diff options
Diffstat (limited to 'src/rewrites.ml')
| -rw-r--r-- | src/rewrites.ml | 106 |
1 files changed, 91 insertions, 15 deletions
diff --git a/src/rewrites.ml b/src/rewrites.ml index 3b5a1736..2b5a1f94 100644 --- a/src/rewrites.ml +++ b/src/rewrites.ml @@ -2835,6 +2835,10 @@ let rec rewrite_defs_pat_string_append = | Pat_when (pat, guard, expr) -> (pat, [guard], expr) in + let builtins = [ + ("integer", ("maybe_atoi", int_typ)); + ] in + let (new_pat, new_guards, new_expr) = match (p_aux, p_annot) with (* @@ -2887,8 +2891,56 @@ let rec rewrite_defs_pat_string_append = pat2 => expr } *) - | P_string_append (P_aux (P_lit (L_aux (L_string s, _) as lit), _), pat2), p_annot -> - assert false + | P_string_append (P_aux (P_app (Id_aux (Id builtin_id, _), [x] ) , _), pat2), p_annot + when List.mem_assoc builtin_id builtins -> + + (* common things *) + let builtin_func, builtin_typ = List.assoc builtin_id builtins in + let s_id = mk_id ("_stringappend_" ^ (string_of_int !stringappend_counter) ^ "#") in + stringappend_counter := !stringappend_counter + 1; + let n_id = mk_id ("_stringappend_" ^ (string_of_int !stringappend_counter) ^ "#") in + stringappend_counter := !stringappend_counter + 1; + let len_id = mk_id ("_stringappend_" ^ (string_of_int !stringappend_counter) ^ "#") in + stringappend_counter := !stringappend_counter + 1; + let env = Env.add_local s_id (Immutable, string_typ) env in + let env = Env.add_local n_id (Immutable, builtin_typ) env in + let env = Env.add_local len_id (Immutable, nat_typ) env in + + (* construct drop expression -- string_drop(s#, len#) *) + let drop_exp = mk_exp (E_app (mk_id "string_drop", [mk_exp (E_id s_id); mk_exp (E_id len_id)])) in + (* construct func expression -- maybe_atoi s# *) + let func_exp = mk_exp (E_app (mk_id builtin_func, [mk_exp (E_id s_id)])) in + (* construct some pattern -- Some (n#, len#) *) + let some_exp = mk_pat (P_app (mk_id "Some", [mk_pat (P_id n_id); mk_pat (P_id len_id)])) in + (* construct None pattern *) + let none_exp = mk_pat (P_app (mk_id "None", [])) in + + (* construct the new guard *) + let guard_inner_match = construct_single_match drop_exp (strip_pat pat2) None in + let new_guard = mk_exp (E_case (func_exp, [ + mk_pexp (Pat_exp (some_exp, guard_inner_match)); + mk_pexp (Pat_exp (none_exp, mk_exp (E_lit (mk_lit (L_false))))) + ])) in + + (* construct the new match *) + let new_match = mk_exp (E_case (drop_exp, [ + mk_pexp (Pat_exp (strip_pat pat2, strip_exp expr)) + ])) in + + (* construct the new let *) + let new_binding = mk_exp (E_case (func_exp, [ + mk_pexp (Pat_exp (some_exp, mk_exp (E_tuple [ + mk_exp (E_id n_id); + mk_exp (E_id len_id) + ]))) + ])) in + let new_letbind = mk_letbind (mk_pat (P_tup [ + strip_pat x; mk_pat (P_id len_id) + ])) new_binding in + let new_let = mk_exp (E_let (new_letbind, new_match)) in + + (* construct final result *) + (mk_pat (P_id s_id)), new_guard :: (List.map strip_exp guards), new_let | P_string_append _, _ -> failwith ("encountered a variety of string append pattern that is not yet implemented: " ^ string_of_pat (P_aux (p_aux, p_annot))) @@ -2907,20 +2959,44 @@ let rec rewrite_defs_pat_string_append = let rewrite_defs_pat_lits = - let counter = ref 0 in - let rewrite_pat guards = function - | P_lit lit, p_annot -> - let env = env_of_annot p_annot in - let typ = typ_of_annot p_annot in - let id = mk_id ("p" ^ string_of_int !counter ^ "#") in - let guard = mk_exp (E_app_infix (mk_exp (E_id id), mk_id "==", mk_exp (E_lit lit))) in - let guard = check_exp (Env.add_local id (Immutable, typ) env) guard bool_typ in - guards := guard :: !guards; - incr counter; - P_aux (P_id id, p_annot) - | p_aux, p_annot -> P_aux (p_aux, p_annot) + let rewrite_pexp (Pat_aux (pexp_aux, annot) as pexp) = + let guards = ref [] in + let counter = ref 0 in + + let rewrite_pat = function + | P_lit lit, p_annot -> + let env = env_of_annot p_annot in + let typ = typ_of_annot p_annot in + let id = mk_id ("p" ^ string_of_int !counter ^ "#") in + let guard = mk_exp (E_app_infix (mk_exp (E_id id), mk_id "==", mk_exp (E_lit lit))) in + let guard = check_exp (Env.add_local id (Immutable, typ) env) guard bool_typ in + guards := guard :: !guards; + incr counter; + P_aux (P_id id, p_annot) + | p_aux, p_annot -> P_aux (p_aux, p_annot) + in + + match pexp_aux with + | Pat_exp (pat, exp) -> + begin + let pat = fold_pat { id_pat_alg with p_aux = rewrite_pat } pat in + match !guards with + | [] -> pexp + | (g :: gs) -> + let guard_annot = (fst annot, Some (env_of exp, bool_typ, no_effect)) in + Pat_aux (Pat_when (pat, List.fold_left (fun g g' -> E_aux (E_app (mk_id "and_bool", [g; g']), guard_annot)) g gs, exp), annot) + end + | Pat_when (pat, guard, exp) -> + begin + let pat = fold_pat { id_pat_alg with p_aux = rewrite_pat } pat in + let guard_annot = (fst annot, Some (env_of exp, bool_typ, no_effect)) in + Pat_aux (Pat_when (pat, List.fold_left (fun g g' -> E_aux (E_app (mk_id "and_bool", [g; g']), guard_annot)) guard !guards, exp), annot) + end in - pexp_rewriters (rewrite_pexp_with_guards rewrite_pat) + + let alg = { id_exp_alg with pat_aux = (fun (pexp_aux, annot) -> rewrite_pexp (Pat_aux (pexp_aux, annot))) } in + rewrite_defs_base { rewriters_base with rewrite_exp = (fun _ -> fold_exp alg) } + (* Now all expressions have no blocks anymore, any term is a sequence of let-expressions, * internal let-expressions, or internal plet-expressions ended by a term that does not |