Creates a fresh source on the first read of each execution.
The factory may return a source directly or a PromiseLike that resolves to one. Pass context.signal to any external I/O so cancellation can abort in-flight setup. Use context.acquire(acquire, release) for resources opened during setup; plain sources returned after cancellation are never opened or closed by the library.
Creates a fresh source on the first read of each execution.
The factory may return a source directly or a
PromiseLikethat resolves to one. Passcontext.signalto any external I/O so cancellation can abort in-flight setup. Usecontext.acquire(acquire, release)for resources opened during setup; plain sources returned after cancellation are never opened or closed by the library.