(* Title: HOL/Tools/BNF/bnf_lfp_compat.ML
Author: Jasmin Blanchette, TU Muenchen
Copyright 2013
Compatibility layer with the old datatype package.
*)
signature BNF_LFP_COMPAT =
sig
val datatype_compat_cmd : string list -> local_theory -> local_theory
end;
structure BNF_LFP_Compat : BNF_LFP_COMPAT =
struct
open Ctr_Sugar
open BNF_Util
open BNF_FP_Util
open BNF_FP_Def_Sugar
open BNF_FP_N2M_Sugar
val compatN = "compat_";
val code_nitpicksimp_simp_attrs = Code.add_default_eqn_attrib :: @{attributes [nitpick_simp, simp]};
(* TODO: graceful failure for local datatypes -- perhaps by making the command global *)
fun datatype_compat_cmd raw_fpT_names lthy =
let
val thy = Proof_Context.theory_of lthy;
fun not_datatype s = error (quote s ^ " is not a new-style datatype");
fun not_mutually_recursive ss =
error ("{" ^ commas ss ^ "} is not a complete set of mutually recursive new-style datatypes");
val (fpT_names as fpT_name1 :: _) =
map (fst o dest_Type o Proof_Context.read_type_name_proper lthy false) raw_fpT_names;
fun lfp_sugar_of s =
(case fp_sugar_of lthy s of
SOME (fp_sugar as {fp = Least_FP, ...}) => fp_sugar
| _ => not_datatype s);
val {ctr_sugars = fp_ctr_sugars, ...} = lfp_sugar_of fpT_name1;
val fpTs0 as Type (_, var_As) :: _ = map (body_type o fastype_of o hd o #ctrs) fp_ctr_sugars;
val fpT_names' = map (fst o dest_Type) fpTs0;
val _ = eq_set (op =) (fpT_names, fpT_names') orelse not_mutually_recursive fpT_names;
val (unsorted_As, _) = lthy |> mk_TFrees (length var_As);
val As = map2 (resort_tfree o Type.sort_of_atyp) var_As unsorted_As;
val fpTs as fpT1 :: _ = map (fn s => Type (s, As)) fpT_names';
fun nested_Tparentss_indicessss_of parent_Tkks (T as Type (s, _)) kk =
(case try lfp_sugar_of s of
SOME ({T = T0, fp_res = {Ts = mutual_Ts0, ...}, ctr_sugars, ...}) =>
let
val rho = Vartab.fold (cons o apsnd snd) (Sign.typ_match thy (T0, T) Vartab.empty) [];
val substT = Term.typ_subst_TVars rho;
val mutual_Ts = map substT mutual_Ts0;
val mutual_nn = length mutual_Ts;
val mutual_kks = kk upto kk + mutual_nn - 1;
val mutual_Tkks = mutual_Ts ~~ mutual_kks;
fun indices_of_ctr_arg parent_Tkks (U as Type (s, Us)) (accum as (Tparents_ksss, kk')) =
if s = @{type_name fun} then
if exists_subtype_in mutual_Ts U then
(warning "Incomplete support for recursion through functions -- \
\the old 'primrec' will fail";
indices_of_ctr_arg parent_Tkks (range_type U) accum)
else
([], accum)
else
(case AList.lookup (op =) (parent_Tkks @ mutual_Tkks) U of
SOME kk => ([kk], accum)
| NONE =>
if exists (exists_strict_subtype_in mutual_Ts) Us then
error "Deeply nested recursion not supported"
else if exists (member (op =) mutual_Ts) Us then
([kk'],
nested_Tparentss_indicessss_of parent_Tkks U kk' |>> append Tparents_ksss)
else
([], accum))
| indices_of_ctr_arg _ _ accum = ([], accum);
fun Tparents_indicesss_of_mutual_type T kk ctr_Tss =
let val parent_Tkks' = (T, kk) :: parent_Tkks in
fold_map (fold_map (indices_of_ctr_arg parent_Tkks')) ctr_Tss
#>> pair parent_Tkks'
end;
val ctrss = map #ctrs ctr_sugars;
val ctr_Tsss = map (map (binder_types o substT o fastype_of)) ctrss;
in
([], kk + mutual_nn)
|> fold_map3 Tparents_indicesss_of_mutual_type mutual_Ts mutual_kks ctr_Tsss
|> (fn (Tparentss_kkssss, (Tparentss_kkssss', kk)) =>
(Tparentss_kkssss @ Tparentss_kkssss', kk))
end
| NONE => error ("Unsupported recursion via type constructor " ^ quote s ^
" not corresponding to new-style datatype (cf. \"datatype_new\")"));
fun get_indices (Var ((_, kk), _)) = [kk];
val (Tparentss_kkssss, _) = nested_Tparentss_indicessss_of [] fpT1 0;
val Tparentss = map fst Tparentss_kkssss;
val Ts = map (fst o hd) Tparentss;
val kkssss = map snd Tparentss_kkssss;
val fp_sugars0 = map (lfp_sugar_of o fst o dest_Type) Ts;
val ctrss0 = map (#ctrs o of_fp_sugar #ctr_sugars) fp_sugars0;
val ctr_Tsss0 = map (map (binder_types o fastype_of)) ctrss0;
fun apply_comps n kk =
mk_partial_compN n (replicate n @{typ unit} ---> @{typ unit})
(Var ((Name.uu, kk), @{typ "unit => unit"}));
val callssss =
map2 (map2 (map2 (fn kks => fn ctr_T => map (apply_comps (num_binder_types ctr_T)) kks)))
kkssss ctr_Tsss0;
val b_names = Name.variant_list [] (map base_name_of_typ Ts);
val compat_b_names = map (prefix compatN) b_names;
val compat_bs = map Binding.name compat_b_names;
val common_name = compatN ^ mk_common_name b_names;
val nn_fp = length fpTs;
val nn = length Ts;
val ((fp_sugars, (lfp_sugar_thms, _)), lthy) =
if nn > nn_fp then
mutualize_fp_sugars Least_FP compat_bs Ts get_indices callssss fp_sugars0 lthy
else
((fp_sugars0, (NONE, NONE)), lthy);
val {ctr_sugars, co_inducts = [induct], co_inductss = inductss, co_iterss,
co_iter_thmsss = iter_thmsss, ...} :: _ = fp_sugars;
val inducts = map the_single inductss;
fun mk_dtyp [] (TFree a) = Datatype_Aux.DtTFree a
| mk_dtyp [] (Type (s, Ts)) = Datatype_Aux.DtType (s, map (mk_dtyp []) Ts)
| mk_dtyp [kk] (Type (@{type_name fun}, [T, T'])) =
Datatype_Aux.DtType (@{type_name fun}, [mk_dtyp [] T, mk_dtyp [kk] T'])
| mk_dtyp [kk] T = if nth Ts kk = T then Datatype_Aux.DtRec kk else mk_dtyp [] T;
fun mk_ctr_descr Ts kkss ctr0 =
mk_ctr Ts ctr0 |> (fn Const (s, T) => (s, map2 mk_dtyp kkss (binder_types T)));
fun mk_typ_descr kksss ((Type (T_name, Ts), kk) :: parents) ctrs0 =
(kk, (T_name, map (mk_dtyp (map snd (take 1 parents))) Ts, map2 (mk_ctr_descr Ts) kksss ctrs0));
val descr = map3 mk_typ_descr kkssss Tparentss ctrss0;
val recs = map (fst o dest_Const o co_rec_of) co_iterss;
val rec_thms = flat (map co_rec_of iter_thmsss);
fun mk_info ({T = Type (T_name0, _), index, ...} : fp_sugar) =
let
val {casex, exhaust, nchotomy, injects, distincts, case_thms, case_cong, weak_case_cong,
split, split_asm, ...} = nth ctr_sugars index;
in
(T_name0,
{index = index, descr = descr, inject = injects, distinct = distincts, induct = induct,
inducts = inducts, exhaust = exhaust, nchotomy = nchotomy, rec_names = recs,
rec_rewrites = rec_thms, case_name = fst (dest_Const casex), case_rewrites = case_thms,
case_cong = case_cong, weak_case_cong = weak_case_cong, split = split,
split_asm = split_asm})
end;
val infos = map mk_info (take nn_fp fp_sugars);
val all_notes =
(case lfp_sugar_thms of
NONE => []
| SOME ((induct_thms, induct_thm, induct_attrs), (fold_thmss, rec_thmss, _)) =>
let
val common_notes =
(if nn > 1 then [(inductN, [induct_thm], induct_attrs)] else [])
|> filter_out (null o #2)
|> map (fn (thmN, thms, attrs) =>
((Binding.qualify true common_name (Binding.name thmN), attrs), [(thms, [])]));
val notes =
[(foldN, fold_thmss, []),
(inductN, map single induct_thms, induct_attrs),
(recN, rec_thmss, code_nitpicksimp_simp_attrs)]
|> filter_out (null o #2)
|> maps (fn (thmN, thmss, attrs) =>
if forall null thmss then
[]
else
map2 (fn b_name => fn thms =>
((Binding.qualify true b_name (Binding.name thmN), attrs), [(thms, [])]))
compat_b_names thmss);
in
common_notes @ notes
end);
val register_interpret =
Datatype_Data.register infos
#> Datatype_Data.interpretation_data (Datatype_Aux.default_config, map fst infos)
in
lthy
|> Local_Theory.raw_theory register_interpret
|> Local_Theory.notes all_notes |> snd
end;
val _ =
Outer_Syntax.local_theory @{command_spec "datatype_compat"}
"register new-style datatypes as old-style datatypes"
(Scan.repeat1 Parse.type_const >> datatype_compat_cmd);
end;