Futils

Functional utils

Examples:

All

Determines whether all elements of the array satisfies the predicate.

Futils\all(fn($x) => $x > 100)([101, 102, 103]) // => true

Always

Creates a function that always returns a given value.

Futils\always(true)() // => true

Any

Determines whether any element of the array satisfies the predicate.

Futils\any(fn($x) => $x == 100)([1, 2, 100]) // => true

Compose

Function composition (fn -> ... -> f2 -> f1).

Futils\compose(fn($x) => $x + 1, fn($x) => $x * 100)(2) // => 201

Contains

Check whether a value is contained in a array.

Futils\contains(1337)([1, 1337, 2]) // => true

Difference

Computes the difference of arrays.

Futils\difference([1, 2, 3, 4])([1, 2]) // => [3, 4]

Drop

Drops the first n elements off the front of the array.

Futils\drop(2)([1, 2, 3, 4]) // => [3, 4]

Filter

Filters elements of an array using a callback function.

Futils\filter(fn($x) => $x > 0)([-1, -2, 1, 2]) // => [1, 2]

Find

Find first element of the array satisfies the predicate.

Futils\find(fn($x) => $x > 10)([1, 2, 11]) // => 11

Flatten

Flattens nested arrays.

Futils\flatten([1, [2, [3, [4]]]]) // => [1, 2, 3, 4]

Has

Check if exists element with this key in array.

Futils\has("test")(["test" => 1]) // => true

Head

Get head of array.

Futils\head([1, 2, 3]) // => 1

IndexOf

Get first index of value in array.

Futils\indexOf("test")([1, "test", 3]) // => 1

Join

Join array elements with a string.

Futils\join([1, 2, 3])("|") // => "1|2|3"

Last

Get last element of array.

Futils\last([1, 2, 3, 4]) // => 4

Map

Applying function to each element of array.

Futils\map(fn($x) => $x + 1)([1, 2, 3]) // => [2, 3, 4]

Merge

Merge two arrays.

Futils\merge([1, 2])([3, 4]) // => [1, 2, 3, 4]

Partial

Create partial function.

Futils\partial(fn($x, $y, $z) => $x + $y + $z)(1, 2)(3) // => 6

Partition

Equivalent to [(filter f, arr), (reject f, arr)]

Futils\partition(fn($x) => $x > 0)([-1, -2, 1, 2]) // => [[1, 2], [-1, -2]]

Pipe

Function composition (f1 -> f2 -> ... -> fn).

Futils\pipe(fn($x) => $x + 1, fn($x) => $x * 100)(1) // => 200

Reduce

Reduce the array to a single value using a callback function.

Futils\reduce(fn($x, $y) => $x + $y)([1, 2, 3]) // => 6

Reject

Like filter, but the new array is composed of all the items which fail the function.

Futils\reject(fn($x) => $x > 0)([-1, -2, 1, 2]) // => [-1, -2]

Replace

Replaces elements from passed arrays into the first array.

Futils\replace([1, 2, 3])([1 => 3, 2 => 2]) // => [1, 3, 2]

Tail

Get tail of array

Futils\tail([1, 2, 3, 4, 5]) // => [2, 3, 4, 5]

Take

Get n first elements from array.

Futils\take(2)([1, 2, 3, 4]) // => [1, 2]

When

Only when predicate is true then appling function to argument, else return argument.

Futils\when(fn($x) => $x > 100)(fn($x) => $x + 5)(1000) // => 1005

Zip

Zips together its two arguments into a array of arrays.

Futils\zip([1, 2, 3])([4, 5, 6]) // => [[1, 4], [2, 5], [3, 6]]

Monads

IdentityMonad - Just annotates plain values and functions to satisfy the monad laws.

(new Futils\IdentityMonad(100))
    ->bind(fn($x, $n) => $x * $n, 2)
    ->bind("strval")
    ->extract() // => "200"

MaybeMonad - Encapsulates the type of an undefined value.

(new Futils\MaybeMonad("test"))
    ->bind(fn() => null)
    ->bind(fn($x) => $x + 1)
    ->extract() // => null

ListMonad - Abstracts away the concept of a list of items.

(new Futils\ListMonad([1, new IdentityMonad(2), new MaybeMonad(3), new ListMonad([4])]))
    ->bind(fn($x) => $x + 100)
    ->extract() // => [101, 102, 103, [104]]