NAME
    List::AllUtils - Combines List::Util and List::MoreUtils in one
    bite-sized package

VERSION
    version 0.08

SYNOPSIS
        use List::AllUtils qw( first any );

        # _Everything_ from List::Util and List::MoreUtils
        use List::AllUtils qw( :all );

        my @numbers = ( 1, 2, 3, 5, 7 );
        # or don't import anything
        return List::AllUtils::first { $_ > 5 } @numbers;

DESCRIPTION
    Are you sick of trying to remember whether a particular helper is
    defined in "List::Util" or "List::MoreUtils"? I sure am. Now you don't
    have to remember. This module will export all of the functions that
    either of those two modules defines.

    Note that all function documentation has been shamelessly copied from
    List::Util and <List::MoreUtils>.

LIST-REDUCTION FUNCTIONS
    The following set of functions all reduce a list down to a single value.

  reduce BLOCK LIST
    Reduces LIST by calling BLOCK, in a scalar context, multiple times,
    setting $a and $b each time. The first call will be with $a and $b set
    to the first two elements of the list, subsequent calls will be done by
    setting $a to the result of the previous call and $b to the next element
    in the list.

    Returns the result of the last call to BLOCK. If LIST is empty then
    "undef" is returned. If LIST only contains one element then that element
    is returned and BLOCK is not executed.

        $foo = reduce { $a < $b ? $a : $b } 1..10       # min
        $foo = reduce { $a lt $b ? $a : $b } 'aa'..'zz' # minstr
        $foo = reduce { $a + $b } 1 .. 10               # sum
        $foo = reduce { $a . $b } @bar                  # concat

    If your algorithm requires that "reduce" produce an identity value, then
    make sure that you always pass that identity value as the first argument
    to prevent "undef" being returned

      $foo = reduce { $a + $b } 0, @values;             # sum with 0 identity value

    The remaining list-reduction functions are all specialisations of this
    generic idea.

  first BLOCK LIST
    Similar to "grep" in that it evaluates BLOCK setting $_ to each element
    of LIST in turn. "first" returns the first element where the result from
    BLOCK is a true value. If BLOCK never returns true or LIST was empty
    then "undef" is returned.

        $foo = first { defined($_) } @list    # first defined value in @list
        $foo = first { $_ > $value } @list    # first value in @list which
                                              # is greater than $value

    This function could be implemented using "reduce" like this

        $foo = reduce { defined($a) ? $a : wanted($b) ? $b : undef } undef, @list

    for example wanted() could be defined() which would return the first
    defined value in @list

  max LIST
    Returns the entry in the list with the highest numerical value. If the
    list is empty then "undef" is returned.

        $foo = max 1..10                # 10
        $foo = max 3,9,12               # 12
        $foo = max @bar, @baz           # whatever

    This function could be implemented using "reduce" like this

        $foo = reduce { $a > $b ? $a : $b } 1..10

  maxstr LIST
    Similar to "max", but treats all the entries in the list as strings and
    returns the highest string as defined by the "gt" operator. If the list
    is empty then "undef" is returned.

        $foo = maxstr 'A'..'Z'          # 'Z'
        $foo = maxstr "hello","world"   # "world"
        $foo = maxstr @bar, @baz        # whatever

    This function could be implemented using "reduce" like this

        $foo = reduce { $a gt $b ? $a : $b } 'A'..'Z'

  min LIST
    Similar to "max" but returns the entry in the list with the lowest
    numerical value. If the list is empty then "undef" is returned.

        $foo = min 1..10                # 1
        $foo = min 3,9,12               # 3
        $foo = min @bar, @baz           # whatever

    This function could be implemented using "reduce" like this

        $foo = reduce { $a < $b ? $a : $b } 1..10

  minstr LIST
    Similar to "min", but treats all the entries in the list as strings and
    returns the lowest string as defined by the "lt" operator. If the list
    is empty then "undef" is returned.

        $foo = minstr 'A'..'Z'          # 'A'
        $foo = minstr "hello","world"   # "hello"
        $foo = minstr @bar, @baz        # whatever

    This function could be implemented using "reduce" like this

        $foo = reduce { $a lt $b ? $a : $b } 'A'..'Z'

  sum LIST
    Returns the sum of all the elements in LIST. If LIST is empty then
    "undef" is returned.

        $foo = sum 1..10                # 55
        $foo = sum 3,9,12               # 24
        $foo = sum @bar, @baz           # whatever

    This function could be implemented using "reduce" like this

        $foo = reduce { $a + $b } 1..10

  sum0 LIST
    Similar to "sum", except this returns 0 when given an empty list, rather
    than "undef".

KEY/VALUE PAIR LIST FUNCTIONS
    The following set of functions, all inspired by List::Pairwise, consume
    an even-sized list of pairs. The pairs may be key/value associations
    from a hash, or just a list of values. The functions will all preserve
    the original ordering of the pairs, and will not be confused by multiple
    pairs having the same "key" value - nor even do they require that the
    first of each pair be a plain string.

  pairgrep BLOCK KVLIST
    Similar to perl's "grep" keyword, but interprets the given list as an
    even-sized list of pairs. It invokes the BLOCK multiple times, in scalar
    context, with $a and $b set to successive pairs of values from the
    KVLIST.

    Returns an even-sized list of those pairs for which the BLOCK returned
    true in list context, or the count of the number of pairs in scalar
    context. (Note, therefore, in scalar context that it returns a number
    half the size of the count of items it would have returned in list
    context).

        @subset = pairgrep { $a =~ m/^[[:upper:]]+$/ } @kvlist

    Similar to "grep", "pairgrep" aliases $a and $b to elements of the given
    list. Any modifications of it by the code block will be visible to the
    caller.

  pairfirst BLOCK KVLIST
    Similar to the "first" function, but interprets the given list as an
    even-sized list of pairs. It invokes the BLOCK multiple times, in scalar
    context, with $a and $b set to successive pairs of values from the
    KVLIST.

    Returns the first pair of values from the list for which the BLOCK
    returned true in list context, or an empty list of no such pair was
    found. In scalar context it returns a simple boolean value, rather than
    either the key or the value found.

        ( $key, $value ) = pairfirst { $a =~ m/^[[:upper:]]+$/ } @kvlist

    Similar to "grep", "pairfirst" aliases $a and $b to elements of the
    given list. Any modifications of it by the code block will be visible to
    the caller.

  pairmap BLOCK KVLIST
    Similar to perl's "map" keyword, but interprets the given list as an
    even-sized list of pairs. It invokes the BLOCK multiple times, in list
    context, with $a and $b set to successive pairs of values from the
    KVLIST.

    Returns the concatenation of all the values returned by the BLOCK in
    list context, or the count of the number of items that would have been
    returned in scalar context.

        @result = pairmap { "The key $a has value $b" } @kvlist

    Similar to "map", "pairmap" aliases $a and $b to elements of the given
    list. Any modifications of it by the code block will be visible to the
    caller.

  pairs KVLIST
    A convenient shortcut to operating on even-sized lists of pairs, this
    function returns a list of ARRAY references, each containing two items
    from the given list. It is a more efficient version of

        pairmap { [ $a, $b ] } KVLIST

    It is most convenient to use in a "foreach" loop, for example:

        foreach ( pairs @KVLIST ) {
           my ( $key, $value ) = @$_;
           ...
        }

  pairkeys KVLIST
    A convenient shortcut to operating on even-sized lists of pairs, this
    function returns a list of the the first values of each of the pairs in
    the given list. It is a more efficient version of

        pairmap { $a } KVLIST

  pairvalues KVLIST
    A convenient shortcut to operating on even-sized lists of pairs, this
    function returns a list of the the second values of each of the pairs in
    the given list. It is a more efficient version of

        pairmap { $b } KVLIST

OTHER FUNCTIONS
  shuffle LIST
    Returns the elements of LIST in a random order

        @cards = shuffle 0..51      # 0..51 in a random order

List::MoreUtils FUNCTIONS
  any BLOCK LIST
    Returns a true value if any item in LIST meets the criterion given
    through BLOCK. Sets $_ for each item in LIST in turn:

        print "At least one value undefined"
            if any { ! defined($_) } @list;

    Returns false otherwise, or if LIST is empty.

  all BLOCK LIST
    Returns a true value if all items in LIST meet the criterion given
    through BLOCK, or if LIST is empty. Sets $_ for each item in LIST in
    turn:

        print "All items defined"
            if all { defined($_) } @list;

    Returns false otherwise.

  none BLOCK LIST
    Logically the negation of "any". Returns a true value if no item in LIST
    meets the criterion given through BLOCK, or if LIST is empty. Sets $_
    for each item in LIST in turn:

        print "No value defined"
            if none { defined($_) } @list;

    Returns false otherwise.

  notall BLOCK LIST
    Logically the negation of "all". Returns a true value if not all items
    in LIST meet the criterion given through BLOCK. Sets $_ for each item in
    LIST in turn:

        print "Not all values defined"
            if notall { defined($_) } @list;

    Returns false otherwise, or if LIST is empty.

  true BLOCK LIST
    Counts the number of elements in LIST for which the criterion in BLOCK
    is true. Sets $_ for each item in LIST in turn:

        printf "%i item(s) are defined", true { defined($_) } @list;

  false BLOCK LIST
    Counts the number of elements in LIST for which the criterion in BLOCK
    is false. Sets $_ for each item in LIST in turn:

        printf "%i item(s) are not defined", false { defined($_) } @list;

  firstidx BLOCK LIST
  first_index BLOCK LIST
    Returns the index of the first element in LIST for which the criterion
    in BLOCK is true. Sets $_ for each item in LIST in turn:

        my @list = (1, 4, 3, 2, 4, 6);
        printf "item with index %i in list is 4", firstidx { $_ == 4 } @list;
        __END__
        item with index 1 in list is 4

    Returns -1 if no such item could be found.

    "first_index" is an alias for "firstidx".

  lastidx BLOCK LIST
  last_index BLOCK LIST
    Returns the index of the last element in LIST for which the criterion in
    BLOCK is true. Sets $_ for each item in LIST in turn:

        my @list = (1, 4, 3, 2, 4, 6);
        printf "item with index %i in list is 4", lastidx { $_ == 4 } @list;
        __END__
        item with index 4 in list is 4

    Returns -1 if no such item could be found.

    "last_index" is an alias for "lastidx".

  insert_after BLOCK VALUE LIST
    Inserts VALUE after the first item in LIST for which the criterion in
    BLOCK is true. Sets $_ for each item in LIST in turn.

        my @list = qw/This is a list/;
        insert_after { $_ eq "a" } "longer" => @list;
        print "@list";
        __END__
        This is a longer list

  insert_after_string STRING VALUE LIST
    Inserts VALUE after the first item in LIST which is equal to STRING.

        my @list = qw/This is a list/;
        insert_after_string "a", "longer" => @list;
        print "@list";
        __END__
        This is a longer list

  apply BLOCK LIST
    Applies BLOCK to each item in LIST and returns a list of the values
    after BLOCK has been applied. In scalar context, the last element is
    returned. This function is similar to "map" but will not modify the
    elements of the input list:

        my @list = (1 .. 4);
        my @mult = apply { $_ *= 2 } @list;
        print "\@list = @list\n";
        print "\@mult = @mult\n";
        __END__
        @list = 1 2 3 4
        @mult = 2 4 6 8

    Think of it as syntactic sugar for

        for (my @mult = @list) { $_ *= 2 }

  before BLOCK LIST
    Returns a list of values of LIST up to (and not including) the point
    where BLOCK returns a true value. Sets $_ for each element in LIST in
    turn.

  before_incl BLOCK LIST
    Same as "before" but also includes the element for which BLOCK is true.

  after BLOCK LIST
    Returns a list of the values of LIST after (and not including) the point
    where BLOCK returns a true value. Sets $_ for each element in LIST in
    turn.

        @x = after { $_ % 5 == 0 } (1..9);    # returns 6, 7, 8, 9

  after_incl BLOCK LIST
    Same as "after" but also includes the element for which BLOCK is true.

  indexes BLOCK LIST
    Evaluates BLOCK for each element in LIST (assigned to $_) and returns a
    list of the indices of those elements for which BLOCK returned a true
    value. This is just like "grep" only that it returns indices instead of
    values:

        @x = indexes { $_ % 2 == 0 } (1..10);   # returns 1, 3, 5, 7, 9

  firstval BLOCK LIST
  first_value BLOCK LIST
    Returns the first element in LIST for which BLOCK evaluates to true.
    Each element of LIST is set to $_ in turn. Returns "undef" if no such
    element has been found.

    "first_val" is an alias for "firstval".

  lastval BLOCK LIST
  last_value BLOCK LIST
    Returns the last value in LIST for which BLOCK evaluates to true. Each
    element of LIST is set to $_ in turn. Returns "undef" if no such element
    has been found.

    "last_val" is an alias for "lastval".

  pairwise BLOCK ARRAY1 ARRAY2
    Evaluates BLOCK for each pair of elements in ARRAY1 and ARRAY2 and
    returns a new list consisting of BLOCK's return values. The two elements
    are set to $a and $b. Note that those two are aliases to the original
    value so changing them will modify the input arrays.

        @a = (1 .. 5);
        @b = (11 .. 15);
        @x = pairwise { $a + $b } @a, @b;   # returns 12, 14, 16, 18, 20

        # mesh with pairwise
        @a = qw/a b c/;
        @b = qw/1 2 3/;
        @x = pairwise { ($a, $b) } @a, @b;  # returns a, 1, b, 2, c, 3

  each_array ARRAY1 ARRAY2 ...
    Creates an array iterator to return the elements of the list of arrays
    ARRAY1, ARRAY2 throughout ARRAYn in turn. That is, the first time it is
    called, it returns the first element of each array. The next time, it
    returns the second elements. And so on, until all elements are
    exhausted.

    This is useful for looping over more than one array at once:

        my $ea = each_array(@a, @b, @c);
        while ( my ($a, $b, $c) = $ea->() )   { .... }

    The iterator returns the empty list when it reached the end of all
    arrays.

    If the iterator is passed an argument of '"index"', then it returns the
    index of the last fetched set of values, as a scalar.

  each_arrayref LIST
    Like each_array, but the arguments are references to arrays, not the
    plain arrays.

  natatime EXPR, LIST
    Creates an array iterator, for looping over an array in chunks of $n
    items at a time. (n at a time, get it?). An example is probably a better
    explanation than I could give in words.

    Example:

        my @x = ('a' .. 'g');
        my $it = natatime 3, @x;
        while (my @vals = $it->())
        {
            print "@vals\n";
        }

    This prints

        a b c
        d e f
        g

  mesh ARRAY1 ARRAY2 [ ARRAY3 ... ]
  zip ARRAY1 ARRAY2 [ ARRAY3 ... ]
    Returns a list consisting of the first elements of each array, then the
    second, then the third, etc, until all arrays are exhausted.

    Examples:

        @x = qw/a b c d/;
        @y = qw/1 2 3 4/;
        @z = mesh @x, @y;       # returns a, 1, b, 2, c, 3, d, 4

        @a = ('x');
        @b = ('1', '2');
        @c = qw/zip zap zot/;
        @d = mesh @a, @b, @c;   # x, 1, zip, undef, 2, zap, undef, undef, zot

    "zip" is an alias for "mesh".

  uniq LIST
  distinct LIST
    Returns a new list by stripping duplicate values in LIST. The order of
    elements in the returned list is the same as in LIST. In scalar context,
    returns the number of unique elements in LIST.

        my @x = uniq 1, 1, 2, 2, 3, 5, 3, 4; # returns 1 2 3 5 4
        my $x = uniq 1, 1, 2, 2, 3, 5, 3, 4; # returns 5

  minmax LIST
    Calculates the minimum and maximum of LIST and returns a two element
    list with the first element being the minimum and the second the
    maximum. Returns the empty list if LIST was empty.

    The "minmax" algorithm differs from a naive iteration over the list
    where each element is compared to two values being the so far calculated
    min and max value in that it only requires 3n/2 - 2 comparisons. Thus it
    is the most efficient possible algorithm.

    However, the Perl implementation of it has some overhead simply due to
    the fact that there are more lines of Perl code involved. Therefore,
    LIST needs to be fairly big in order for "minmax" to win over a naive
    implementation. This limitation does not apply to the XS version.

  part BLOCK LIST
    Partitions LIST based on the return value of BLOCK which denotes into
    which partition the current value is put.

    Returns a list of the partitions thusly created. Each partition created
    is a reference to an array.

        my $i = 0;
        my @part = part { $i++ % 2 } 1 .. 8;   # returns [1, 3, 5, 7], [2, 4, 6, 8]

    You can have a sparse list of partitions as well where non-set
    partitions will be undef:

        my @part = part { 2 } 1 .. 10;          # returns undef, undef, [ 1 .. 10 ]

    Be careful with negative values, though:

        my @part = part { -1 } 1 .. 10;
        __END__
        Modification of non-creatable array value attempted, subscript -1 ...

    Negative values are only okay when they refer to a partition previously
    created:

        my @idx  = ( 0, 1, -1 );
        my $i    = 0;
        my @part = part { $idx[$++ % 3] } 1 .. 8; # [1, 4, 7], [2, 3, 5, 6, 8]

EXPORTS
    This module exports nothing by default. You can import functions by
    name, or get everything with the ":all" tag.

SEE ALSO
    "List::Util" and "List::MoreUtils", obviously.

    Also see "Util::Any", which unifies many more util modules, and also
    lets you rename functions as part of the import.

BUGS
    Please report any bugs or feature requests to
    "bug-list-allutils@rt.cpan.org", or through the web interface at
    <http://rt.cpan.org>. I will be notified, and then you'll automatically
    be notified of progress on your bug as I make changes.

AUTHOR
    Dave Rolsky <autarch@urth.org>

COPYRIGHT AND LICENSE
    This software is Copyright (c) 2014 by Dave Rolsky.

    This is free software, licensed under:

      The Artistic License 2.0 (GPL Compatible)

