giles 7773c40337 ocaml: phase 4 basic labeled / optional argument syntax (label dropped) (+3 tests, 562 total) ...

Three parser changes:

  1. at-app-start? returns true on op '~' or '?' so the app loop
     keeps consuming labeled args.
  2. The app arg parser handles:
       ~name:VAL    drop label, parse VAL as the arg
       ?name:VAL    same
       ~name        punning -- treat as (:var name)
       ?name        same
  3. try-consume-param! drops '~' or '?' and treats the following
     ident as a regular positional param name.

Caveats:
  - Order in the call must match definition order; we don't reorder
    by label name.
  - Optional args don't auto-wrap in Some, so the function body sees
    the raw value for ?x:V.

Lets us write idiomatic-looking OCaml even though the runtime is
positional underneath:

  let f ~x ~y = x + y in f ~x:3 ~y:7         = 10
  let x = 4 in let y = 5 in f ~x ~y          = 20  (punning)
  let f ?x ~y = x + y in f ?x:1 ~y:2         = 3

2026-05-09 05:12:34 +00:00

80 KiB

Raw Blame History

View Raw