(* Title: HOL/Tools/recdef_package.ML
ID: $Id$
Author: Markus Wenzel, TU Muenchen
Wrapper module for Konrad Slind's TFL package.
*)
signature RECDEF_PACKAGE =
sig
val quiet_mode: bool ref
val print_recdefs: theory -> unit
val get_recdef: theory -> string
-> {simps: thm list, rules: thm list list, induct: thm, tcs: term list} option
val simp_add_global: theory attribute
val simp_del_global: theory attribute
val cong_add_global: theory attribute
val cong_del_global: theory attribute
val wf_add_global: theory attribute
val wf_del_global: theory attribute
val simp_add_local: Proof.context attribute
val simp_del_local: Proof.context attribute
val cong_add_local: Proof.context attribute
val cong_del_local: Proof.context attribute
val wf_add_local: Proof.context attribute
val wf_del_local: Proof.context attribute
val add_recdef: bool -> xstring -> string -> ((bstring * string) * Attrib.src list) list ->
Attrib.src option -> theory -> theory
* {simps: thm list, rules: thm list list, induct: thm, tcs: term list}
val add_recdef_i: bool -> xstring -> term -> ((bstring * term) * theory attribute list) list ->
theory -> theory * {simps: thm list, rules: thm list list, induct: thm, tcs: term list}
val defer_recdef: xstring -> string list -> (thmref * Attrib.src list) list
-> theory -> theory * {induct_rules: thm}
val defer_recdef_i: xstring -> term list -> (thm list * theory attribute list) list
-> theory -> theory * {induct_rules: thm}
val recdef_tc: bstring * Attrib.src list -> xstring -> int option -> theory -> Proof.state
val recdef_tc_i: bstring * theory attribute list -> string -> int option
-> theory -> Proof.state
val setup: (theory -> theory) list
end;
structure RecdefPackage: RECDEF_PACKAGE =
struct
val quiet_mode = Tfl.quiet_mode;
val message = Tfl.message;
(** recdef hints **)
(* type hints *)
type hints = {simps: thm list, congs: (string * thm) list, wfs: thm list};
fun mk_hints (simps, congs, wfs) = {simps = simps, congs = congs, wfs = wfs}: hints;
fun map_hints f ({simps, congs, wfs}: hints) = mk_hints (f (simps, congs, wfs));
fun map_simps f = map_hints (fn (simps, congs, wfs) => (f simps, congs, wfs));
fun map_congs f = map_hints (fn (simps, congs, wfs) => (simps, f congs, wfs));
fun map_wfs f = map_hints (fn (simps, congs, wfs) => (simps, congs, f wfs));
fun pretty_hints ({simps, congs, wfs}: hints) =
[Pretty.big_list "recdef simp hints:" (map Display.pretty_thm simps),
Pretty.big_list "recdef cong hints:" (map Display.pretty_thm (map #2 congs)),
Pretty.big_list "recdef wf hints:" (map Display.pretty_thm wfs)];
(* congruence rules *)
local
val cong_head =
fst o Term.dest_Const o Term.head_of o fst o Logic.dest_equals o Thm.concl_of;
fun prep_cong raw_thm =
let val thm = safe_mk_meta_eq raw_thm in (cong_head thm, thm) end;
in
fun add_cong raw_thm congs =
let val (c, thm) = prep_cong raw_thm
in overwrite_warn (congs, (c, thm)) ("Overwriting recdef congruence rule for " ^ quote c) end;
fun del_cong raw_thm congs =
let
val (c, thm) = prep_cong raw_thm;
val (del, rest) = Library.partition (Library.equal c o fst) congs;
in if null del then (warning ("No recdef congruence rule for " ^ quote c); congs) else rest end;
val add_congs = foldr (uncurry add_cong);
end;
(** global and local recdef data **)
(* theory data *)
type recdef_info = {simps: thm list, rules: thm list list, induct: thm, tcs: term list};
structure GlobalRecdefData = TheoryDataFun
(struct
val name = "HOL/recdef";
type T = recdef_info Symtab.table * hints;
val empty = (Symtab.empty, mk_hints ([], [], [])): T;
val copy = I;
val extend = I;
fun merge _
((tab1, {simps = simps1, congs = congs1, wfs = wfs1}),
(tab2, {simps = simps2, congs = congs2, wfs = wfs2})) : T =
(Symtab.merge (K true) (tab1, tab2),
mk_hints (Drule.merge_rules (simps1, simps2),
Library.merge_alists congs1 congs2,
Drule.merge_rules (wfs1, wfs2)));
fun print thy (tab, hints) =
(Pretty.strs ("recdefs:" :: map #1 (NameSpace.extern_table (Sign.const_space thy, tab))) ::
pretty_hints hints) |> Pretty.chunks |> Pretty.writeln;
end);
val print_recdefs = GlobalRecdefData.print;
val get_recdef = Symtab.lookup o #1 o GlobalRecdefData.get;
fun put_recdef name info thy =
let
val (tab, hints) = GlobalRecdefData.get thy;
val tab' = Symtab.update_new (name, info) tab
handle Symtab.DUP _ => error ("Duplicate recursive function definition " ^ quote name);
in GlobalRecdefData.put (tab', hints) thy end;
val get_global_hints = #2 o GlobalRecdefData.get;
val map_global_hints = GlobalRecdefData.map o apsnd;
(* proof data *)
structure LocalRecdefData = ProofDataFun
(struct
val name = "HOL/recdef";
type T = hints;
val init = get_global_hints;
fun print _ hints = pretty_hints hints |> Pretty.chunks |> Pretty.writeln;
end);
val get_local_hints = LocalRecdefData.get;
val map_local_hints = LocalRecdefData.map;
(* attributes *)
local
fun global_local f g =
(fn (thy, thm) => (map_global_hints (f (g thm)) thy, thm),
fn (ctxt, thm) => (map_local_hints (f (g thm)) ctxt, thm));
fun mk_attr (add1, add2) (del1, del2) =
(Attrib.add_del_args add1 del1, Attrib.add_del_args add2 del2);
in
val (simp_add_global, simp_add_local) = global_local map_simps Drule.add_rule;
val (simp_del_global, simp_del_local) = global_local map_simps Drule.del_rule;
val (cong_add_global, cong_add_local) = global_local map_congs add_cong;
val (cong_del_global, cong_del_local) = global_local map_congs del_cong;
val (wf_add_global, wf_add_local) = global_local map_wfs Drule.add_rule;
val (wf_del_global, wf_del_local) = global_local map_wfs Drule.del_rule;
val simp_attr = mk_attr (simp_add_global, simp_add_local) (simp_del_global, simp_del_local);
val cong_attr = mk_attr (cong_add_global, cong_add_local) (cong_del_global, cong_del_local);
val wf_attr = mk_attr (wf_add_global, wf_add_local) (wf_del_global, wf_del_local);
end;
(* modifiers *)
val recdef_simpN = "recdef_simp";
val recdef_congN = "recdef_cong";
val recdef_wfN = "recdef_wf";
val recdef_modifiers =
[Args.$$$ recdef_simpN -- Args.colon >> K ((I, simp_add_local): Method.modifier),
Args.$$$ recdef_simpN -- Args.add -- Args.colon >> K (I, simp_add_local),
Args.$$$ recdef_simpN -- Args.del -- Args.colon >> K (I, simp_del_local),
Args.$$$ recdef_congN -- Args.colon >> K (I, cong_add_local),
Args.$$$ recdef_congN -- Args.add -- Args.colon >> K (I, cong_add_local),
Args.$$$ recdef_congN -- Args.del -- Args.colon >> K (I, cong_del_local),
Args.$$$ recdef_wfN -- Args.colon >> K (I, wf_add_local),
Args.$$$ recdef_wfN -- Args.add -- Args.colon >> K (I, wf_add_local),
Args.$$$ recdef_wfN -- Args.del -- Args.colon >> K (I, wf_del_local)] @
Clasimp.clasimp_modifiers;
(** prepare_hints(_i) **)
fun prepare_hints thy opt_src =
let
val ctxt0 = ProofContext.init thy;
val ctxt =
(case opt_src of
NONE => ctxt0
| SOME src => Method.only_sectioned_args recdef_modifiers I src ctxt0);
val {simps, congs, wfs} = get_local_hints ctxt;
val cs = local_claset_of ctxt;
val ss = local_simpset_of ctxt addsimps simps;
in (cs, ss, map #2 congs, wfs) end;
fun prepare_hints_i thy () =
let
val ctxt0 = ProofContext.init thy;
val {simps, congs, wfs} = get_global_hints thy;
in (local_claset_of ctxt0, local_simpset_of ctxt0 addsimps simps, map #2 congs, wfs) end;
(** add_recdef(_i) **)
fun requires_recdef thy = Theory.requires thy "Recdef" "recursive functions";
fun gen_add_recdef tfl_fn prep_att prep_hints not_permissive raw_name R eq_srcs hints thy =
let
val _ = requires_recdef thy;
val name = Sign.intern_const thy raw_name;
val bname = Sign.base_name name;
val _ = message ("Defining recursive function " ^ quote name ^ " ...");
val ((eq_names, eqs), raw_eq_atts) = apfst split_list (split_list eq_srcs);
val eq_atts = map (map (prep_att thy)) raw_eq_atts;
val (cs, ss, congs, wfs) = prep_hints thy hints;
(*We must remove imp_cong to prevent looping when the induction rule
is simplified. Many induction rules have nested implications that would
give rise to looping conditional rewriting.*)
val (thy, {rules = rules_idx, induct, tcs}) =
tfl_fn not_permissive thy cs (ss delcongs [imp_cong])
congs wfs name R eqs;
val rules = map (map #1) (Library.partition_eq (Library.eq_snd (op =)) rules_idx);
val simp_att = if null tcs then
[Simplifier.simp_add_global, RecfunCodegen.add NONE] else [];
val ((simps' :: rules', [induct']), thy) =
thy
|> Theory.add_path bname
|> PureThy.add_thmss ((("simps", List.concat rules), simp_att) :: ((eq_names ~~ rules) ~~ eq_atts))
||>> PureThy.add_thms [(("induct", induct), [])];
val result = {simps = simps', rules = rules', induct = induct', tcs = tcs};
val thy =
thy
|> put_recdef name result
|> Theory.parent_path;
in (thy, result) end;
val add_recdef = gen_add_recdef Tfl.define Attrib.global_attribute prepare_hints;
fun add_recdef_i x y z w = gen_add_recdef Tfl.define_i (K I) prepare_hints_i x y z w ();
(** defer_recdef(_i) **)
fun gen_defer_recdef tfl_fn app_thms raw_name eqs raw_congs thy =
let
val name = Sign.intern_const thy raw_name;
val bname = Sign.base_name name;
val _ = requires_recdef thy;
val _ = message ("Deferred recursive function " ^ quote name ^ " ...");
val (congs, thy1) = thy |> app_thms raw_congs;
val (thy2, induct_rules) = tfl_fn thy1 congs name eqs;
val ([induct_rules'], thy3) =
thy2
|> Theory.add_path bname
|> PureThy.add_thms [(("induct_rules", induct_rules), [])]
||> Theory.parent_path;
in (thy3, {induct_rules = induct_rules'}) end;
val defer_recdef = gen_defer_recdef Tfl.defer IsarThy.apply_theorems;
val defer_recdef_i = gen_defer_recdef Tfl.defer_i IsarThy.apply_theorems_i;
(** recdef_tc(_i) **)
fun gen_recdef_tc prep_att prep_name (bname, raw_atts) raw_name opt_i thy =
let
val name = prep_name thy raw_name;
val atts = map (prep_att thy) raw_atts;
val tcs =
(case get_recdef thy name of
NONE => error ("No recdef definition of constant: " ^ quote name)
| SOME {tcs, ...} => tcs);
val i = getOpt (opt_i, 1);
val tc = List.nth (tcs, i - 1) handle Subscript =>
error ("No termination condition #" ^ string_of_int i ^
" in recdef definition of " ^ quote name);
in IsarThy.theorem_i Drule.internalK (bname, atts) (HOLogic.mk_Trueprop tc, ([], [])) thy end;
val recdef_tc = gen_recdef_tc Attrib.global_attribute Sign.intern_const;
val recdef_tc_i = gen_recdef_tc (K I) (K I);
(** package setup **)
(* setup theory *)
val setup =
[GlobalRecdefData.init, LocalRecdefData.init,
Attrib.add_attributes
[(recdef_simpN, simp_attr, "declaration of recdef simp rule"),
(recdef_congN, cong_attr, "declaration of recdef cong rule"),
(recdef_wfN, wf_attr, "declaration of recdef wf rule")]];
(* outer syntax *)
local structure P = OuterParse and K = OuterKeyword in
val hints =
P.$$$ "(" |-- P.!!! (P.position (P.$$$ "hints" -- P.arguments) --| P.$$$ ")") >> Args.src;
val recdef_decl =
Scan.optional (P.$$$ "(" -- P.!!! (P.$$$ "permissive" -- P.$$$ ")") >> K false) true --
P.name -- P.term -- Scan.repeat1 (P.opt_thm_name ":" -- P.prop) -- Scan.option hints
>> (fn ((((p, f), R), eqs), src) => #1 o add_recdef p f R (map P.triple_swap eqs) src);
val recdefP =
OuterSyntax.command "recdef" "define general recursive functions (TFL)" K.thy_decl
(recdef_decl >> Toplevel.theory);
val defer_recdef_decl =
P.name -- Scan.repeat1 P.prop --
Scan.optional (P.$$$ "(" |-- P.$$$ "congs" |-- P.!!! (P.xthms1 --| P.$$$ ")")) []
>> (fn ((f, eqs), congs) => #1 o defer_recdef f eqs congs);
val defer_recdefP =
OuterSyntax.command "defer_recdef" "defer general recursive functions (TFL)" K.thy_decl
(defer_recdef_decl >> Toplevel.theory);
val recdef_tcP =
OuterSyntax.command "recdef_tc" "recommence proof of termination condition (TFL)" K.thy_goal
(P.opt_thm_name ":" -- P.xname -- Scan.option (P.$$$ "(" |-- P.nat --| P.$$$ ")")
>> (fn ((thm_name, name), i) =>
Toplevel.print o Toplevel.theory_to_proof (recdef_tc thm_name name i)));
val _ = OuterSyntax.add_keywords ["permissive", "congs", "hints"];
val _ = OuterSyntax.add_parsers [recdefP, defer_recdefP, recdef_tcP];
end;
end;