Different, not quite correct yet, but I think slightly closer to correct, approach to convincing the typechecker to get along with this new type grammar.

This commit is contained in:
Graydon Hoare 2010-06-29 18:25:16 -07:00
parent 2a00a61ef3
commit f05fc6b9d7

View File

@ -2,7 +2,7 @@ open Common;;
open Semant;;
type tyspec =
TYSPEC_equiv of tyvar
TYSPEC_equiv of (simpl * tyvar)
| TYSPEC_all
| TYSPEC_resolved of (Ast.ty_param array) * Ast.ty
| TYSPEC_callable of (tyvar * tyvar array) (* out, ins *)
@ -19,6 +19,10 @@ type tyspec =
| TYSPEC_vector of tyvar
| TYSPEC_app of (tyvar * Ast.ty array)
and simpl = SIMPL_none
| SIMPL_exterior
| SIMPL_mutable
and dict = (Ast.ident, tyvar) Hashtbl.t
and tyvar = tyspec ref;;
@ -101,7 +105,15 @@ let rec tyspec_to_str (ts:tyspec) : string =
else
Ast.fmt_ty ff ty
| TYSPEC_equiv tv ->
| TYSPEC_equiv (SIMPL_none, tv) ->
fmt_tyspec ff (!tv)
| TYSPEC_equiv (SIMPL_exterior, tv) ->
fmt ff "@";
fmt_tyspec ff (!tv)
| TYSPEC_equiv (SIMPL_mutable, tv) ->
fmt ff "mutable ";
fmt_tyspec ff (!tv)
| TYSPEC_callable (out, ins) ->
@ -156,7 +168,7 @@ let iflog cx thunk =
let rec resolve_tyvar (tv:tyvar) : tyvar =
match !tv with
TYSPEC_equiv subtv -> resolve_tyvar subtv
TYSPEC_equiv (_, subtv) -> resolve_tyvar subtv
| _ -> tv
;;
@ -243,20 +255,23 @@ let process_crate (cx:ctxt) (crate:Ast.crate) : unit =
*)
and unify_tyvars' (simplify:bool) (av:tyvar) (bv:tyvar) : unit =
let (a, b) = ((resolve_tyvar av), (resolve_tyvar bv)) in
let simplified tv =
let wrap tv =
match !tv with
TYSPEC_resolved (params_a, Ast.TY_mutable ty_a) ->
Some (ref (TYSPEC_resolved (params_a, ty_a)))
| TYSPEC_resolved (params_a, Ast.TY_exterior ty_a) ->
Some (ref (TYSPEC_resolved (params_a, ty_a)))
| _ -> None
TYSPEC_resolved (params, Ast.TY_mutable ty) ->
tv := TYSPEC_equiv (SIMPL_mutable,
(ref (TYSPEC_resolved (params, ty))));
true
| TYSPEC_resolved (params, Ast.TY_exterior ty) ->
tv := TYSPEC_equiv (SIMPL_exterior,
(ref (TYSPEC_resolved (params, ty))));
true
| _ -> false
in
if simplify
then
match (simplified a, simplified b) with
(Some a', _) -> unify_tyvars' simplify a' bv
| (_, Some b') -> unify_tyvars' simplify av b'
| (None, None) -> unify_tyvars'' av bv
if (wrap a) || (wrap b)
then unify_tyvars' simplify a b
else unify_tyvars'' a b
else
unify_tyvars'' av bv
@ -777,8 +792,8 @@ let process_crate (cx:ctxt) (crate:Ast.crate) : unit =
TYSPEC_vector av
in
let c = ref result in
a := TYSPEC_equiv c;
b := TYSPEC_equiv c
a := TYSPEC_equiv (SIMPL_none, c);
b := TYSPEC_equiv (SIMPL_none, c)
and unify_ty_parametric
(simplify:bool)
@ -1371,24 +1386,21 @@ let process_crate (cx:ctxt) (crate:Ast.crate) : unit =
| _ -> bug () "check_auto_tyvar: no slot defn"
in
let get_resolved_ty tv id =
let ts = !(resolve_tyvar tv) in
match ts with
TYSPEC_resolved ([||], ty) -> ty
| TYSPEC_vector (tv) ->
begin
match !(resolve_tyvar tv) with
TYSPEC_resolved ([||], ty) ->
(Ast.TY_vec ty)
| _ ->
err (Some id)
"unresolved vector-element type in %s (%d)"
(tyspec_to_str ts) (int_of_node id)
end
| _ -> err (Some id)
"unresolved type %s (%d)"
(tyspec_to_str ts)
(int_of_node id)
let rec get_resolved_ty tv id =
match !tv with
TYSPEC_resolved ([||], ty) -> ty
| TYSPEC_vector tv ->
Ast.TY_vec (get_resolved_ty tv id)
| TYSPEC_equiv (SIMPL_none, tv) ->
get_resolved_ty tv id
| TYSPEC_equiv (SIMPL_mutable, tv) ->
Ast.TY_mutable (get_resolved_ty tv id)
| TYSPEC_equiv (SIMPL_exterior, tv) ->
Ast.TY_exterior (get_resolved_ty tv id)
| _ -> err (Some id)
"unresolved type %s (%d)"
(tyspec_to_str !tv)
(int_of_node id)
in
let check_auto_tyvar id =