unless

unless<A, B>(predicate, onFalse): (value) => A | B

Defined in: Composition/unless.ts:20

Executes a function on the piped value if a predicate is NOT met, otherwise returns the value unchanged.

Type Parameters

A

A

B

B = A

Parameters

predicate

(value) => boolean

onFalse

(value) => B

Returns

(value) => A | B

Example

pipe(
  5,
  unless(n => n % 2 === 0, n => n * 2)
); // 10

pipe(
  4,
  unless(n => n % 2 === 0, n => n * 2)
); // 4

See

when for executing when a predicate is met