krauss@19564: (*  Title:      HOL/Tools/function_package/fundef_package.ML
krauss@19564:     ID:         $Id$
krauss@19564:     Author:     Alexander Krauss, TU Muenchen
krauss@19564: 
krauss@19564: A package for general recursive function definitions. 
krauss@19564: Isar commands.
krauss@19564: 
krauss@19564: *)
krauss@19564: 
krauss@19564: signature FUNDEF_PACKAGE = 
krauss@19564: sig
krauss@19770:     val add_fundef : ((bstring * Attrib.src list) * string) list list -> theory -> Proof.state (* Need an _i variant *)
krauss@19564: 
krauss@19564:     val cong_add: attribute
krauss@19564:     val cong_del: attribute
krauss@19564: 							 
krauss@19564:     val setup : theory -> theory
krauss@19770:     val get_congs : theory -> thm list
krauss@19564: end
krauss@19564: 
krauss@19564: 
krauss@19564: structure FundefPackage : FUNDEF_PACKAGE =
krauss@19564: struct
krauss@19564: 
krauss@19564: open FundefCommon
krauss@19564: 
krauss@19564: val True_implies = thm "True_implies"
krauss@19564: 
krauss@19564: 
krauss@19770: fun add_simps label moreatts (MutualPart {f_name, ...}, psimps) (names, attss) thy =
krauss@19770:     let 
krauss@19770:       val thy = thy |> Theory.add_path f_name 
krauss@19770:                 
krauss@19770:       val thy = thy |> Theory.add_path label
krauss@19770:       val spsimps = map standard psimps
krauss@19770:       val add_list = (names ~~ spsimps) ~~ attss
krauss@19770:       val (_, thy) = PureThy.add_thms add_list thy
krauss@19770:       val thy = thy |> Theory.parent_path
krauss@19770:                 
krauss@19770:       val (_, thy) = PureThy.add_thmss [((label, spsimps), Simplifier.simp_add :: moreatts)] thy
krauss@19770:       val thy = thy |> Theory.parent_path
krauss@19770:     in
krauss@19770:       thy
krauss@19770:     end
krauss@19770:     
krauss@19770: 
krauss@19770: 
krauss@19770: 
krauss@19770: 
krauss@19770: 
krauss@19611: fun fundef_afterqed congs curry_info name data names atts thmss thy =
krauss@19564:     let
krauss@19564: 	val (complete_thm :: compat_thms) = map hd thmss
krauss@19770: 	val fundef_data = FundefMutual.mk_partial_rules_mutual thy congs curry_info data (freezeT complete_thm) (map freezeT compat_thms)
krauss@19770: 	val FundefMResult {psimps, subset_pinducts, simple_pinducts, termination, domintros, ...} = fundef_data
krauss@19770:         val Mutual {parts, ...} = curry_info
krauss@19564: 
krauss@19583: 	val Prep {names = Names {acc_R=accR, ...}, ...} = data
krauss@19583: 	val dom_abbrev = Logic.mk_equals (Free (name ^ "_dom", fastype_of accR), accR)
krauss@19583: 	val (_, thy) = LocalTheory.mapping NONE (Specification.abbreviation_i ("", false) [(NONE, dom_abbrev)]) thy
krauss@19564: 
krauss@19770:         val thy = fold2 (add_simps "psimps" []) (parts ~~ psimps) (names ~~ atts) thy
krauss@19564: 
krauss@19770: 	val thy = thy |> Theory.add_path name
krauss@19770: 	val (_, thy) = PureThy.add_thms [(("cases", complete_thm), [RuleCases.case_names (flat names)])] thy
krauss@19770: 	val (_, thy) = PureThy.add_thmss [(("domintros", domintros), [])] thy
krauss@19770: 	val (_, thy) = PureThy.add_thms [(("termination", termination), [])] thy
krauss@19770: 	val (_,thy) = PureThy.add_thmss [(("pinduct", map standard simple_pinducts), [RuleCases.case_names (flat names), InductAttrib.induct_set ""])] thy
krauss@19564: 	val thy = thy |> Theory.parent_path
krauss@19564:     in
krauss@19770: 	add_fundef_data name (fundef_data, curry_info, names, atts) thy
krauss@19564:     end
krauss@19564: 
krauss@19770: fun gen_add_fundef prep_att eqns_attss thy =
krauss@19564:     let
krauss@19770: 	fun split eqns_atts =
krauss@19770: 	    let 
krauss@19770: 		val (natts, eqns) = split_list eqns_atts
krauss@19770: 		val (names, raw_atts) = split_list natts
krauss@19770: 		val atts = map (map (prep_att thy)) raw_atts
krauss@19770: 	    in
krauss@19770: 		((names, atts), eqns)
krauss@19770: 	    end
krauss@19611: 
krauss@19770: 
krauss@19770: 	val (natts, eqns) = split_list (map split_list eqns_attss)
krauss@19770: 	val (names, raw_atts) = split_list (map split_list natts)
krauss@19770: 
krauss@19770: 	val atts = map (map (map (prep_att thy))) raw_atts
krauss@19564: 
krauss@19564: 	val congs = get_fundef_congs (Context.Theory thy)
krauss@19564: 
krauss@19770: 	val t_eqns = map (map (Sign.read_prop thy)) eqns
krauss@19770: 			 |> map (map (term_of o cterm_of thy)) (* HACK to prevent strange things from happening with abbreviations *)
krauss@19611: 
krauss@19770: 	val (curry_info, name, (data, thy)) = FundefMutual.prepare_fundef_mutual congs t_eqns thy
krauss@19583: 	val Prep {complete, compat, ...} = data
krauss@19564: 
krauss@19564: 	val props = (complete :: compat) (*(complete :: fst (chop 110 compat))*)
krauss@19564:     in
krauss@19564: 	thy |> ProofContext.init
krauss@19611: 	    |> Proof.theorem_i PureThy.internalK NONE (fundef_afterqed congs curry_info name data names atts) NONE ("", [])
wenzelm@19585: 	    (map (fn t => (("", []), [(t, [])])) props)
krauss@19564:     end
krauss@19564: 
krauss@19564: 
krauss@19770: fun total_termination_afterqed name (Mutual {parts, ...}) thmss thy =
krauss@19564:     let
krauss@19564: 	val totality = hd (hd thmss)
krauss@19564: 
krauss@19770: 	val (FundefMResult {psimps, simple_pinducts, ... }, Mutual {parts, ...}, names, atts)
krauss@19564: 	  = the (get_fundef_data name thy)
krauss@19564: 
krauss@19564: 	val remove_domain_condition = full_simplify (HOL_basic_ss addsimps [totality, True_implies])
krauss@19564: 
krauss@19770: 	val tsimps = map (map remove_domain_condition) psimps
krauss@19770: 	val tinduct = map remove_domain_condition simple_pinducts
krauss@19770: 
krauss@19784:         val has_guards = exists ((fn (Const ("Trueprop", _) $ _) => false | _ => true) o prop_of) (flat tsimps)
krauss@19784:         val allatts = if has_guards then [] else [RecfunCodegen.add NONE]
krauss@19784: 
krauss@19784:         val thy = fold2 (add_simps "simps" allatts) (parts ~~ tsimps) (names ~~ atts) thy
krauss@19564: 
krauss@19564: 	val thy = Theory.add_path name thy
krauss@19564: 		  
krauss@19770: 	val (_, thy) = PureThy.add_thmss [(("induct", map standard tinduct), [])] thy 
krauss@19564: 	val thy = Theory.parent_path thy
krauss@19564:     in
krauss@19564: 	thy
krauss@19564:     end
krauss@19564: 
krauss@19564: (*
krauss@19564: fun mk_partial_rules name D_name D domT idomT thmss thy =
krauss@19564:     let
krauss@19564: 	val [subs, dcl] = (hd thmss)
krauss@19564: 
krauss@19564: 	val {f_const, f_curried_const, G_const, R_const, G_elims, completeness, f_simps, names_attrs, subset_induct, ... }
krauss@19564: 	  = the (Symtab.lookup (FundefData.get thy) name)
krauss@19564: 
krauss@19564: 	val D_implies_dom = subs COMP (instantiate' [SOME (ctyp_of thy idomT)] 
krauss@19564: 						    [SOME (cterm_of thy D)]
krauss@19564: 						    subsetD)
krauss@19564: 
krauss@19564: 	val D_simps = map (curry op RS D_implies_dom) f_simps
krauss@19564: 
krauss@19564: 	val D_induct = subset_induct
krauss@19564: 			   |> cterm_instantiate [(cterm_of thy (Var (("D",0), fastype_of D)) ,cterm_of thy D)]
krauss@19564: 			   |> curry op COMP subs
krauss@19564: 			   |> curry op COMP (dcl |> forall_intr (cterm_of thy (Var (("z",0), idomT)))
krauss@19564: 						 |> forall_intr (cterm_of thy (Var (("x",0), idomT))))
krauss@19564: 
krauss@19564: 	val ([tinduct'], thy2) = PureThy.add_thms [((name ^ "_" ^ D_name ^ "_induct", D_induct), [])] thy
krauss@19564: 	val ([tsimps'], thy3) = PureThy.add_thmss [((name ^ "_" ^ D_name ^ "_simps", D_simps), [])] thy2
krauss@19564:     in
krauss@19564: 	thy3
krauss@19564:     end
krauss@19564: *)
krauss@19564:  
krauss@19564: 
krauss@19564: fun fundef_setup_termination_proof name NONE thy = 
krauss@19564:     let
krauss@19564: 	val name = if name = "" then get_last_fundef thy else name
krauss@19564: 	val data = the (get_fundef_data name thy)
krauss@19564: 
krauss@19770: 	val (res as FundefMResult {termination, ...}, mutual, _, _) = data
krauss@19564: 	val goal = FundefTermination.mk_total_termination_goal data
krauss@19564:     in
krauss@19564: 	thy |> ProofContext.init
krauss@19770: 	    |> ProofContext.note_thmss_i [(("termination", 
krauss@19770: 					    [ContextRules.intro_query NONE]), [([termination], [])])] |> snd
krauss@19770: 	    |> Proof.theorem_i PureThy.internalK NONE (total_termination_afterqed name mutual) NONE ("", [])
wenzelm@19585: 	    [(("", []), [(goal, [])])]
krauss@19564:     end	
krauss@19564:   | fundef_setup_termination_proof name (SOME (dom_name, dom)) thy =
krauss@19564:     let
krauss@19564: 	val name = if name = "" then get_last_fundef thy else name
krauss@19564: 	val data = the (get_fundef_data name thy)
krauss@19564: 	val (subs, dcl) = FundefTermination.mk_partial_termination_goal thy data dom
krauss@19564:     in
krauss@19564: 	thy |> ProofContext.init
krauss@19564: 	    |> Proof.theorem_i PureThy.internalK NONE (K I) NONE ("", [])
wenzelm@19585: 	    [(("", []), [(subs, []), (dcl, [])])]
krauss@19564:     end	
krauss@19564: 
krauss@19564: 
krauss@19611: val add_fundef = gen_add_fundef Attrib.attribute
krauss@19611: 
krauss@19564: 
krauss@19564: 
krauss@19564: (* congruence rules *)
krauss@19564: 
wenzelm@19617: val cong_add = Thm.declaration_attribute (map_fundef_congs o Drule.add_rule o safe_mk_meta_eq);
wenzelm@19617: val cong_del = Thm.declaration_attribute (map_fundef_congs o Drule.del_rule o safe_mk_meta_eq);
krauss@19564: 
krauss@19564: 
krauss@19564: (* setup *)
krauss@19564: 
krauss@19564: val setup = FundefData.init #> FundefCongs.init 
krauss@19564: 	#>  Attrib.add_attributes
krauss@19564: 		[("fundef_cong", Attrib.add_del_args cong_add cong_del, "declaration of congruence rule for function definitions")]
krauss@19564: 
krauss@19564: 
krauss@19770: val get_congs = FundefCommon.get_fundef_congs o Context.Theory
krauss@19770: 
krauss@19770: 
krauss@19564: (* outer syntax *)
krauss@19564: 
krauss@19564: local structure P = OuterParse and K = OuterKeyword in
krauss@19564: 
krauss@19564: val function_decl =
krauss@19564:     Scan.repeat1 (P.opt_thm_name ":" -- P.prop);
krauss@19564: 
krauss@19564: val functionP =
krauss@19564:   OuterSyntax.command "function" "define general recursive functions" K.thy_goal
krauss@19770:     (P.and_list1 function_decl >> (fn eqnss =>
krauss@19770:       Toplevel.print o Toplevel.theory_to_proof (add_fundef eqnss)));
krauss@19564: 
krauss@19564: val terminationP =
krauss@19564:   OuterSyntax.command "termination" "prove termination of a recursive function" K.thy_goal
krauss@19564:   ((Scan.optional P.name "" -- Scan.option (P.$$$ "(" |-- Scan.optional (P.name --| P.$$$ ":") "dom" -- P.term --| P.$$$ ")"))
krauss@19564:        >> (fn (name,dom) =>
krauss@19564: 	      Toplevel.print o Toplevel.theory_to_proof (fundef_setup_termination_proof name dom)));
krauss@19564: 
krauss@19564: val _ = OuterSyntax.add_parsers [functionP];
krauss@19564: val _ = OuterSyntax.add_parsers [terminationP];
krauss@19564: 
krauss@19564: 
krauss@19564: end;
krauss@19564: 
krauss@19564: 
wenzelm@19585: end