ludic/docs/language/structure/kw-extern.md
Orkuncakilkaya 2e0047514b refactor(lang): rename builtins flr->floor and fx->fixed
De-abbreviate the two bare fixed-point conversion builtins:
  flr(f) -> int     ->  floor(f) -> int    (fixed -> int, flooring)
  fx(i)  -> fixed   ->  fixed(i) -> fixed  (int -> fixed; mirrors how the
                                            stringify builtin is `string`)

Updates the compiler dispatch, all call sites, the grammars/LSP/JetBrains
tokens, and the docs (fn-flr -> fn-floor, fn-fx -> fn-fixed). Reseeded;
C-free fixpoint holds; all suites green (45/24/29); site + check.py OK.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2026-08-30 02:01:56 +03:00

1.3 KiB


id: kw-extern name: extern category: structure kind: keyword tokens: extern sig: extern function name(a: T) -> R = "symbol" tip: Bind a name to an external native symbol — the seam for platform and library calls. order: 12

An extern function declares a function whose body lives outside Ludic and binds it to a native symbol resolved at link time. It is the seam through which Ludic reaches anything with a native interface — a system library, a math routine, or even another .ludic file compiled as a module. You write the Ludic signature you want to call and give the real symbol name after =; the linker connects them (pass -L/-l to ludicc to point at the library). Types must match the foreign ABI, so map each parameter and the return to the right Ludic type (int, fixed, pointer, …).

Parameters:

  • a — a typed argument passed straight through to the foreign symbol
program Physics {
  extern function c_hypot(a: fixed, b: fixed) -> fixed = "hypot_fx"

  property Velocity { delta_x: int = 0, delta_y: int = 0 }
  model Projectile { Velocity }

  handler MeasureSpeed phase Update {
    for (velocity) in query [Velocity, {Projectile}] {
      let speed = c_hypot(a: fixed(velocity.delta_x), b: fixed(velocity.delta_y))
      Screen.status(string(floor(speed)))
    }
  }
}