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Nim Writer

The Nim writer (headerkit.writers.nim) converts headerkit IR into native Nim binding modules supporting both C and C++ FFI.

Features

  • C Interoperability: Generates {.importc.} pragmas with struct/union/enum tag specifiers, cdecl calling conventions, and type mappings.
  • C++ Interoperability: Generates {.importcpp.} pragmas for C++ classes, single and polymorphic inheritance (object of RootObj), methods, constructors, destructors, and operators.
  • Templates & Generics: Emits parametric Nim object types and generic procs (e.g. Container[T]*).
  • Smart Pointers & Containers: Maps std::shared_ptr<T>, std::unique_ptr<T>, std::vector<T>, and std::string to Nim wrapper types.
  • Iterators: Generates idiomatic items iterators for C++ containers with begin()/end() methods.
  • Keyword & Identifier Escaping: Escapes Nim reserved keywords and formats identifiers safely.

Usage

headerkit mylib.h -w nim -o nim:mylib.nim

from headerkit.backends.libclang import LibclangBackend
from headerkit.writers.nim import NimWriter, write_nim

backend = LibclangBackend()
header = backend.parse(code, "mylib.h")

# Using NimWriter class
writer = NimWriter(header_path="mylib.h")
nim_code = writer.write(header)

# Or convenience helper
nim_code = write_nim(header, header_path="mylib.h")

Type Mappings

C / C++ Type Nim Type
void void
bool / _Bool bool
char / signed char cchar
unsigned char cuchar / uint8
short / unsigned short cshort / cushort
int / unsigned int cint / cuint
long / unsigned long clong / culong
long long / unsigned long long clonglong / culonglong
size_t / ssize_t csize_t / csSize
float / double cfloat / cdouble
const char * cstring
void * pointer
T * ptr T
T & var T
T && (rvalue ref) sink T
T[N] array[N, T]

API Reference

NimWriter 

NimWriter(*, header_path=None)

Bases: BaseWriter

Writer that converts headerkit IR into Nim binding modules.

hash_comment_format 

hash_comment_format()

Return format string for wrapping TOML cache metadata in Nim comments.

write_nim 

write_nim(header, *, header_path=None)

Convenience function to generate Nim bindings from a Header IR.