runtime

Module nu.lang.runtime.

Runtime: how Nu programs run.

• runtime - Runtime: the concrete Runtime that drives compiled Programs.
• context - Context: the tagged value store the runtime drives against.
• utils - Budget, into_loop, safely_(a)closing: per-call resources and lifecycle helpers.

Sentinels (EMPTY / INVALID / Sentinel) live one level up as nu.lang.sentinels: they are value-space vocabulary, not runtime mechanics. Top-level entry points (run, eval, aeval, ...) live in nu.lang.helpers.

Call

into_loop

Run a coroutine to completion from sync code.

runtime.into_loop(coro)

Path nu.lang.runtime.into_loop. Defined on nu.lang.runtime.utils.loop, bound as a function. Builds T.

Spins a fresh loop with asyncio.run when no loop is running. Raises if called while a loop is already running - the caller should be using aeval directly in that case.

Arguments

Undocumented: example.

safely_aclosing

Async sibling of safely_closing: aclose on exit if present.

runtime.safely_aclosing(ait)

Path nu.lang.runtime.safely_aclosing. Defined on nu.lang.runtime.utils.loop, bound as a function. Builds AsyncIterator[AsyncIterable[T]].

Critical inside async generators that may short-circuit. Without this, CPython queues finalizer aclose Tasks on the running loop, retaining frames and Contexts until GC catches up - on a busy loop, an observable memory leak.

Arguments

Undocumented: example.

safely_closing

Yield it; on exit call close() if it has one, else no-op.

runtime.safely_closing(it)

Path nu.lang.runtime.safely_closing. Defined on nu.lang.runtime.utils.loop, bound as a function. Builds Iterator[Iterable[T]].

Use to wrap iteration when the iterable's concrete type is unknown - generators get finalized even on short-circuit (break, return, exception); lists and ranges pass through unchanged.

Arguments

Undocumented: example.