module std.stream

std.stream — operators on streams and the Broadcast hub (§10.3, §10.4, II.1/II.2; D-2600..D-2619).

Every operator is an ordinary generator (yield, for await) over its input stream, so it is lazy: nothing runs until the result is consumed, one element at a time (the producer of each stage is a task that suspends in yield until it is asked for the next element, D-2601). Operators take the stream by value and own it: dropping the result (or leaving a for await early) cancels every stage up to the source. Errors of the input stream pass through unchanged and end the result. x |> f(args) is f(x, args) (§10.3). Time based operators (batch, window, throttle, debounce) have the effect time.

Example:

use std.stream { map, filter, take }

fn nums() -> stream<i32> {
  for i in 1..=100 { yield i }
}

fn main() io {
  var out: List<i32> = []
  for await x in nums() |> filter(x => *x % 2 == 0) |> map(x => x * 10) |> take(3) {
    out.push(x)
  }
  print("{out}")
}

[20, 40, 60]

Типы

Функции