NAME

Data::Combination - Hash and Array element combination generator

SYNOPIS

    use Data::Combination;
    
    #Generate combination of array with two 'fields'
    my $result=Data::Combination::combinations([[1,2,3], [qw(a b c)])
    
    # $result is an array ref of all combinations of the two fields
    [
            [1,a],
            [1,b],
            [1,c],

            [2,a],
            [2,b],
            [2,c],

            [3,a],
            [3,b],
            [3,c]
    ]

    #Generate combination of hash with two 'fields'
    my $result=Data::Combination::combinations(key1=>[1,2,3], key2=>[qw(a b c)])

    # $result is an array ref of all combinations of the two fields
    [
            {key1=>1,key2=>a},
            {key1=>2,key2=>a},
            {key1=>3,key2=>a},
            
            {key1=>1,key2=>b},
            {key1=>2,key2=>b},
            {key1=>3,key2=>b},

            {key1=>1,key2=>c},
            {key1=>2,key2=>c},
            {key1=>3,key2=>c},
    ]

DESCRIPTION

Data::Combinations generates hashes or arrays by making combinations of values for keys with array values.

EXAMPLES

Array examples:

    ===
    input:
    ["a","b","c"]

    output:
    [
            ["a","b","c"]
    ]
    
    ===
    input:
    [["a","b","c"]]

    output:
    [
            ["a"],
            ["b"],
            ["c"]
    ]

    ===
    input:
    [["a","b"], [1,2]];

    output:
    [
            [a, 1],
            [a, 2],
            [b, 1],
            [b, 2]
    ]

    ===
    input:
    ["a", "b", ["x","y"], {key=>"val"}]

    output:
    [
            ["a","b","x", {key=>"val"}],
            ["a","b","y", {key=>"val"}]
    ]

Hash examples:

    ===
    input:
    {k1=>"a",k2=>"b",k3=>"c"}

    outputs:
    [
            {k1=>"a",k2=>"b",k3=>"c"}
    ]
    
    ===
    input:
    {k1=>["a","b","c"]}

    output:
    [
            {k1=>"a"},
            {k2=>"b"},
            {k3=>"c"}
    ]

    ===
    input:
    {k1=>["a","b"], k2=>[1,2]}

    output:
    [
            {k1=>"a", k2=>1},
            {k1=>"b", k2=>2},
            {k1=>"a", k2=>1},
            {k1=>"b", k2=>2}
    ]

    ===
    input:
    [
            {k1=>"a", k2=>"b", k3=>["x","y"], k4=>{key=>"val"}}
    ]

    output:
    [
            {k1=>"a",k2=>"b",k3=>"x", k4=>{key=>"val"}},
            {k1=>"a",k2=>"b",k3=>"y", k4=>{key=>"val"}}
    ]

API

The module currently has a single function, which isn't exported. To use it it must be addressed by its full name

combinations

    my $result=Data::Combinations::combinations $ref;

Generates the combinations of 'fields' in $ref. A 'field' is either a hash element or array element which contains a reference to an array. If a field contains another scalar type, it is wrapped into an array of a single element.

If $ref is a hash, the keys are preserved in the outputs, with the values for each key used for combination.

If $ref is an array, the indexes are preserved in the outputs, with the values for each index used for combination.

Return value is a reference to an array of the created combinations.

SEE ALSO

There are other permutation modules. But they only work with flat lists?

Algorithm::Permute

Math::Permute::Lists

Math::Combinatorics

AUTHOR

Ruben Westerberg, drclaw@mac.com

REPOSITORTY and BUGS

Please report any bugs via git hub: http://github.com/drclaw1394/perl-data-combination

COPYRIGHT AND LICENSE

Copyright (C) 2022 by Ruben Westerberg

This library is free software; you can redistribute it and/or modify it under the same terms as Perl or the MIT license.

DISCLAIMER OF WARRANTIES

THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.