c-code

name	c-code
description	Guidance for editing C code in tibblify. Use when working in src/, adding C functions, or touching the C/R interface.

C code in tibblify

Directory layout

• src/ — tibblify's C code. Edit freely.
• src/rlang/ — vendored rlang C API. Do not edit directly.
• src/rlang-rcc.cpp and src/rlang.c — include points for vendored rlang. Do not edit directly.

Key files

File	Purpose
collector.h / collector.c	Collector structs — the core data structure
add-value.h / add-value.c	Adding values to collectors during parsing
parse-spec.h / parse-spec.c	Parsing tib_*() spec objects from R
tibblify.c	.Call() entry points
init.c	R_registerRoutines / R_useDynamicSymbols
finalize.c	Finalizing collectors into output

Building

devtools::load_all() compiles automatically. For a clean rebuild:

pkgbuild::compile_dll(debug = TRUE)

C APIs

• rlang C API: Headers live in src/rlang/ (e.g. rlang/rlang.h). PKG_CPPFLAGS = -I./rlang is set in Makevars.
• vctrs C API: Available via LinkingTo: vctrs; use vctrs/vctrs.h.

Registering a new C function

1. Write the C function; declare it in the corresponding .h file.
2. Add an entry to R_CallMethodDef CallEntries[] in init.c.
3. Add an R wrapper using .Call() in the appropriate R/ file.
4. Document the R wrapper using the document skill.

Visibility

Makevars sets -fvisibility=hidden. Only symbols listed in CallEntries are public — all other symbols are hidden by default.

Testing

All C code is tested through R wrappers in tests/testthat/. There are no standalone C tests; write R-level tests for every new C function.

Updating vendored rlang

Updating src/rlang/ is handled by the rlang-c.yaml workflow. To update manually, follow that workflow — do not hand-edit files in src/rlang/.