MDK::Common::DataStructure(3)

NAME
MDK::Common::DataStructure - miscellaneous list/hash manipulation functions

SYNOPSIS
    use MDK::Common::DataStructure qw(:all);

EXPORTS

sort_numbers(LIST)
    numerical sort (small numbers at beginning)

ikeys(HASH)
    aka sorted integer keys, as simple as "sort { $a <=> $b } keys"

add2hash(HASH REF, HASH REF)
    adds to the first hash the second hash if the key/value is not already there

add2hash_
    adds to the first hash the second hash if the key is not already there

put_in_hash
    adds to the first hash the second hash, crushing existing key/values

member(SCALAR, LIST)
    is the value in the list?

invbool(SCALAR REF)
    toggles the boolean value

listlength(LIST)
    returns the length of the list. Useful in list (opposed to array) context:

        sub f { "a", "b" }
        my $l = listlength f();

    whereas "scalar f()" would return "b"

deref(REF)
    de-reference

deref_array(REF)
    de-reference arrays:

        deref_array [ "a", "b" ]    #=> ("a", "b")
        deref_array "a"             #=> "a"

is_empty_array_ref(SCALAR)
    is the scalar undefined or is the array empty

is_empty_hash_ref(SCALAR)
    is the scalar undefined or is the hash empty

uniq(LIST)
    returns the list with no duplicates (keeping the first elements)

uniq_ { CODE } LIST
    returns the list with no duplicates according to the scalar results of CODE on each element of LIST (keeping the first elements)

        uniq_ { $_->[1] } [ 1, "fo" ], [ 2, "fob" ], [ 3, "fo" ], [ 4, "bar" ]

    gives [ 1, "fo" ], [ 2, "fob" ], [ 4, "bar" ]

difference2(ARRAY REF, ARRAY REF)
    returns the first list without the element of the second list

intersection(ARRAY REF, ARRAY REF, ...)
    returns the elements which are in all lists

next_val_in_array(SCALAR, ARRAY REF)
    finds the value that follow the scalar in the list (circular): "next_val_in_array(3, [1, 2, 3])" gives 1 (do not use a list with duplicates)

group_by2(LIST)
    interprets the list as an ordered hash, returns a list of [key,value]: "group_by2(1 =" 2, 3 => 4, 5 => 6)> gives "[1,2], [3,4], [5,6]"

list2kv(LIST)
    interprets the list as an ordered hash, returns the keys and the values: "list2kv(1 =" 2, 3 => 4, 5 => 6)> gives "[1,3,5], [2,4,6]"

SEE ALSO
MDK::Common