C interop

NanoC never needs to parse your headers. C functions, structs, macros and libraries are used as in C, and anything NanoC does not recognize passes through untouched.

Includes and libc

+stdlib
f main
  p: ptr = malloc(128)
  if p == NULL
    < 1
  free(p)
  < 0

#include <stdlib.h>

int main(void) {
    void *p = malloc(128);
    if (p == NULL) {
        return 1;
    }
    free(p);
    return 0;
}

+stdio,stdlib includes standard headers (bare names add .h). Use + <header.h> or + "local.h" for explicit forms. Preprocessor chains are written with indentation instead of #endif; see the preprocessor lesson.

Raw C islands

@c takes an indented block, a balanced { ... } or a quoted string and copies it verbatim, bypassing expansion. Use it for function pointer declarators, attributes and compiler extensions.

@c {
  static int apply(int (*fn)(int), int x) { return fn(x); }
}
f twice(x: i32) i32
  x * 2
f main
  `int (*fn)(int) = twice;`
  apply(fn, 21) != 42

  static int apply(int (*fn)(int), int x) { return fn(x); }

int twice(int x) {
    return x * 2;
}

int main(void) {
    int (*fn)(int) = twice;
    return apply(fn, 21) != 42;
}

Target: backtick inline C

The new core embeds C inline between backticks, without leaving the surrounding block.

f main
  n := 21
  `int doubled = n * 2;`
  doubled != 42

C++ and standards

--cpp emits C++17. --std c89|c99|c11|c17 selects output restrictions. User C must satisfy the chosen standard; NanoC does not rewrite it.