN> )
44   Hash::Merge::Simple::merge( <hash1>, <hash2>, <hash3>, ..., <hashN> )
45       Merge <hash1> through <hashN>, with the nth-most (rightmost) hash
46       taking precedence.
47
48       Returns a new hash reference representing the merge.
49
50       NOTE: The code does not currently check for cycles, so infinite loops
51       are possible:
52
53           my $a = {};
54           $a->{b} = $a;
55           merge $a, $a;
56
57       NOTE: If you want to avoid giving/receiving side effects with the
58       merged result, use "clone_merge" or "dclone_merge" An example of this
59       problem (thanks Uri):
60
61           my $left = { a => { b => 2 } } ;
62           my $right = { c => 4 } ;
63
64           my $result = merge( $left, $right ) ;
65
66           $left->{a}{b} = 3 ;
67           $left->{a}{d} = 5 ;
68
69           # $result->{a}{b} == 3 !
70           # $result->{a}{d} == 5 !
71
72   Hash::Merge::Simple->clone_merge( <hash1>, <hash2>, <hash3>, ..., <hashN> )
73   Hash::Merge::Simple::clone_merge( <hash1>, <hash2>, <hash3>, ..., <hashN> )
74       Perform a merge, clone the merge, and return the result
75
76       This is useful in cases where you need to ensure that the result can be
77       tweaked without fear of giving/receiving any side effects
78
79       This method will use Clone to do the cloning
80
81   Hash::Merge::Simple->dclone_merge( <hash1>, <hash2>, <hash3>, ..., <hashN>
82       )
83   Hash::Merge::Simple::dclone_merge( <hash1>, <hash2>, <hash3>, ..., <hashN>
84       )
85       Perform a merge, clone the merge, and return the result
86
87       This is useful in cases where you need to ensure that the result can be
88       tweaked without fear of giving/receiving any side effects
89
90       This method will use Storable (dclone) to do the cloning
91

SEE ALSO

93       Hash::Merge
94
95       Catalyst::Utils
96
97       Clone
98
99       Storable
100

ACKNOWLEDGEMENTS

102       This code was pretty much taken directly from Catalyst::Utils:
103
104       Sebastian Riedel "sri@cpan.org"
105
106       Yuval Kogman "nothingmuch@woobling.org"
107

AUTHOR

109       Robert Krimen <robertkrimen@gmail.com>
110

112       This software is copyright (c) 2010 by Robert Krimen.
113
114       This is free software; you can redistribute it and/or modify it under
115       the same terms as the Perl 5 programming language system itself.
116
117
118
119perl v5.34.0                      2022-01-21            Hash::Merge::Simple(3)
Impressum