(***********************************************************************) (* *) (* OCaml *) (* *) (* Jerome Vouillon, projet Cristal, INRIA Rocquencourt *) (* OCaml port by John Malecki and Xavier Leroy *) (* *) (* Copyright 1996 Institut National de Recherche en Informatique et *) (* en Automatique. All rights reserved. This file is distributed *) (* under the terms of the Q Public License version 1.0. *) (* *) (***********************************************************************) (************************ Simple pattern matching **********************) open Debugger_config (*open Primitives*) open Misc (*open Const*) (*open Globals*) (*open Builtins*) open Typedtree (*open Modules*) (*open Symtable*) (*open Value*) open Parser_aux (* let rec find_constr tag = function [] -> fatal_error "find_constr: unknown constructor for this type" | constr::rest -> match constr.info.cs_tag with ConstrRegular(t, _) -> if t == tag then constr else find_constr tag rest | ConstrExtensible _ -> fatal_error "find_constr: extensible" let find_exception tag = let (qualid, stamp) = get_exn_of_num tag in let rec select_exn = function [] -> raise Not_found | constr :: rest -> match constr.info.cs_tag with ConstrExtensible(_,st) -> if st == stamp then constr else select_exn rest | ConstrRegular(_,_) -> fatal_error "find_exception: regular" in select_exn(hashtbl__find_all (find_module qualid.qual).mod_constrs qualid.id) *) let error_matching () = prerr_endline "Pattern matching failed"; raise Toplevel (* let same_name {qualid = name1} = function GRname name2 -> (name2 = "") || (name1.id = name2) | GRmodname name2 -> name1 = name2 let check_same_constr constr constr2 = try if not (same_name constr constr2) then error_matching () with Desc_not_found -> prerr_endline "Undefined constructor."; raise Toplevel *) let rec pattern_matching pattern obj ty = match pattern with P_dummy -> [] | P_variable var -> [var, obj, ty] | _ -> match (Ctype.repr ty).desc with Tvar | Tarrow _ -> error_matching () | Ttuple(ty_list) -> (match pattern with P_tuple pattern_list -> pattern_matching_list pattern_list obj ty_list | P_nth (n, patt) -> if n >= List.length ty_list then (prerr_endline "Out of range."; raise Toplevel); pattern_matching patt (Debugcom.get_field obj n) (List.nth ty_list n) | _ -> error_matching ()) | Tconstr(cstr, [ty_arg],_) when same_type_constr cstr constr_type_list -> (match pattern with P_list pattern_list -> let (last, list) = it_list (fun (current, list) pattern -> if value_tag current = 0 then error_matching (); (Debugcom.get_field current 1, (pattern, Debugcom.get_field current 0)::list)) (obj, []) pattern_list in if value_tag last <> 0 then error_matching (); flat_map (function (x, y) -> pattern_matching x y ty_arg) (rev list) | P_nth (n, patt) -> let rec find k current = if value_tag current = 0 then (prerr_endline "Out of range."; raise Toplevel); if k = 0 then pattern_matching patt (Debugcom.get_field current 0) ty_arg else find (k - 1) (Debugcom.get_field current 1) in find n obj | P_concat (pattern1, pattern2) -> if value_tag obj == 0 then error_matching (); (pattern_matching pattern1 (Debugcom.get_field obj 0) ty_arg) @ (pattern_matching pattern2 (Debugcom.get_field obj 1) ty) | _ -> error_matching ()) | Tconstr(cstr, [ty_arg]) when same_type_constr cstr constr_type_vect -> (match pattern with P_nth (n, patt) -> if n >= value_size obj then (prerr_endline "Out of range."; raise Toplevel); pattern_matching patt (Debugcom.get_field obj n) ty_arg | _ -> error_matching ()) | Tconstr(cstr, ty_list) -> (match cstr.info.ty_abbr with Tabbrev(params, body) -> pattern_matching pattern obj (expand_abbrev params body ty_list) | _ -> match_concrete_type pattern obj cstr ty ty_list) and match_concrete_type pattern obj cstr ty ty_list = let typ_descr = type_descr_of_type_constr cstr in match typ_descr.info.ty_desc with Abstract_type -> error_matching () | Variant_type constr_list -> let tag = value_tag obj in (try let constr = if same_type_constr cstr constr_type_exn then find_exception tag else find_constr tag constr_list in let (ty_res, ty_arg) = type_pair_instance (constr.info.cs_res, constr.info.cs_arg) in filter (ty_res, ty); match constr.info.cs_kind with Constr_constant -> error_matching () | Constr_regular -> (match pattern with P_constr (constr2, patt) -> check_same_constr constr constr2; pattern_matching patt (Debugcom.get_field obj 0) ty_arg | _ -> error_matching ()) | Constr_superfluous n -> (match pattern with P_constr (constr2, patt) -> check_same_constr constr constr2; (match patt with P_tuple pattern_list -> pattern_matching_list pattern_list obj (filter_product n ty_arg) | P_nth (n2, patt) -> let ty_list = filter_product n ty_arg in if n2 >= n then (prerr_endline "Out of range."; raise Toplevel); pattern_matching patt (Debugcom.get_field obj n2) (List.nth ty_list n2) | P_variable var -> [var, obj, {typ_desc = Tproduct (filter_product n ty_arg); typ_level = generic}] | P_dummy -> [] | _ -> error_matching ()) | _ -> error_matching ()) with Not_found -> error_matching () | Unify -> fatal_error "pattern_matching: types should match") | Record_type label_list -> let match_field (label, patt) = let lbl = try primitives__find (function l -> same_name l label) label_list with Not_found -> prerr_endline "Label not found."; raise Toplevel in let (ty_res, ty_arg) = type_pair_instance (lbl.info.lbl_res, lbl.info.lbl_arg) in (try filter (ty_res, ty) with Unify -> fatal_error "pattern_matching: types should match"); pattern_matching patt (Debugcom.get_field obj lbl.info.lbl_pos) ty_arg in (match pattern with P_record pattern_label_list -> flat_map match_field pattern_label_list | _ -> error_matching ()) | Abbrev_type(_,_) -> fatal_error "pattern_matching: abbrev type" and pattern_matching_list pattern_list obj ty_list = let val_list = try pair__combine (pattern_list, ty_list) with Invalid_argument _ -> error_matching () in flat_map (function (x, y, z) -> pattern_matching x y z) (rev (snd (it_list (fun (num, list) (pattern, typ) -> (num + 1, (pattern, Debugcom.get_field obj num, typ)::list)) (0, []) val_list)))