cdn77 / functions

0.2.11 2026-10-14 08:45 UTC

Requires

• php: ^8.4
• ext-ds: ^1

Requires (Dev)

• cdn77/coding-standard: ^7.0
• ergebnis/composer-normalize: ^2.23
• infection/infection: ^0.35.0
• phpstan/extension-installer: ^1.1
• phpstan/phpstan: ^2.0
• phpstan/phpstan-phpunit: ^2.0.0
• phpunit/phpunit: ^13.0
• shipmonk/composer-dependency-analyser: ^1.5

MIT

• Simon Podlipsky

• php
• functions
• generators
• ds
• noop
• never
• absurd

Published on Packagist.org on 2026-10-14 08:47 UTC

README

Functions

absurd()

Function that should have never been called. Useful for default case in exhaustive matching.

assert_return()

Asserts the value via the expression and returns it.

It's useful when you want to assert inline so for example you can keep the arrow function in place.

It uses native assert() internally.

use function Cdn77\Functions\assert_return;

array_map(
    fn (mixed $value) => new RequiresInt(assert_return($value, is_int(...))),
    [1, 2, 3]
);

noop()

Does nothing. Useful e.g. for match expression that currently supports single-line expressions in blocks.

match ($val) {
  '1' => throw new Exception,
  '2' => foo(),
  default => noop(),
};

Ds

mapFromEntries()

Creates a map from an iterable of entries.

use function Cdn77\Functions\mapFromEntries;

$map = mapFromEntries([
  ['foo', 'bar'],
  ['baz', 'qux'],
]);

assert($map->get('foo') === 'bar');

Map mutation helpers

These functions mutate the supplied Ds\Map and follow Java Map null and return-value rules.

Function	Behavior	Return value
mapPutIfAbsent($map, $key, $value)	Stores the value if the key is missing or mapped to null.	The previous value, or null.
mapCompute($map, $key, $computer)	Calls $computer($key, $currentValue), using null for a missing key. Stores a non-null result; removes the key for a null result.	The computed value, or null.
mapComputeIfAbsent($map, $key, $computer)	Calls $computer($key) only if the key is missing or mapped to null. Stores a non-null result; leaves the map unchanged for a null result.	The existing or computed value, or null.
mapComputeIfPresent($map, $key, $computer)	Calls $computer($key, $currentValue) only for a non-null current value. Stores a non-null result; removes the key for a null result.	The computed value, or null if skipped or removed.

Compute callbacks must not modify the same map during computation.

mappedMapsFromIterable()

Groups an iterable into a Map<K, Map<KInner, V>> using a mapper that returns nested Pairs.

use Ds\Pair;
use function Cdn77\Functions\mappedMapsFromIterable;

$map = mappedMapsFromIterable(
    ['a' => 1, 'b' => 2, 'c' => 1],
    static fn (string $key, int $value) => new Pair($value, new Pair($key, $key . '_')),
);

assert($map->get(1)->get('a') === 'a_');
assert($map->get(1)->get('c') === 'c_');
assert($map->get(2)->get('b') === 'b_');

Iterable

find()

Finds a value in an iterable.

use function Cdn77\Functions\Iterable\find;

$iterable = [0, 1, 2, 3];
$option = find($iterable, static fn (mixed $_, int $value) => $value < 2);

assert($option->unwrap() === 0);