(* Title: HOL/Tools/Datatype/datatype_codegen.ML
Author: Stefan Berghofer and Florian Haftmann, TU Muenchen
Code generator facilities for inductive datatypes.
*)
signature DATATYPE_CODEGEN =
sig
val setup: theory -> theory
end;
structure Datatype_Codegen : DATATYPE_CODEGEN =
struct
(** generic code generator **)
(* liberal addition of code data for datatypes *)
fun mk_constr_consts thy vs tyco cos =
let
val cs = map (fn (c, tys) => (c, tys ---> Type (tyco, map TFree vs))) cos;
val cs' = map (fn c_ty as (_, ty) => (AxClass.unoverload_const thy c_ty, ty)) cs;
in if is_some (try (Code.constrset_of_consts thy) cs')
then SOME cs
else NONE
end;
(* case certificates *)
fun mk_case_cert thy tyco =
let
val raw_thms =
(#case_rewrites o Datatype_Data.the_info thy) tyco;
val thms as hd_thm :: _ = raw_thms
|> Conjunction.intr_balanced
|> Thm.unvarify_global
|> Conjunction.elim_balanced (length raw_thms)
|> map Simpdata.mk_meta_eq
|> map Drule.zero_var_indexes
val params = fold_aterms (fn (Free (v, _)) => insert (op =) v
| _ => I) (Thm.prop_of hd_thm) [];
val rhs = hd_thm
|> Thm.prop_of
|> Logic.dest_equals
|> fst
|> Term.strip_comb
|> apsnd (fst o split_last)
|> list_comb;
val lhs = Free (Name.variant params "case", Term.fastype_of rhs);
val asm = (Thm.cterm_of thy o Logic.mk_equals) (lhs, rhs);
in
thms
|> Conjunction.intr_balanced
|> MetaSimplifier.rewrite_rule [(Thm.symmetric o Thm.assume) asm]
|> Thm.implies_intr asm
|> Thm.generalize ([], params) 0
|> AxClass.unoverload thy
|> Thm.varifyT_global
end;
(* equality *)
fun mk_eq_eqns thy tyco =
let
val (vs, cos) = Datatype_Data.the_spec thy tyco;
val { descr, index, inject = inject_thms, distinct = distinct_thms, ... } =
Datatype_Data.the_info thy tyco;
val ty = Type (tyco, map TFree vs);
fun mk_eq (t1, t2) = Const (@{const_name HOL.equal}, ty --> ty --> HOLogic.boolT)
$ t1 $ t2;
fun true_eq t12 = HOLogic.mk_eq (mk_eq t12, HOLogic.true_const);
fun false_eq t12 = HOLogic.mk_eq (mk_eq t12, HOLogic.false_const);
val triv_injects = map_filter
(fn (c, []) => SOME (HOLogic.mk_Trueprop (true_eq (Const (c, ty), Const (c, ty))))
| _ => NONE) cos;
fun prep_inject (trueprop $ (equiv $ (_ $ t1 $ t2) $ rhs)) =
trueprop $ (equiv $ mk_eq (t1, t2) $ rhs);
val injects = map prep_inject (nth (Datatype_Prop.make_injs [descr] vs) index);
fun prep_distinct (trueprop $ (not $ (_ $ t1 $ t2))) =
[trueprop $ false_eq (t1, t2), trueprop $ false_eq (t2, t1)];
val distincts = maps prep_distinct (snd (nth (Datatype_Prop.make_distincts [descr] vs) index));
val refl = HOLogic.mk_Trueprop (true_eq (Free ("x", ty), Free ("x", ty)));
val simpset = Simplifier.global_context thy (HOL_basic_ss addsimps
(map Simpdata.mk_eq (@{thm equal} :: @{thm eq_True} :: inject_thms @ distinct_thms)));
fun prove prop = Skip_Proof.prove_global thy [] [] prop (K (ALLGOALS (simp_tac simpset)))
|> Simpdata.mk_eq;
in (map prove (triv_injects @ injects @ distincts), prove refl) end;
fun add_equality vs tycos thy =
let
fun add_def tyco lthy =
let
val ty = Type (tyco, map TFree vs);
fun mk_side const_name = Const (const_name, ty --> ty --> HOLogic.boolT)
$ Free ("x", ty) $ Free ("y", ty);
val def = HOLogic.mk_Trueprop (HOLogic.mk_eq
(mk_side @{const_name HOL.equal}, mk_side @{const_name HOL.eq}));
val def' = Syntax.check_term lthy def;
val ((_, (_, thm)), lthy') = Specification.definition
(NONE, (Attrib.empty_binding, def')) lthy;
val ctxt_thy = ProofContext.init_global (ProofContext.theory_of lthy);
val thm' = singleton (ProofContext.export lthy' ctxt_thy) thm;
in (thm', lthy') end;
fun tac thms = Class.intro_classes_tac []
THEN ALLGOALS (ProofContext.fact_tac thms);
fun prefix tyco = Binding.qualify true (Long_Name.base_name tyco) o Binding.qualify true "eq" o Binding.name;
fun add_eq_thms tyco =
Theory.checkpoint
#> `(fn thy => mk_eq_eqns thy tyco)
#-> (fn (thms, thm) => PureThy.note_thmss Thm.lemmaK
[((prefix tyco "refl", [Code.add_nbe_default_eqn_attribute]), [([thm], [])]),
((prefix tyco "simps", [Code.add_default_eqn_attribute]), [(rev thms, [])])])
#> snd
in
thy
|> Class.instantiation (tycos, vs, [HOLogic.class_equal])
|> fold_map add_def tycos
|-> (fn def_thms => Class.prove_instantiation_exit_result (map o Morphism.thm)
(fn _ => fn def_thms => tac def_thms) def_thms)
|-> (fn def_thms => fold Code.del_eqn def_thms)
|> fold add_eq_thms tycos
end;
(* register a datatype etc. *)
fun add_all_code config tycos thy =
let
val (vs :: _, coss) = (split_list o map (Datatype_Data.the_spec thy)) tycos;
val any_css = map2 (mk_constr_consts thy vs) tycos coss;
val css = if exists is_none any_css then []
else map_filter I any_css;
val case_rewrites = maps (#case_rewrites o Datatype_Data.the_info thy) tycos;
val certs = map (mk_case_cert thy) tycos;
val tycos_eq = filter_out
(fn tyco => can (Sorts.mg_domain (Sign.classes_of thy) tyco) [HOLogic.class_equal]) tycos;
in
if null css then thy
else thy
|> tap (fn _ => Datatype_Aux.message config "Registering datatype for code generator ...")
|> fold Code.add_datatype css
|> fold_rev Code.add_default_eqn case_rewrites
|> fold Code.add_case certs
|> not (null tycos_eq) ? add_equality vs tycos_eq
end;
(** SML code generator **)
open Codegen;
(* datatype definition *)
fun add_dt_defs thy defs dep module descr sorts gr =
let
val descr' = filter (can (map Datatype_Aux.dest_DtTFree o #2 o snd)) descr;
val rtnames = map (#1 o snd) (filter (fn (_, (_, _, cs)) =>
exists (exists Datatype_Aux.is_rec_type o snd) cs) descr');
val (_, (tname, _, _)) :: _ = descr';
val node_id = tname ^ " (type)";
val module' = if_library (thyname_of_type thy tname) module;
fun mk_dtdef prfx [] gr = ([], gr)
| mk_dtdef prfx ((_, (tname, dts, cs))::xs) gr =
let
val tvs = map Datatype_Aux.dest_DtTFree dts;
val cs' = map (apsnd (map (Datatype_Aux.typ_of_dtyp descr sorts))) cs;
val ((_, type_id), gr') = mk_type_id module' tname gr;
val (ps, gr'') = gr' |>
fold_map (fn (cname, cargs) =>
fold_map (invoke_tycodegen thy defs node_id module' false)
cargs ##>>
mk_const_id module' cname) cs';
val (rest, gr''') = mk_dtdef "and " xs gr''
in
(Pretty.block (str prfx ::
(if null tvs then [] else
[mk_tuple (map str tvs), str " "]) @
[str (type_id ^ " ="), Pretty.brk 1] @
flat (separate [Pretty.brk 1, str "| "]
(map (fn (ps', (_, cname)) => [Pretty.block
(str cname ::
(if null ps' then [] else
flat ([str " of", Pretty.brk 1] ::
separate [str " *", Pretty.brk 1]
(map single ps'))))]) ps))) :: rest, gr''')
end;
fun mk_constr_term cname Ts T ps =
flat (separate [str " $", Pretty.brk 1]
([str ("Const (\"" ^ cname ^ "\","), Pretty.brk 1,
mk_type false (Ts ---> T), str ")"] :: ps));
fun mk_term_of_def gr prfx [] = []
| mk_term_of_def gr prfx ((_, (tname, dts, cs)) :: xs) =
let
val cs' = map (apsnd (map (Datatype_Aux.typ_of_dtyp descr sorts))) cs;
val dts' = map (Datatype_Aux.typ_of_dtyp descr sorts) dts;
val T = Type (tname, dts');
val rest = mk_term_of_def gr "and " xs;
val (eqs, _) = fold_map (fn (cname, Ts) => fn prfx =>
let val args = map (fn i =>
str ("x" ^ string_of_int i)) (1 upto length Ts)
in (Pretty.blk (4,
[str prfx, mk_term_of gr module' false T, Pretty.brk 1,
if null Ts then str (snd (get_const_id gr cname))
else parens (Pretty.block
[str (snd (get_const_id gr cname)),
Pretty.brk 1, mk_tuple args]),
str " =", Pretty.brk 1] @
mk_constr_term cname Ts T
(map2 (fn x => fn U => [Pretty.block [mk_term_of gr module' false U,
Pretty.brk 1, x]]) args Ts)), " | ")
end) cs' prfx
in eqs @ rest end;
fun mk_gen_of_def gr prfx [] = []
| mk_gen_of_def gr prfx ((i, (tname, dts, cs)) :: xs) =
let
val tvs = map Datatype_Aux.dest_DtTFree dts;
val Us = map (Datatype_Aux.typ_of_dtyp descr sorts) dts;
val T = Type (tname, Us);
val (cs1, cs2) =
List.partition (exists Datatype_Aux.is_rec_type o snd) cs;
val SOME (cname, _) = Datatype_Aux.find_shortest_path descr i;
fun mk_delay p = Pretty.block
[str "fn () =>", Pretty.brk 1, p];
fun mk_force p = Pretty.block [p, Pretty.brk 1, str "()"];
fun mk_constr s b (cname, dts) =
let
val gs = map (fn dt => mk_app false (mk_gen gr module' false rtnames s
(Datatype_Aux.typ_of_dtyp descr sorts dt))
[str (if b andalso Datatype_Aux.is_rec_type dt then "0"
else "j")]) dts;
val Ts = map (Datatype_Aux.typ_of_dtyp descr sorts) dts;
val xs = map str
(Datatype_Prop.indexify_names (replicate (length dts) "x"));
val ts = map str
(Datatype_Prop.indexify_names (replicate (length dts) "t"));
val (_, id) = get_const_id gr cname
in
mk_let
(map2 (fn p => fn q => mk_tuple [p, q]) xs ts ~~ gs)
(mk_tuple
[case xs of
_ :: _ :: _ => Pretty.block
[str id, Pretty.brk 1, mk_tuple xs]
| _ => mk_app false (str id) xs,
mk_delay (Pretty.block (mk_constr_term cname Ts T
(map (single o mk_force) ts)))])
end;
fun mk_choice [c] = mk_constr "(i-1)" false c
| mk_choice cs = Pretty.block [str "one_of",
Pretty.brk 1, Pretty.blk (1, str "[" ::
flat (separate [str ",", Pretty.fbrk]
(map (single o mk_delay o mk_constr "(i-1)" false) cs)) @
[str "]"]), Pretty.brk 1, str "()"];
val gs = maps (fn s =>
let val s' = strip_tname s
in [str (s' ^ "G"), str (s' ^ "T")] end) tvs;
val gen_name = "gen_" ^ snd (get_type_id gr tname)
in
Pretty.blk (4, separate (Pretty.brk 1)
(str (prfx ^ gen_name ^
(if null cs1 then "" else "'")) :: gs @
(if null cs1 then [] else [str "i"]) @
[str "j"]) @
[str " =", Pretty.brk 1] @
(if not (null cs1) andalso not (null cs2)
then [str "frequency", Pretty.brk 1,
Pretty.blk (1, [str "[",
mk_tuple [str "i", mk_delay (mk_choice cs1)],
str ",", Pretty.fbrk,
mk_tuple [str "1", mk_delay (mk_choice cs2)],
str "]"]), Pretty.brk 1, str "()"]
else if null cs2 then
[Pretty.block [str "(case", Pretty.brk 1,
str "i", Pretty.brk 1, str "of",
Pretty.brk 1, str "0 =>", Pretty.brk 1,
mk_constr "0" true (cname, the (AList.lookup (op =) cs cname)),
Pretty.brk 1, str "| _ =>", Pretty.brk 1,
mk_choice cs1, str ")"]]
else [mk_choice cs2])) ::
(if null cs1 then []
else [Pretty.blk (4, separate (Pretty.brk 1)
(str ("and " ^ gen_name) :: gs @ [str "i"]) @
[str " =", Pretty.brk 1] @
separate (Pretty.brk 1) (str (gen_name ^ "'") :: gs @
[str "i", str "i"]))]) @
mk_gen_of_def gr "and " xs
end
in
(module', (add_edge_acyclic (node_id, dep) gr
handle Graph.CYCLES _ => gr) handle Graph.UNDEF _ =>
let
val gr1 = add_edge (node_id, dep)
(new_node (node_id, (NONE, "", "")) gr);
val (dtdef, gr2) = mk_dtdef "datatype " descr' gr1 ;
in
map_node node_id (K (NONE, module',
string_of (Pretty.blk (0, separate Pretty.fbrk dtdef @
[str ";"])) ^ "\n\n" ^
(if member (op =) (!mode) "term_of" then
string_of (Pretty.blk (0, separate Pretty.fbrk
(mk_term_of_def gr2 "fun " descr') @ [str ";"])) ^ "\n\n"
else "") ^
(if member (op =) (!mode) "test" then
string_of (Pretty.blk (0, separate Pretty.fbrk
(mk_gen_of_def gr2 "fun " descr') @ [str ";"])) ^ "\n\n"
else ""))) gr2
end)
end;
(* case expressions *)
fun pretty_case thy defs dep module brack constrs (c as Const (_, T)) ts gr =
let val i = length constrs
in if length ts <= i then
invoke_codegen thy defs dep module brack (eta_expand c ts (i+1)) gr
else
let
val ts1 = take i ts;
val t :: ts2 = drop i ts;
val names = List.foldr OldTerm.add_term_names
(map (fst o fst o dest_Var) (List.foldr OldTerm.add_term_vars [] ts1)) ts1;
val (Ts, dT) = split_last (take (i+1) (fst (strip_type T)));
fun pcase [] [] [] gr = ([], gr)
| pcase ((cname, cargs)::cs) (t::ts) (U::Us) gr =
let
val j = length cargs;
val xs = Name.variant_list names (replicate j "x");
val Us' = take j (fst (strip_type U));
val frees = map2 (curry Free) xs Us';
val (cp, gr0) = invoke_codegen thy defs dep module false
(list_comb (Const (cname, Us' ---> dT), frees)) gr;
val t' = Envir.beta_norm (list_comb (t, frees));
val (p, gr1) = invoke_codegen thy defs dep module false t' gr0;
val (ps, gr2) = pcase cs ts Us gr1;
in
([Pretty.block [cp, str " =>", Pretty.brk 1, p]] :: ps, gr2)
end;
val (ps1, gr1) = pcase constrs ts1 Ts gr ;
val ps = flat (separate [Pretty.brk 1, str "| "] ps1);
val (p, gr2) = invoke_codegen thy defs dep module false t gr1;
val (ps2, gr3) = fold_map (invoke_codegen thy defs dep module true) ts2 gr2;
in ((if not (null ts2) andalso brack then parens else I)
(Pretty.block (separate (Pretty.brk 1)
(Pretty.block ([str "(case ", p, str " of",
Pretty.brk 1] @ ps @ [str ")"]) :: ps2))), gr3)
end
end;
(* constructors *)
fun pretty_constr thy defs dep module brack args (c as Const (s, T)) ts gr =
let val i = length args
in if i > 1 andalso length ts < i then
invoke_codegen thy defs dep module brack (eta_expand c ts i) gr
else
let
val id = mk_qual_id module (get_const_id gr s);
val (ps, gr') = fold_map
(invoke_codegen thy defs dep module (i = 1)) ts gr;
in (case args of
_ :: _ :: _ => (if brack then parens else I)
(Pretty.block [str id, Pretty.brk 1, mk_tuple ps])
| _ => (mk_app brack (str id) ps), gr')
end
end;
(* code generators for terms and types *)
fun datatype_codegen thy defs dep module brack t gr = (case strip_comb t of
(c as Const (s, T), ts) =>
(case Datatype_Data.info_of_case thy s of
SOME {index, descr, ...} =>
if is_some (get_assoc_code thy (s, T)) then NONE else
SOME (pretty_case thy defs dep module brack
(#3 (the (AList.lookup op = descr index))) c ts gr )
| NONE => case (Datatype_Data.info_of_constr thy (s, T), strip_type T) of
(SOME {index, descr, ...}, (_, U as Type (tyname, _))) =>
if is_some (get_assoc_code thy (s, T)) then NONE else
let
val SOME (tyname', _, constrs) = AList.lookup op = descr index;
val SOME args = AList.lookup op = constrs s
in
if tyname <> tyname' then NONE
else SOME (pretty_constr thy defs
dep module brack args c ts (snd (invoke_tycodegen thy defs dep module false U gr)))
end
| _ => NONE)
| _ => NONE);
fun datatype_tycodegen thy defs dep module brack (Type (s, Ts)) gr =
(case Datatype_Data.get_info thy s of
NONE => NONE
| SOME {descr, sorts, ...} =>
if is_some (get_assoc_type thy s) then NONE else
let
val (ps, gr') = fold_map
(invoke_tycodegen thy defs dep module false) Ts gr;
val (module', gr'') = add_dt_defs thy defs dep module descr sorts gr' ;
val (tyid, gr''') = mk_type_id module' s gr''
in SOME (Pretty.block ((if null Ts then [] else
[mk_tuple ps, str " "]) @
[str (mk_qual_id module tyid)]), gr''')
end)
| datatype_tycodegen _ _ _ _ _ _ _ = NONE;
(** theory setup **)
val setup =
Datatype_Data.interpretation add_all_code
#> add_codegen "datatype" datatype_codegen
#> add_tycodegen "datatype" datatype_tycodegen;
end;