Hyperlinkv0.8.0-beta.28

Stream

Stream.splitconsteffect/Stream.ts:7208
<A, B extends A>(refinement: Refinement<NoInfer<A>, B>): <E, R>(
  self: Stream<A, E, R>
) => Stream<Arr.NonEmptyReadonlyArray<Exclude<A, B>>, E, R>
<A>(predicate: Predicate<NoInfer<A>>): <E, R>(
  self: Stream<A, E, R>
) => Stream<Arr.NonEmptyReadonlyArray<A>, E, R>
<A, E, R, B extends A>(
  self: Stream<A, E, R>,
  refinement: Refinement<A, B>
): Stream<Arr.NonEmptyReadonlyArray<Exclude<A, B>>, E, R>
<A, E, R>(self: Stream<A, E, R>, predicate: Predicate<A>): Stream<
  Arr.NonEmptyReadonlyArray<A>,
  E,
  R
>

Splits the stream into non-empty groups whenever the predicate matches.

Details

Matching elements act as delimiters and are not included in the output.

Example (Splitting on matching values)

import { Console, Effect, Stream } from "effect"

const program = Effect.gen(function*() {
  const result = yield* Stream.range(0, 9).pipe(
    Stream.split((n) => n % 4 === 0),
    Stream.runCollect
  )
  yield* Console.log(result)
})

Effect.runPromise(program)
// Output: [ [1, 2, 3], [5, 6, 7], [9] ]
grouping
Source effect/Stream.ts:720832 lines
export const split: {
  <A, B extends A>(
    refinement: Refinement<NoInfer<A>, B>
  ): <E, R>(self: Stream<A, E, R>) => Stream<Arr.NonEmptyReadonlyArray<Exclude<A, B>>, E, R>
  <A>(predicate: Predicate<NoInfer<A>>): <E, R>(self: Stream<A, E, R>) => Stream<Arr.NonEmptyReadonlyArray<A>, E, R>
  <A, E, R, B extends A>(
    self: Stream<A, E, R>,
    refinement: Refinement<A, B>
  ): Stream<Arr.NonEmptyReadonlyArray<Exclude<A, B>>, E, R>
  <A, E, R>(self: Stream<A, E, R>, predicate: Predicate<A>): Stream<Arr.NonEmptyReadonlyArray<A>, E, R>
} = dual(2, <A, E, R>(
  self: Stream<A, E, R>,
  predicate: Predicate<NoInfer<A>>
): Stream<Arr.NonEmptyReadonlyArray<A>, E, R> =>
  mapAccumArray(self, Arr.empty<A>, (acc, arr) => {
    const out = Arr.empty<Arr.NonEmptyReadonlyArray<A>>()
    for (let i = 0; i < arr.length; i++) {
      if (predicate(arr[i])) {
        if (Arr.isArrayNonEmpty(acc)) {
          out.push(acc)
          acc = []
        }
      } else {
        acc.push(arr[i])
      }
    }
    return [acc, out]
  }, {
    onHalt(arr) {
      return Arr.isArrayNonEmpty(arr) ? Arr.of(arr) : emptyArr
    }
  }))