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open Import
open Ast
module S = Set.Make (String)
let load_defs l =
let tbl = Predef.make_table () in
List.iter (
fun ((_, (k, pl, _), _) as td) ->
Hashtbl.add tbl k (List.length pl, Some td)
) l;
tbl
let keep_last_defined get_name l =
let _, l =
List.fold_right (
fun x (set, l) ->
let k = get_name x in
if S.mem k set then (set, l)
else (S.add k set, x :: l)
) l (S.empty, [])
in
l
let get_field_name : field -> string = function
`Field (_, (k, _, _), _) -> k
| `Inherit _ -> assert false
let get_variant_name : variant -> string = function
Variant (_, (k, _), _) -> k
| Inherit _ -> assert false
let expand ?(inherit_fields = true) ?(inherit_variants = true) tbl t0 =
let rec subst deref param (t : type_expr) : type_expr =
match t with
Sum (loc, vl, a) ->
let vl = List.concat_map (subst_variant param) vl in
let vl =
if inherit_variants then
keep_last_defined get_variant_name vl
else
vl
in
Sum (loc, vl, a)
| Record (loc, fl, a) ->
let fl = List.concat_map (subst_field param) fl in
let fl =
if inherit_fields then
keep_last_defined get_field_name fl
else
fl
in
Record (loc, fl, a)
| Tuple (loc, tl, a) ->
Tuple (
loc,
List.map (fun (loc, x, a) -> (loc, subst false param x, a)) tl, a
)
| List (loc, t, a)
| Name (loc, (_, "list", [t]), a) ->
List (loc, subst false param t, a)
| Option (loc, t, a)
| Name (loc, (_, "option", [t]), a) ->
Option (loc, subst false param t, a)
| Nullable (loc, t, a)
| Name (loc, (_, "nullable", [t]), a) ->
Nullable (loc, subst false param t, a)
| Shared (loc, t, a)
| Name (loc, (_, "shared", [t]), a) ->
Shared (loc, subst false param t, a)
| Wrap (loc, t, a)
| Name (loc, (_, "wrap", [t]), a) ->
Wrap (loc, subst false param t, a)
| Tvar (_, s) -> Option.value (List.assoc s param) ~default:t
| Name (loc, (loc2, k, args), a) ->
let expanded_args = List.map (subst false param) args in
if deref then
let _, vars, _, t =
try
match Hashtbl.find tbl k with
_, Some (_, (k, vars, a), t) -> k, vars, a, t
| _, None -> failwith ("Cannot inherit from type " ^ k)
with Not_found ->
failwith ("Missing type definition for " ^ k)
in
let param = List.combine vars expanded_args in
subst true param t
else
Name (loc, (loc2, k, expanded_args), a)
and subst_field param = function
`Field (loc, k, t) -> [ `Field (loc, k, subst false param t) ]
| `Inherit (_, t) as x ->
(match subst true param t with
Record (_, vl, _) ->
if inherit_fields then vl
else [ x ]
| _ -> failwith "Not a record type"
)
and subst_variant param = function
Variant (loc, k, opt_t) as x ->
(match opt_t with
None -> [ x ]
| Some t -> [ Variant (loc, k, Some (subst false param t)) ]
)
| Inherit (_, t) as x ->
(match subst true param t with
Sum (_, vl, _) ->
if inherit_variants then vl
else [ x ]
| _ -> failwith "Not a sum type"
)
in
subst false [] t0
let expand_module_body
?inherit_fields
?inherit_variants
(l : Ast.module_body) =
let td_list = List.map (function (Ast.Type td) -> td) l in
let tbl = load_defs td_list in
let td_list =
List.map (
fun (loc, name, t) ->
(loc, name, expand ?inherit_fields ?inherit_variants tbl t)
) td_list in
List.map (fun td -> Ast.Type td) td_list