# next Alias for `resume` — advance a suspended coroutine/generator and return the next yielded value. Use it to drive `spawn`ed coroutines or `defcoro`/`@generator` functions one step at a time. ## Syntax

[next $gen]

## Parameters - `$gen` — A coroutine value (from `spawn`, `defcoro`, or `@generator`). ## Examples

def gen [spawn {||
    [yield :a]
    [yield :b]
}]

[next $gen]   # → :a
[next $gen]   # → :b
[next $gen]   # → nil  (finished)

## Returns The value yielded by the coroutine, or its final result when the body completes; nil once the coroutine is done or when `$gen` is not a coroutine. Resuming an already-finished coroutine keeps returning nil. ## See Also `resume`, `spawn`, `yield`, `coro-state`, `defcoro`