map

map<S, A, B>(f): (st) => State<S, B>

Defined in: Core/State.ts:101

Transforms the value produced by a State computation. The state transformation is unchanged.

Type Parameters

S

S

A

A

B

B

Parameters

f

(a) => B

Returns

(st): State<S, B>

Parameters

st

State<S, A>

Returns

State<S, B>

Example

const readLength: State<string[], number> = pipe(
  State.get<string[]>(),
  State.map(stack => stack.length),
);

State.run(["a", "b", "c"])(readLength); // [3, ["a", "b", "c"]]