mirror of
https://github.com/logos-messaging/nim-ffi.git
synced 2026-06-22 09:20:13 +00:00
556599787c
Increment 3: the {.ffiHost.} pragma. A bodyless
proc fetchToken(key: string): Future[Result[string, string]] {.ffiHost.}
expands into an async proc that resolves the thread-local host registry +
pending table, looks the fn up by snake_case wire name, allocates a token,
invokes the host with the raw request bytes, and awaits the answer.
This is the inverse of {.ffi.} and the first end-to-end use of the registry
(increment 1) + completion bridge (increment 2). First slice is deliberately
narrow — raw ABI, one string param, Future[Result[string, string]] — to prove
the round-trip with zero serialization; struct params/returns and the
{.ffiHost: cbor.} format arg are follow-ups.
The body reads two new threadvars (ffiCurrentHostRegistry / ffiCurrentPendingTable)
set by ffiThreadBody alongside ffiCurrentEventRegistry, so the user's signature
stays ctx-free. The host fn is invoked synchronously before the await, while the
string arg is still alive (honouring the "req valid only for the call" contract).
5 macro tests pass under orc+refc; host + ffi_context suites stay green.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>