# HG changeset patch # User wenzelm # Date 893842837 -7200 # Node ID 9be2bf0ce90951b931b8953af9e2aec85984c45b # Parent 72a46bd00c8d3cbec3751d0c665404a73134980d package extensible records with structural subtyping in HOL -- still experimental version; diff -r 72a46bd00c8d -r 9be2bf0ce909 src/HOL/Tools/record_package.ML --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/HOL/Tools/record_package.ML Wed Apr 29 11:40:37 1998 +0200 @@ -0,0 +1,572 @@ +(* Title: HOL/Tools/record_package.ML + ID: $Id$ + Author: Wolfgang Naraschewski and Markus Wenzel, TU Muenchen + +Extensible records with structural subtyping in HOL. + +TODO: + - record_info: tr' funs; + - trfuns for record types; + - field types: typedef; + - make selector types as general as possible (no!?); +*) + +signature RECORD_PACKAGE = +sig + val print_records: theory -> unit + val add_record: (string list * bstring) -> string option + -> (bstring * string) list -> theory -> theory + val add_record_i: (string list * bstring) -> (typ list * string) option + -> (bstring * typ) list -> theory -> theory + val setup: (theory -> theory) list +end; + +structure RecordPackage: RECORD_PACKAGE = +struct + + +(*** syntax operations ***) + +(** names **) + +(* name components *) + +val moreN = "more"; +val schemeN = "_scheme"; +val fieldN = "_field"; +val field_typeN = "_field_type"; +val fstN = "_val"; +val sndN = "_more"; +val updateN = "_update"; +val makeN = "make"; +val make_schemeN = "make_scheme"; + + +(* suffixes *) + +fun suffix sfx s = s ^ sfx; + +fun unsuffix sfx s = + let + val cs = explode s; + val prfx_len = size s - size sfx; + in + if prfx_len >= 0 andalso implode (drop (prfx_len, cs)) = sfx then + implode (take (prfx_len, cs)) + else raise LIST "unsuffix" + end; + + + +(** tuple operations **) + +(* more type class *) + +val moreS = ["more"]; + + +(* types *) + +fun mk_fieldT ((c, T), U) = Type (suffix field_typeN c, [T, U]); + +fun dest_fieldT (typ as Type (c_field_type, [T, U])) = + (case try (unsuffix field_typeN) c_field_type of + None => raise TYPE ("dest_fieldT", [typ], []) + | Some c => ((c, T), U)) + | dest_fieldT typ = raise TYPE ("dest_fieldT", [typ], []); + + +(* constructors *) + +fun mk_fieldC U (c, T) = (suffix fieldN c, T --> U --> mk_fieldT ((c, T), U)); + +fun mk_field ((c, t), u) = + let val T = fastype_of t and U = fastype_of u + in Const (suffix fieldN c, [T, U] ---> mk_fieldT ((c, T), U)) $ t $ u end; + + +(* destructors *) + +fun mk_fstC U (c, T) = (suffix fstN c, mk_fieldT ((c, T), U) --> T); +fun mk_sndC U (c, T) = (suffix sndN c, mk_fieldT ((c, T), U) --> U); + +fun dest_field fst_or_snd p = + let + val pT = fastype_of p; + val ((c, T), U) = dest_fieldT pT; + val (destN, destT) = if fst_or_snd then (fstN, T) else (sndN, U); + in Const (suffix destN c, pT --> destT) $ p end; + +val mk_fst = dest_field true; +val mk_snd = dest_field false; + + + +(** record operations **) + +(* types *) + +val mk_recordT = foldr mk_fieldT; + +fun dest_recordT T = + (case try dest_fieldT T of + None => ([], T) + | Some (c_T, U) => apfst (cons c_T) (dest_recordT U)); + +fun find_fieldT c rT = + (case assoc (fst (dest_recordT rT), c) of + None => raise TYPE ("find_field: " ^ c, [rT], []) + | Some T => T); + + +(* constructors *) + +val mk_record = foldr mk_field; + + +(* selectors *) + +fun mk_selC rT (c, T) = (c, rT --> T); + +fun mk_sel c r = + let val rT = fastype_of r + in Const (mk_selC rT (c, find_fieldT c rT)) $ r end; + + +(* updates *) + +fun mk_updateC rT (c, T) = (suffix updateN c, T --> rT --> rT); + +fun mk_update c x r = + let val rT = fastype_of r + in Const (mk_updateC rT (c, find_fieldT c rT)) $ x $ r end; + + + +(** concrete syntax for records **) + +(* parse translations *) + +fun field_tr (Const ("_field", _) $ Free (name, _) $ arg) = + Syntax.const (suffix fieldN name) $ arg + | field_tr t = raise TERM ("field_tr", [t]); + +fun fields_tr (Const ("_fields", _) $ field $ fields) = + field_tr field :: fields_tr fields + | fields_tr field = [field_tr field]; + +fun record_tr (*"_record"*) [fields] = + foldr (op $) (fields_tr fields, HOLogic.unit) + | record_tr (*"_record"*) ts = raise TERM ("record_tr", ts); + +fun record_scheme_tr (*"_record_scheme"*) [fields, more] = + foldr (op $) (fields_tr fields, more) + | record_scheme_tr (*"_record_scheme"*) ts = raise TERM ("record_scheme_tr", ts); + + +(* print translations *) (* FIXME tune, activate *) + +(* FIXME ... :: tms *) +fun fields_tr' (tm as Const (name_field, _) $ arg $ more) = + (case try (unsuffix fieldN) name_field of + Some name => + apfst (cons (Syntax.const "_field" $ Syntax.free name $ arg)) (fields_tr' more) + | None => ([], tm)) + | fields_tr' tm = ([], tm); + +fun record_tr' tm = + let + val mk_fields = foldr (fn (field, fields) => Syntax.const "_fields" $ field $ fields); + val (fields, more) = fields_tr' tm; + in + if HOLogic.is_unit more then + Syntax.const "_record" $ mk_fields (split_last fields) + else Syntax.const "_record_scheme" $ mk_fields (fields, more) + end; + +fun field_tr' name [arg, more] = record_tr' (Syntax.const name $ arg $ more) + | field_tr' _ _ = raise Match; + + + +(*** extend theory by record definition ***) + +(** record info **) + +(* type record_info and parent_info *) + +type record_info = + {args: (string * sort) list, + parent: (typ list * string) option, + fields: (string * typ) list, + simps: tthm list}; + +type parent_info = + {name: string, + fields: (string * typ) list, + simps: tthm list}; + + +(* theory data *) + +val recordsK = "HOL/records"; +exception Records of record_info Symtab.table; + +fun print_records thy = Display.print_data thy recordsK; + +local + val empty = Records Symtab.empty; + + fun prep_ext (x as Records _) = x; + + fun merge (Records tab1, Records tab2) = + Records (Symtab.merge (K true) (tab1, tab2)); + + fun print sg (Records tab) = + let + val prt_typ = Sign.pretty_typ sg; + val ext_const = Sign.cond_extern sg Sign.constK; + + fun pretty_parent None = [] + | pretty_parent (Some (Ts, name)) = + [Pretty.block [prt_typ (Type (name, Ts)), Pretty.str " +"]]; + + fun pretty_field (c, T) = Pretty.block + [Pretty.str (ext_const c), Pretty.str " ::", Pretty.brk 1, Pretty.quote (prt_typ T)]; + + fun pretty_record (name, {args, parent, fields, simps = _}) = Pretty.block (Pretty.fbreaks + (Pretty.block [prt_typ (Type (name, map TFree args)), Pretty.str " = "] :: + pretty_parent parent @ map pretty_field fields)); + in + seq (Pretty.writeln o pretty_record) (Symtab.dest tab) + end; +in + val record_thy_data = (recordsK, (empty, prep_ext, merge, print)); +end; + + +(* get and put records *) + +fun get_records thy = + (case Theory.get_data thy recordsK of + Records tab => tab + | _ => type_error recordsK); + +fun get_record thy name = Symtab.lookup (get_records thy, name); + + +fun put_records tab thy = + Theory.put_data (recordsK, Records tab) thy; + +fun put_new_record name info thy = + thy |> put_records + (Symtab.update_new ((name, info), get_records thy) + handle Symtab.DUP _ => error ("Duplicate definition of record " ^ quote name)); + + +(* parent records *) + +fun inst_record thy (types, name) = + let + val sign = Theory.sign_of thy; + fun err msg = error (msg ^ " parent record " ^ quote name); + + val {args, parent, fields, simps} = + (case get_record thy name of Some info => info | None => err "Unknown"); + + fun bad_inst ((x, S), T) = + if Sign.of_sort sign (T, S) then None else Some x + val bads = mapfilter bad_inst (args ~~ types); + + val inst = map fst args ~~ types; + val subst = Term.map_type_tfree (fn (x, _) => the (assoc (inst, x))); + in + if length types <> length args then + err "Bad number of arguments for" + else if not (null bads) then + err ("Ill-sorted instantiation of " ^ commas bads ^ " in") + else (apsome (apfst (map subst)) parent, map (apsnd subst) fields, simps) + end; + +fun add_parents thy (None, parents) = parents + | add_parents thy (Some (types, name), parents) = + let val (pparent, pfields, psimps) = inst_record thy (types, name) + in add_parents thy (pparent, {name = name, fields = pfields, simps = psimps} :: parents) end; + + + +(** record theorems **) + +(* proof by simplification *) + +fun prove_simp thy opt_ss simps = + let val ss = if_none opt_ss HOL_basic_ss addsimps simps in + fn goal => Goals.prove_goalw_cterm [] (Thm.cterm_of (sign_of thy) goal) + (K [ALLGOALS (Simplifier.simp_tac ss)]) + end; + + + +(** internal theory extender **) + +(*do the actual record definition, assuming that all arguments are + well-formed*) + +fun record_definition (args, bname) parent (parents: parent_info list) bfields thy = + let + val sign = Theory.sign_of thy; + val full = Sign.full_name_path sign bname; + + + (* input *) + + val alphas = map fst args; + val name = Sign.full_name sign bname; (* FIXME !? *) + val parent_fields = flat (map #fields parents); + val fields = map (apfst full) bfields; + + val all_fields = parent_fields @ fields; + val all_types = map snd all_fields; + + + (* term / type components *) + + val zeta = variant alphas "'z"; + val moreT = TFree (zeta, moreS); + + val xs = variantlist (map fst bfields, []); + val vars = map2 Free (xs, map snd fields); + val more = Free (variant xs moreN, moreT); + + val rec_schemeT = mk_recordT (all_fields, moreT); + val recT = mk_recordT (all_fields, HOLogic.unitT); + + (* FIXME tune *) + val make_schemeT = all_types ---> moreT --> rec_schemeT; + val make_scheme = Const (full make_schemeN, make_schemeT); + val makeT = all_types ---> recT; + val make = Const (full makeN, makeT); + + val parent_more = funpow (length parent_fields) mk_snd; + + + (* prepare type definitions *) + + (*field types*) + fun mk_fieldT_spec ((c, T), a) = + (suffix field_typeN c, [a, zeta], + HOLogic.mk_prodT (TFree (a, HOLogic.termS), moreT), Syntax.NoSyn); + val fieldT_specs = map2 mk_fieldT_spec (bfields, alphas); + + (*record types*) + val recordT_specs = + [(suffix schemeN bname, alphas @ [zeta], rec_schemeT, Syntax.NoSyn), + (bname, alphas, recT, Syntax.NoSyn)]; + + + (* prepare declarations *) + + val field_decls = map (mk_fieldC moreT) fields; + val dest_decls = map (mk_fstC moreT) fields @ map (mk_sndC moreT) fields; + val sel_decls = map (mk_selC rec_schemeT) fields; + val update_decls = map (mk_updateC rec_schemeT) fields; + val make_decls = [(make_schemeN, make_schemeT), (makeN, makeT)]; + + + (* prepare definitions *) + + (*field constructors*) + fun mk_field_spec ((c, _), v) = + Logic.mk_defpair (mk_field ((c, v), more), HOLogic.mk_prod (v, more)); + val field_specs = map2 mk_field_spec (fields, vars); + + (*field destructors*) + fun mk_dest_spec dest dest' (c, T) = + let + val p = Free ("p", mk_fieldT ((c, T), moreT)); + val p' = Free ("p", HOLogic.mk_prodT (T, moreT)); (*Note: field types are abbreviations*) + in Logic.mk_defpair (dest p, dest' p') end; + val dest_specs = + map (mk_dest_spec mk_fst HOLogic.mk_fst) fields @ + map (mk_dest_spec mk_snd HOLogic.mk_snd) fields; + + (*field selectors*) (* FIXME tune *) + fun mk_sel_specs _ [] specs = rev specs + | mk_sel_specs prfx ((c, T) :: fs) specs = + let + val prfx' = prfx @ [(c, T)]; + val r = Free ("r", mk_recordT (prfx' @ fs, moreT)); + val spec = Logic.mk_defpair (mk_sel c r, mk_fst (funpow (length prfx) mk_snd r)); + in mk_sel_specs prfx' fs (spec :: specs) end; + val sel_specs = mk_sel_specs parent_fields fields []; + + (*updates*) + val update_specs = []; (* FIXME *) + + (*makes*) + val make_specs = + map Logic.mk_defpair + [(list_comb (make_scheme, vars) $ more, mk_record (map fst fields ~~ vars, more)), + (list_comb (make, vars), mk_record (map fst fields ~~ vars, HOLogic.unit))]; + + + (* 1st stage: defs_thy *) + + val defs_thy = + thy + |> Theory.add_path bname + |> Theory.add_tyabbrs_i (fieldT_specs @ recordT_specs) + |> (Theory.add_consts_i o map (Syntax.no_syn o apfst Sign.base_name)) + (field_decls @ dest_decls @ sel_decls @ update_decls @ make_decls) + |> (PureThy.add_defs_i o map Attribute.none) + (field_specs @ dest_specs @ sel_specs @ update_specs @ make_specs); + + local fun get_defs specs = map (PureThy.get_tthm defs_thy o fst) specs in + val make_defs = get_defs make_specs; + val field_defs = get_defs field_specs; + val sel_defs = get_defs sel_specs; + val update_defs = get_defs update_specs; + end; + + + (* 2nd stage: thms_thy *) + + val thms_thy = + defs_thy + |> (PureThy.add_tthmss o map Attribute.none) + [("make_defs", make_defs), + ("field_defs", field_defs), + ("sel_defs", sel_defs), + ("update_defs", update_defs)] +(* |> record_theorems FIXME *) + + + (* 3rd stage: final_thy *) + + val final_thy = + thms_thy + |> put_new_record name + {args = args, parent = parent, fields = fields, simps = [] (* FIXME *)} + |> Theory.parent_path; + + in final_thy end; + + + +(** theory extender interface **) + +(*do all preparations and error checks here, deferring the real work + to record_definition above*) + + +(* prepare arguments *) + +(*Note: read_raw_typ avoids expanding type abbreviations*) +fun read_raw_parent sign s = + (case Sign.read_raw_typ (sign, K None) s handle TYPE (msg, _, _) => error msg of + Type (name, Ts) => (Ts, name) + | _ => error ("Bad parent record specification: " ^ quote s)); + +fun read_typ sign (env, s) = + let + fun def_type (x, ~1) = assoc (env, x) + | def_type _ = None; + val T = Type.no_tvars (Sign.read_typ (sign, def_type) s) handle TYPE (msg, _, _) => error msg; + in (Term.add_typ_tfrees (T, env), T) end; + +fun cert_typ sign (env, raw_T) = + let val T = Type.no_tvars (Sign.certify_typ sign raw_T) handle TYPE (msg, _, _) => error msg + in (Term.add_typ_tfrees (T, env), T) end; + + +(* add_record *) + +fun gen_add_record prep_typ prep_raw_parent (params, bname) raw_parent raw_fields thy = + let + val _ = Theory.require thy "Record" "record definitions"; + val sign = Theory.sign_of thy; + + + (* parents *) + + fun prep_inst T = snd (cert_typ sign ([], T)); + + val parent = apsome (apfst (map prep_inst) o prep_raw_parent sign) raw_parent + handle ERROR => error ("The error(s) above in parent record specification"); + val parents = add_parents thy (parent, []); + + val init_env = + (case parent of + None => [] + | Some (types, _) => foldr Term.add_typ_tfrees (types, [])); + + + (* fields *) + + fun prep_fields (env, []) = (env, []) + | prep_fields (env, (c, raw_T) :: fs) = + let + val (env', T) = prep_typ sign (env, raw_T) handle ERROR => + error ("The error(s) above occured in field " ^ quote c); + val (env'', fs') = prep_fields (env', fs); + in (env'', (c, T) :: fs') end; + + val (envir, bfields) = prep_fields (init_env, raw_fields); + val envir_names = map fst envir; + + + (* args *) + + val defaultS = Sign.defaultS sign; + val args = map (fn x => (x, if_none (assoc (envir, x)) defaultS)) params; + + + (* errors *) + + val err_dup_parms = + (case duplicates params of + [] => [] + | dups => ["Duplicate parameters " ^ commas params]); + + val err_extra_frees = + (case gen_rems (op =) (envir_names, params) of + [] => [] + | extras => ["Extraneous free type variables " ^ commas extras]); + + val err_no_fields = if null bfields then ["No fields"] else []; + + val err_dup_fields = + (case duplicates (map fst bfields) of + [] => [] + | dups => ["Duplicate fields " ^ commas_quote dups]); + + val err_dup_sorts = + (case duplicates envir_names of + [] => [] + | dups => ["Inconsistent sort constraints for " ^ commas dups]); + + val errs = + err_dup_parms @ err_extra_frees @ err_no_fields @ err_dup_fields @ err_dup_sorts; + in + if null errs then () + else error (cat_lines errs); + + writeln ("Defining record " ^ quote bname ^ " ..."); + thy |> record_definition (args, bname) parent parents bfields + end + handle ERROR => error ("Failed to define record " ^ quote bname); + +val add_record = gen_add_record read_typ read_raw_parent; +val add_record_i = gen_add_record cert_typ (K I); + + + +(** setup theory **) + +val setup = + [Theory.init_data [record_thy_data], + Theory.add_trfuns + ([], [("_record", record_tr), ("_record_scheme", record_scheme_tr)], [], [])]; + + +end;