method

List.first

List.first(s) -> T

Returns element 0 of s — the same as s[0], named for readability. The slice must hold at least one element; calling it on an empty slice reads out of bounds, so guard with List.len(s) > 0 when that is possible. Use it to peek at the head of a queue or the front of an ordered list.

Parameters

sa non-empty slice

Example

program Queue {
  var waiting: []int = new []int

  handler Serve phase Update {
    if List.len(waiting) > 0 {
      let next = List.first(waiting)
    }
  }
}

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