f08cb7971d
- Add the `-d:ffiMode=native|cbor|both` strdefine (default both) with `ffiEmitNative`/`ffiEmitCbor` helpers; the C generator now emits only the selected header(s) (`<lib>.h` and/or `<lib>_cbor.h`). - Native C events: the native header documents each event's payload type (`"on_echo_fired" -> const EchoEvent *`) so consumers cast the callback's msg to the typed struct — the bare native listener already delivers it. - nimble tasks: `genbindings_c` (both), `genbindings_c_native`, `genbindings_c_cbor`. Verified: native mode emits only my_timer.h, cbor only my_timer_cbor.h, both emits both. 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