[spectec] Fix resolution of argument syntax sugar in the case of forward uses

Author: rossberg

spectec/doc/example/output/NanoWasm.pdf

@@ -73,6 +73,18 @@ let rec typ_of_exp e =
   | IterE (e1, iter) -> IterT (typ_of_exp e1, iter)
   | StrE efs -> StrT (NoDots, [], map_nl_list typfield_of_expfield efs, NoDots)
   | AtomE atom -> AtomT atom
+  | SeqE [{it = VarE (id, []); at = at1; _}; {it = ParenE e1; at = at2; _}]
+    when at1.right = at2.left ->  (* HACK! *)
+    VarT (id, [ref (ExpA e1) $ e1.at])
+  | SeqE [{it = VarE (id, []); at = at1; _}; {it = TupE es; at = at2; _}]
+    when at1.right = at2.left ->  (* HACK! *)
+    VarT (id, List.map (fun ei -> ref (ExpA ei) $ ei.at) es)
+  | SeqE [{it = AtomE {it = Xl.Atom.Atom id; at; _}; at = at1; _}; {it = ParenE e1; at = at2; _}]
+    when at1.right = at2.left ->  (* HACK! *)
+    VarT (id $ at, [ref (ExpA e1) $ e1.at])
+  | SeqE [{it = AtomE {it = Xl.Atom.Atom id; at; _}; at = at1; _}; {it = TupE es; at = at2; _}]
+    when at1.right = at2.left ->  (* HACK! *)
+    VarT (id $ at, List.map (fun ei -> ref (ExpA ei) $ ei.at) es)
   | SeqE es -> SeqT (List.map typ_of_exp es)
   | InfixE (e1, atom, e2) -> InfixT (typ_of_exp e1, atom, typ_of_exp e2)
   | BrackE (l, e1, r) -> BrackT (l, typ_of_exp e1, r)
@@ -156,6 +168,18 @@ let rec sym_of_exp e =
   | NumE (op, `Nat n) -> NumG (op, n)
   | TextE s -> TextG s
   | EpsE -> EpsG
+  | SeqE [{it = VarE (id, []); at = at1; _}; {it = ParenE e1; at = at2; _}]
+    when at1.right = at2.left ->  (* HACK! *)
+    VarG (id, [ref (ExpA e1) $ e1.at])
+  | SeqE [{it = VarE (id, []); at = at1; _}; {it = TupE es; at = at2; _}]
+    when at1.right = at2.left ->  (* HACK! *)
+    VarG (id, List.map (fun ei -> ref (ExpA ei) $ ei.at) es)
+  | SeqE [{it = AtomE {it = Xl.Atom.Atom id; at; _}; at = at1; _}; {it = ParenE e1; at = at2; _}]
+    when at1.right = at2.left ->  (* HACK! *)
+    VarG (id $ at, [ref (ExpA e1) $ e1.at])
+  | SeqE [{it = AtomE {it = Xl.Atom.Atom id; at; _}; at = at1; _}; {it = TupE es; at = at2; _}]
+    when at1.right = at2.left ->  (* HACK! *)
+    VarG (id $ at, List.map (fun ei -> ref (ExpA ei) $ ei.at) es)
   | SeqE es -> SeqG (List.map (fun e -> Elem (sym_of_exp e)) es)
   | ParenE e1 -> ParenG (sym_of_exp e1)
   | TupE es -> TupG (List.map sym_of_exp es)

spectec/src/el/convert.ml

@@ -2222,6 +2222,10 @@ and elab_arg in_lhs env (a : arg) (p : Il.param) s : Il.arg list * Il.Subst.subs
   | ExpA {it = CallE (id, []); _}, Il.DefP _ -> a.it := DefA id
   | _, _ -> ()
   );
+  Debug.(log_at "el.elab_arg" a.at
+    (fun _ -> fmt "%s : %s" (el_arg a) (il_param p))
+    (fun (as', _) -> fmt "%s" (list il_arg as'))
+  ) @@ fun _ ->
   match !(a.it), (Il.Subst.subst_param s p).it with
   | ExpA e, Il.ExpP (x, t) ->
     let e' = checkpoint (elab_exp env e t) in