List::Objects::WithUtils::Role::Array - Array manipulation methods
## Via List::Objects::WithUtils::Array -> use List::Objects::WithUtils 'array'; my $array = array(qw/ a b c /); $array->push(qw/ d e f /); my @upper = $array->map(sub { uc })->all; if ( $array->has_any(sub { $_ eq 'a' }) ) { ... } my $sum = array(1 .. 10)->reduce(sub { $_[0] + $_[1] }); # See below for full list of methods ## As a Role -> use Role::Tiny::With; with 'List::Objects::WithUtils::Role::Array';
A Role::Tiny role defining methods for creating and manipulating ARRAY-type objects.
List::Objects::WithUtils::Array consumes this role (along with List::Objects::WithUtils::Role::WithJunctions) to provide array() object methods.
In addition to the methods documented below, these objects provide a TO_JSON method exporting a plain ARRAY-type reference for convenience when feeding JSON::Tiny or similar.
TO_JSON
Constructs a new ARRAY-type object.
Creates a shallow clone of the current object.
Returns the number of elements in the array.
Returns boolean true if the array is empty.
See "count".
Clears the array entirely.
Splices a given index out of the array.
$array->insert( $position, $value );
Inserts a value at a given position.
Pops the last element off the array and returns it.
Pushes elements to the end of the array.
Returns the array object.
$array->set( $index, $value );
Takes an array element and a new value to set.
Shifts the first element off the beginning of the array and returns it.
Adds elements to the beginning of the array.
# 2-arg splice (remove elements): my $spliced = $array->splice(0, 2) # 3-arg splice (replace): $array->splice(0, 1, 'abc');
Performs a splice() on the current list and returns a new array object consisting of the items returned from the splice.
splice()
The existing array is modified in-place.
use Types::Standard -all; my $valid = array(qw/foo bar baz/)->validated(Str);
Accepts a Type::Tiny type, against which each element of the current array will be checked before being added to the new array.
If the element fails the type check but can be coerced, the coerced value will be added to the new array.
Dies with a stack trace if the value fails type checks and can't be coerced.
See: Types::Standard, List::Objects::Types
Returns all elements in the array as a plain list.
my ($true, $false) = array( 1 .. 10 ) ->bisect(sub { $_[0] >= 5 }) ->all; my @bigger = $true->all; # ( 5 .. 10 ) my @smaller = $false->all; # ( 1 .. 4 )
Like "part", but creates an array-type object containing two partitions; the first contains all items for which the subroutine evaluates to true, the second contains the remaining items.
Same as "all"; included for consistency with hash-type objects.
Flatten array objects to plain lists, possibly recursively.
flatten without arguments is the same as "all":
flatten
my @flat = array( 1, 2, [ 3, 4 ] )->flatten; # @flat = ( 1, 2, [ 3, 4 ] );
If a depth is specified, sub-arrays are recursively flattened until the specified depth is reached:
my @flat = array( 1, 2, [ 3, 4 ] )->flatten(1); # @flat = ( 1, 2, 3, 4 ); my @flat = array( 1, 2, [ 3, 4, [ 5, 6 ] ] )->flatten(1); # @flat = ( 1, 2, 3, 4, [ 5, 6 ] );
This works with both ARRAY-type references and array objects:
my @flat = array( 1, 2, [ 3, 4, array( 5, 6 ) ] )->flatten(2); # @flat = ( 1, 2, 3, 4, 5, 6 );
(Specifically, consumers of this role are flattened; other ARRAY-type objects are left alone.)
See "flatten_all" for flattening to an unlimited depth.
Returns a plain list consisting of all sub-arrays recursively flattened. Also see "flatten".
Returns the array element corresponding to a specified index.
my ($first, $rest) = $array->head;
In list context, returns the first element of the list, and a new array-type object containing the remaining list. The original object's list is untouched.
In scalar context, returns just the first element of the array:
my $first = $array->head;
Similar to "head", but returns either the last element and a new array-type object containing the remaining list (in list context), or just the last element of the list (in scalar context).
my $str = $array->join(' ');
Joins the array's elements and returns the joined string.
Defaults to ',' if no delimiter is specified.
my $meshed = array(qw/ a b c /)->mesh( array( 1 .. 3 ) ); $meshed->all; # 'a', 1, 'b', 2, 'c', 3
Takes array references or objects and returns a new array object consisting of one element from each array, in turn, until all arrays have been traversed fully.
You can mix and match references and objects freely:
my $meshed = array(qw/ a b c /)->mesh( array( 1 .. 3 ), [ qw/ foo bar baz / ], );
my $parts = array( 1 .. 8 )->part(sub { $i++ % 2 }); # Returns array objects: $parts->get(0)->all; # 1, 3, 5, 7 $parts->get(1)->all; # 2, 4, 6, 8
Takes a subroutine that indicates into which partition each value should be placed.
Returns an array-type object containing partitions represented as array-type objects, as seen above.
Skipped partitions are empty array objects:
my $parts = array(qw/ foo bar /)->part(sub { 1 }); $parts->get(0)->is_empty; # true $parts->get(1)->is_empty; # false
The subroutine is passed the value we are operating on:
array(qw/foo bar baz 1 2 3/) ->part(sub { $_[0] =~ /^[0-9]+$/ ? 0 : 1 }) ->get(1) ->all; # 'foo', 'bar', 'baz'
Returns a random element from the array.
Returns a new array object consisting of the reversed list of elements.
my $shuffled = $array->shuffle;
Returns a new array object containing the shuffled list.
my $slice = $array->sliced(1, 3, 5);
Returns a new array object consisting of the elements retrived from the specified indexes.
my $tuples = array(1 .. 7)->tuples(2); # Returns: # array( # [ 1, 2 ], # [ 3, 4 ], # [ 5, 6 ], # [ 7, undef ], # )
Simple sugar for "natatime"; returns a new array object consisting of tuples (unblessed ARRAY references) of the specified size (defaults to 2).
tuples accepts Type::Tiny types as an optional second parameter; if specified, items in tuples are checked against the type and a coercion is attempted if the initial type-check fails; a stack-trace is thrown if a value in a tuple cannot be made to validate:
tuples
use Types::Standard -all; my $tuples = array(1 .. 7)->tuples(2, Int);
my $matched = $array->grep(sub { $_[0] =~ /foo/ });
Returns a new array object consisting of the list of elements for which the given subroutine evaluated to true. $_[0] is the element being operated on; you can also use the topicalizer $_.
$_[0]
$_
my $arr = array( qw/ ab bc bd de / ); my $first = $arr->first(sub { $_ =~ /^b/ }); ## 'bc'
Returns the first element of the list for which the given sub evaluates to true. $_ is set to each element, in turn, until a match is found (or we run out of possibles).
Like "first", but return the index of the first successful match.
if ( $array->has_any(sub { $_ eq 'foo' }) ) { ... }
If passed no arguments, returns the same thing as "count".
If passed a sub, returns boolean true if the sub is true for any element of the array; see "any" in List::MoreUtils.
$_ is set to the element being operated upon.
my $after = array( 1 .. 10 )->items_after(sub { $_ == 5 }); ## $after contains [ 6, 7, 8, 9, 10 ]
Returns a new array object consisting of the elements of the original list that occur after the first position for which the given sub evaluates to true.
Like "items_after", but include the item that evaluated to true.
The opposite of "items_after".
The opposite of "items_after_incl".
my $lowercased = $array->map(sub { lc }); # Same as: my $lowercased = $array->map(sub { lc $_[0] });
Evaluates a given subroutine for each element of the array, and returns a new array object. $_[0] is the element being operated on; you can also use the topicalizer $_.
Also see "mapval".
my $orig = array(1, 2, 3); my $incr = $orig->mapval(sub { ++$_ }); $incr->all; # (2, 3, 4) $orig->all; # Still untouched
An alternative to "map". $_ is a copy, rather than an alias to the current element, and the result is retrieved from the altered $_ rather than the return value of the block.
This feature is borrowed from Data::Munge by Lukas Mai (CPAN: MAUKE).
my $iter = array( 1 .. 7 )->natatime(3); $iter->(); ## ( 1, 2, 3 ) $iter->(); ## ( 4, 5, 6 ) $iter->(); ## ( 7 ) array( 1 .. 7 )->natatime(3, sub { my @vals = @_; ... });
Returns an iterator that, when called, produces a list containing the next 'n' items.
If given a coderef as a second argument, it will be called against each bundled group.
my $sum = array(1,2,3)->reduce(sub { $_[0] + $_[1] });
Reduces the array by calling the given subroutine for each element of the list. See "reduce" in List::Util.
my $sorted = $array->sort(sub { $_[0] cmp $_[1] });
Returns a new array object consisting of the list sorted by the given subroutine. $_[0] and $_[1] are equivalent to $a and $b in a normal sort() call.
$_[1]
$a
$b
my $array = array( { id => 'a' }, { id => 'c' }, { id => 'b' }, ); my $sorted = $array->sort_by(sub { $_->{id} });
Returns a new array object consisting of the list of elements sorted via a stringy comparison using the given sub. See List::UtilsBy.
Like "sort_by", but using numerical comparison.
my $unique = $array->uniq;
Returns a new array object containing only unique elements from the original array.
my $array = array( { id => 'a' }, { id => 'a' }, { id => 'b' }, ); my $unique = $array->uniq_by(sub { $_->{id} });
Returns a new array object consisting of the list of elements for which the given sub returns unique values.
List::Objects::WithUtils
List::Objects::WithUtils::Array
List::Objects::WithUtils::Role::WithJunctions
List::Objects::WithUtils::Array::Immutable
List::Objects::WithUtils::Array::Typed
Data::Perl
List::Util
List::MoreUtils
List::UtilsBy
Jon Portnoy <avenj@cobaltirc.org>
Portions of this code are derived from Data::Perl by Matthew Phillips (CPAN: MATTP), haarg et al
Licensed under the same terms as Perl.
To install List::Objects::WithUtils, copy and paste the appropriate command in to your terminal.
cpanm
cpanm List::Objects::WithUtils
CPAN shell
perl -MCPAN -e shell install List::Objects::WithUtils
For more information on module installation, please visit the detailed CPAN module installation guide.