1.5 KiB
echo — CBOR-free abi = c C bindings
Generated by nimble genbindings_c_abi_echo (-d:targetLang=c_abi), this is the
pure C ABI rendering of the echo library, meant to be read side-by-side with
the CBOR rendering in ../c_bindings/ (issue #105).
../c_bindings/ (-d:targetLang=c) |
this dir (-d:targetLang=c_abi) |
|
|---|---|---|
| Wire format on the C side | CBOR | flat C structs (no serialization) |
| Third-party dependency | vendored TinyCBOR | none |
| Files | echo.h + nim_ffi_cbor.h + nim_ffi_prelude.h |
one self-contained echo.h |
| String type | NimFfiStr (owned) |
const char* (borrowed for the call) |
Both talk to the same unmodified Nim dylib API shape (echo_ctx_create,
echo_ctx_shout, …) and share the async, binding-owned callback contract. The
difference is only the ABI at the boundary: here the macro-generated _CWire
structs (ShoutRequest { const char* text; }, …) are passed as native C structs
and the Nim side converts them to/from Nim objects. CBOR is still used, but only
as an internal transport between the exported wrapper and the FFI worker thread —
it never appears in this header.
The library is built with -d:ffiEchoAbiC, which flips the shared
examples/echo/echo.nim source to declareLibrary(..., defaultABIFormat = "c").
A library that always wants the C ABI would set that in its own declareLibrary
call and need no extra flag.
Run the end-to-end test with nimble test_c_abi_e2e.