--- a/src/HOL/Tools/old_primrec.ML Tue Sep 28 15:34:47 2010 +0200
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,326 +0,0 @@
-(* Title: HOL/Tools/old_primrec.ML
- Author: Norbert Voelker, FernUni Hagen
- Author: Stefan Berghofer, TU Muenchen
-
-Package for defining functions on datatypes by primitive recursion.
-*)
-
-signature OLD_PRIMREC =
-sig
- val unify_consts: theory -> term list -> term list -> term list * term list
- val add_primrec: string -> ((bstring * string) * Attrib.src list) list
- -> theory -> thm list * theory
- val add_primrec_unchecked: string -> ((bstring * string) * Attrib.src list) list
- -> theory -> thm list * theory
- val add_primrec_i: string -> ((bstring * term) * attribute list) list
- -> theory -> thm list * theory
- val add_primrec_unchecked_i: string -> ((bstring * term) * attribute list) list
- -> theory -> thm list * theory
-end;
-
-structure OldPrimrec : OLD_PRIMREC =
-struct
-
-open Datatype_Aux;
-
-exception RecError of string;
-
-fun primrec_err s = error ("Primrec definition error:\n" ^ s);
-fun primrec_eq_err thy s eq =
- primrec_err (s ^ "\nin\n" ^ quote (Syntax.string_of_term_global thy eq));
-
-
-(*the following code ensures that each recursive set always has the
- same type in all introduction rules*)
-fun unify_consts thy cs intr_ts =
- (let
- fun varify t (i, ts) =
- let val t' = map_types (Logic.incr_tvar (i + 1)) (snd (Type.varify_global [] t))
- in (maxidx_of_term t', t'::ts) end;
- val (i, cs') = fold_rev varify cs (~1, []);
- val (i', intr_ts') = fold_rev varify intr_ts (i, []);
- val rec_consts = fold Term.add_consts cs' [];
- val intr_consts = fold Term.add_consts intr_ts' [];
- fun unify (cname, cT) =
- let val consts = map snd (filter (fn (c, _) => c = cname) intr_consts)
- in fold (Sign.typ_unify thy) ((replicate (length consts) cT) ~~ consts) end;
- val (env, _) = fold unify rec_consts (Vartab.empty, i');
- val subst = Type.legacy_freeze o map_types (Envir.norm_type env)
-
- in (map subst cs', map subst intr_ts')
- end) handle Type.TUNIFY =>
- (warning "Occurrences of recursive constant have non-unifiable types"; (cs, intr_ts));
-
-
-(* preprocessing of equations *)
-
-fun process_eqn thy eq rec_fns =
- let
- val (lhs, rhs) =
- if null (Term.add_vars eq []) then
- HOLogic.dest_eq (HOLogic.dest_Trueprop eq)
- handle TERM _ => raise RecError "not a proper equation"
- else raise RecError "illegal schematic variable(s)";
-
- val (recfun, args) = strip_comb lhs;
- val fnameT = dest_Const recfun handle TERM _ =>
- raise RecError "function is not declared as constant in theory";
-
- val (ls', rest) = take_prefix is_Free args;
- val (middle, rs') = take_suffix is_Free rest;
- val rpos = length ls';
-
- val (constr, cargs') = if null middle then raise RecError "constructor missing"
- else strip_comb (hd middle);
- val (cname, T) = dest_Const constr
- handle TERM _ => raise RecError "ill-formed constructor";
- val (tname, _) = dest_Type (body_type T) handle TYPE _ =>
- raise RecError "cannot determine datatype associated with function"
-
- val (ls, cargs, rs) =
- (map dest_Free ls', map dest_Free cargs', map dest_Free rs')
- handle TERM _ => raise RecError "illegal argument in pattern";
- val lfrees = ls @ rs @ cargs;
-
- fun check_vars _ [] = ()
- | check_vars s vars = raise RecError (s ^ commas_quote (map fst vars))
- in
- if length middle > 1 then
- raise RecError "more than one non-variable in pattern"
- else
- (check_vars "repeated variable names in pattern: " (duplicates (op =) lfrees);
- check_vars "extra variables on rhs: "
- (subtract (op =) lfrees (map dest_Free (OldTerm.term_frees rhs)));
- case AList.lookup (op =) rec_fns fnameT of
- NONE =>
- (fnameT, (tname, rpos, [(cname, (ls, cargs, rs, rhs, eq))]))::rec_fns
- | SOME (_, rpos', eqns) =>
- if AList.defined (op =) eqns cname then
- raise RecError "constructor already occurred as pattern"
- else if rpos <> rpos' then
- raise RecError "position of recursive argument inconsistent"
- else
- AList.update (op =) (fnameT, (tname, rpos, (cname, (ls, cargs, rs, rhs, eq))::eqns))
- rec_fns)
- end
- handle RecError s => primrec_eq_err thy s eq;
-
-fun process_fun thy descr rec_eqns (i, fnameT as (fname, _)) (fnameTs, fnss) =
- let
- val (_, (tname, _, constrs)) = List.nth (descr, i);
-
- (* substitute "fname ls x rs" by "y ls rs" for (x, (_, y)) in subs *)
-
- fun subst [] t fs = (t, fs)
- | subst subs (Abs (a, T, t)) fs =
- fs
- |> subst subs t
- |-> (fn t' => pair (Abs (a, T, t')))
- | subst subs (t as (_ $ _)) fs =
- let
- val (f, ts) = strip_comb t;
- in
- if is_Const f andalso member (op =) (map fst rec_eqns) (dest_Const f) then
- let
- val fnameT' as (fname', _) = dest_Const f;
- val (_, rpos, _) = the (AList.lookup (op =) rec_eqns fnameT');
- val ls = take rpos ts;
- val rest = drop rpos ts;
- val (x', rs) = (hd rest, tl rest)
- handle Empty => raise RecError ("not enough arguments\
- \ in recursive application\nof function " ^ quote fname' ^ " on rhs");
- val (x, xs) = strip_comb x'
- in case AList.lookup (op =) subs x
- of NONE =>
- fs
- |> fold_map (subst subs) ts
- |-> (fn ts' => pair (list_comb (f, ts')))
- | SOME (i', y) =>
- fs
- |> fold_map (subst subs) (xs @ ls @ rs)
- ||> process_fun thy descr rec_eqns (i', fnameT')
- |-> (fn ts' => pair (list_comb (y, ts')))
- end
- else
- fs
- |> fold_map (subst subs) (f :: ts)
- |-> (fn (f'::ts') => pair (list_comb (f', ts')))
- end
- | subst _ t fs = (t, fs);
-
- (* translate rec equations into function arguments suitable for rec comb *)
-
- fun trans eqns (cname, cargs) (fnameTs', fnss', fns) =
- (case AList.lookup (op =) eqns cname of
- NONE => (warning ("No equation for constructor " ^ quote cname ^
- "\nin definition of function " ^ quote fname);
- (fnameTs', fnss', (Const ("HOL.undefined", dummyT))::fns))
- | SOME (ls, cargs', rs, rhs, eq) =>
- let
- val recs = filter (is_rec_type o snd) (cargs' ~~ cargs);
- val rargs = map fst recs;
- val subs = map (rpair dummyT o fst)
- (rev (Term.rename_wrt_term rhs rargs));
- val (rhs', (fnameTs'', fnss'')) =
- (subst (map (fn ((x, y), z) =>
- (Free x, (body_index y, Free z)))
- (recs ~~ subs)) rhs (fnameTs', fnss'))
- handle RecError s => primrec_eq_err thy s eq
- in (fnameTs'', fnss'',
- (list_abs_free (cargs' @ subs @ ls @ rs, rhs'))::fns)
- end)
-
- in (case AList.lookup (op =) fnameTs i of
- NONE =>
- if exists (equal fnameT o snd) fnameTs then
- raise RecError ("inconsistent functions for datatype " ^ quote tname)
- else
- let
- val (_, _, eqns) = the (AList.lookup (op =) rec_eqns fnameT);
- val (fnameTs', fnss', fns) = fold_rev (trans eqns) constrs
- ((i, fnameT)::fnameTs, fnss, [])
- in
- (fnameTs', (i, (fname, #1 (snd (hd eqns)), fns))::fnss')
- end
- | SOME fnameT' =>
- if fnameT = fnameT' then (fnameTs, fnss)
- else raise RecError ("inconsistent functions for datatype " ^ quote tname))
- end;
-
-
-(* prepare functions needed for definitions *)
-
-fun get_fns fns ((i : int, (tname, _, constrs)), rec_name) (fs, defs) =
- case AList.lookup (op =) fns i of
- NONE =>
- let
- val dummy_fns = map (fn (_, cargs) => Const ("HOL.undefined",
- replicate (length cargs + length (filter is_rec_type cargs))
- dummyT ---> HOLogic.unitT)) constrs;
- val _ = warning ("No function definition for datatype " ^ quote tname)
- in
- (dummy_fns @ fs, defs)
- end
- | SOME (fname, ls, fs') => (fs' @ fs, (fname, ls, rec_name, tname) :: defs);
-
-
-(* make definition *)
-
-fun make_def thy fs (fname, ls, rec_name, tname) =
- let
- val rhs = fold_rev (fn T => fn t => Abs ("", T, t))
- ((map snd ls) @ [dummyT])
- (list_comb (Const (rec_name, dummyT),
- fs @ map Bound (0 ::(length ls downto 1))))
- val def_name = Long_Name.base_name fname ^ "_" ^ Long_Name.base_name tname ^ "_def";
- val def_prop =
- singleton (Syntax.check_terms (ProofContext.init_global thy))
- (Logic.mk_equals (Const (fname, dummyT), rhs));
- in (def_name, def_prop) end;
-
-
-(* find datatypes which contain all datatypes in tnames' *)
-
-fun find_dts (dt_info : info Symtab.table) _ [] = []
- | find_dts dt_info tnames' (tname::tnames) =
- (case Symtab.lookup dt_info tname of
- NONE => primrec_err (quote tname ^ " is not a datatype")
- | SOME dt =>
- if subset (op =) (tnames', map (#1 o snd) (#descr dt)) then
- (tname, dt)::(find_dts dt_info tnames' tnames)
- else find_dts dt_info tnames' tnames);
-
-fun prepare_induct ({descr, induct, ...}: info) rec_eqns =
- let
- fun constrs_of (_, (_, _, cs)) =
- map (fn (cname:string, (_, cargs, _, _, _)) => (cname, map fst cargs)) cs;
- val params_of = these o AList.lookup (op =) (maps constrs_of rec_eqns);
- in
- induct
- |> Rule_Cases.rename_params (map params_of (maps (map #1 o #3 o #2) descr))
- |> Rule_Cases.save induct
- end;
-
-local
-
-fun gen_primrec_i note def alt_name eqns_atts thy =
- let
- val (eqns, atts) = split_list eqns_atts;
- val dt_info = Datatype_Data.get_all thy;
- val rec_eqns = fold_rev (process_eqn thy o snd) eqns [] ;
- val tnames = distinct (op =) (map (#1 o snd) rec_eqns);
- val dts = find_dts dt_info tnames tnames;
- val main_fns =
- map (fn (tname, {index, ...}) =>
- (index,
- (fst o the o find_first (fn f => (#1 o snd) f = tname)) rec_eqns))
- dts;
- val {descr, rec_names, rec_rewrites, ...} =
- if null dts then
- primrec_err ("datatypes " ^ commas_quote tnames ^ "\nare not mutually recursive")
- else snd (hd dts);
- val (fnameTs, fnss) =
- fold_rev (process_fun thy descr rec_eqns) main_fns ([], []);
- val (fs, defs) = fold_rev (get_fns fnss) (descr ~~ rec_names) ([], []);
- val defs' = map (make_def thy fs) defs;
- val nameTs1 = map snd fnameTs;
- val nameTs2 = map fst rec_eqns;
- val _ = if eq_set (op =) (nameTs1, nameTs2) then ()
- else primrec_err ("functions " ^ commas_quote (map fst nameTs2) ^
- "\nare not mutually recursive");
- val primrec_name =
- if alt_name = "" then (space_implode "_" (map (Long_Name.base_name o #1) defs)) else alt_name;
- val (defs_thms', thy') =
- thy
- |> Sign.add_path primrec_name
- |> fold_map def (map (fn (name, t) => ((name, []), t)) defs');
- val rewrites = (map mk_meta_eq rec_rewrites) @ map snd defs_thms';
- val simps = map (fn (_, t) => Goal.prove_global thy' [] [] t
- (fn _ => EVERY [rewrite_goals_tac rewrites, rtac refl 1])) eqns;
- val (simps', thy'') =
- thy'
- |> fold_map note ((map fst eqns ~~ atts) ~~ map single simps);
- val simps'' = maps snd simps';
- val lhss = map (Logic.varify_global o fst o Logic.dest_equals o snd) defs';
- in
- thy''
- |> note (("simps",
- [Simplifier.simp_add, Nitpick_Simps.add, Code.add_default_eqn_attribute]), simps'')
- |> snd
- |> Spec_Rules.add_global Spec_Rules.Equational (lhss, simps)
- |> note (("induct", []), [prepare_induct (#2 (hd dts)) rec_eqns])
- |> snd
- |> Sign.parent_path
- |> pair simps''
- end;
-
-fun gen_primrec note def alt_name eqns thy =
- let
- val ((names, strings), srcss) = apfst split_list (split_list eqns);
- val atts = map (map (Attrib.attribute thy)) srcss;
- val eqn_ts = map (fn s => Syntax.read_prop_global thy s
- handle ERROR msg => cat_error msg ("The error(s) above occurred for " ^ s)) strings;
- val rec_ts = map (fn eq => head_of (fst (HOLogic.dest_eq (HOLogic.dest_Trueprop eq)))
- handle TERM _ => primrec_eq_err thy "not a proper equation" eq) eqn_ts;
- val (_, eqn_ts') = unify_consts thy rec_ts eqn_ts
- in
- gen_primrec_i note def alt_name (names ~~ eqn_ts' ~~ atts) thy
- end;
-
-fun thy_note ((name, atts), thms) =
- Global_Theory.add_thmss [((Binding.name name, thms), atts)] #-> (fn [thms] => pair (name, thms));
-fun thy_def false ((name, atts), t) =
- Global_Theory.add_defs false [((Binding.name name, t), atts)] #-> (fn [thm] => pair (name, thm))
- | thy_def true ((name, atts), t) =
- Global_Theory.add_defs_unchecked false [((Binding.name name, t), atts)] #-> (fn [thm] => pair (name, thm));
-
-in
-
-val add_primrec = gen_primrec thy_note (thy_def false);
-val add_primrec_unchecked = gen_primrec thy_note (thy_def true);
-val add_primrec_i = gen_primrec_i thy_note (thy_def false);
-val add_primrec_unchecked_i = gen_primrec_i thy_note (thy_def true);
-
-end;
-
-end;