MDK::Common::DataStructure

Section: User Contributed Perl Documentation (3)
Updated: 2014-01-24
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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


 

Index

NAME
SYNOPSIS
EXPORTS
SEE ALSO