Generators

Generators produce lazy sequences.

Generator arrow syntax

numbers = *(): Sequence<Number> => {
  yield 1
  yield 2
  yield 3
}

Key rules

• generator arrows return Sequence<T>
• yield values must match the sequence element type
• generators are intended for pure lazy iteration in Draft 0.1
• yielding effectful work is a type or effect error

Why the rules are strict

FScript keeps generators separate from async streaming so the semantics stay predictable. They model lazy pure production, not background IO.

Comparison to JavaScript

The syntax will look familiar, but the role is narrower and more disciplined than JS generators.