eb62813af5
"token" was overloaded (auth tokens, cgo handles, lexer tokens) and didn't say
what it is — a per-call correlation id linking an outgoing {.ffiHost.} call to
the answer that arrives later (possibly from another thread). Renamed across the
runtime (ffi_host / ffi_context), the macro, the exported C ABI (FFIHostFn,
<lib>_host_complete), the Go trampoline, and the tests; regenerated bindings.
The unrelated request-path cgo.Handle result-slot (also informally called a
"token" in go.nim comments) is left as-is — different mechanism.
16 host unit tests + the examples/host_demo Go round-trip stay green.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
timer example
This example is a self-contained Nimble project demonstrating how to import nim-ffi and use the .ffiCtor. / .ffi. abstraction.
Two ABIs, one library
Every generated library exports two ABIs side by side, and you choose per call site:
| ABI | Header / symbols | Use it for |
|---|---|---|
| Native (pure C) | <lib>.h / <name> |
Same-process / local calls. Flat C structs by value, zero serialization. |
| CBOR | <lib>_cbor.h / <name>_cbor |
Inter-process communication only — a different process or machine, where the request must be serialized to cross the boundary. |
In a shared address space the CBOR round-trip is pure overhead, so default to the native ABI locally and reach for CBOR only when you actually cross a process/machine boundary (see ipc/). The per-language examples below: native C (c_bindings/), native Go (go_bindings/), native/CBOR C++ (cpp_bindings/), CBOR Rust (rust_client/), and CBOR-over-socket IPC (ipc/).
Usage
-
Change into the example directory:
cd examples/timer -
Install the local
ffidependency:nimble install -y ../.. -
Build the example library:
nimble build -
Generate bindings:
nimble genbindings_rust nimble genbindings_cpp
Rust example clients
The Rust client lives in examples/timer/rust_client.
-
Run the sync example:
cd examples/timer/rust_client cargo run --bin rust_client -
Run the Tokio example:
cd examples/timer/rust_client cargo run --bin tokio_client
C++ example
The generated C++ example lives in examples/timer/cpp_bindings.
Build and run it with:
cd examples/timer/cpp_bindings
cmake -S . -B build
cmake --build build
./build/example