author | wenzelm |
Mon, 07 Mar 2016 21:09:28 +0100 | |
changeset 62549 | 9498623b27f0 |
parent 61262 | 7bd1eb4b056e |
child 62538 | 85ebb645b1a3 |
permissions | -rw-r--r-- |
(* Title: Tools/Code/code_preproc.ML Author: Florian Haftmann, TU Muenchen Preprocessing code equations into a well-sorted system in a graph with explicit dependencies. *) signature CODE_PREPROC = sig val map_pre: (Proof.context -> Proof.context) -> theory -> theory val map_post: (Proof.context -> Proof.context) -> theory -> theory val add_functrans: string * (Proof.context -> (thm * bool) list -> (thm * bool) list option) -> theory -> theory val del_functrans: string -> theory -> theory val simple_functrans: (Proof.context -> thm list -> thm list option) -> Proof.context -> (thm * bool) list -> (thm * bool) list option val print_codeproc: Proof.context -> unit type code_algebra type code_graph val cert: code_graph -> string -> Code.cert val sortargs: code_graph -> string -> sort list val all: code_graph -> string list val pretty: Proof.context -> code_graph -> Pretty.T val obtain: bool -> Proof.context -> string list -> term list -> code_algebra * code_graph val dynamic_conv: Proof.context -> (code_algebra -> code_graph -> term -> conv) -> conv val dynamic_value: Proof.context -> ((term -> term) -> 'a -> 'b) -> (code_algebra -> code_graph -> term -> 'a) -> term -> 'b val static_conv: { ctxt: Proof.context, consts: string list } -> ({ algebra: code_algebra, eqngr: code_graph } -> Proof.context -> term -> conv) -> Proof.context -> conv val static_value: { ctxt: Proof.context, lift_postproc: ((term -> term) -> 'a -> 'b), consts: string list } -> ({ algebra: code_algebra, eqngr: code_graph } -> Proof.context -> term -> 'a) -> Proof.context -> term -> 'b val trace_none: Context.generic -> Context.generic val trace_all: Context.generic -> Context.generic val trace_only: string list -> Context.generic -> Context.generic val trace_only_ext: string list -> Context.generic -> Context.generic end structure Code_Preproc : CODE_PREPROC = struct (** preprocessor administration **) (* theory data *) datatype thmproc = Thmproc of { pre: simpset, post: simpset, functrans: (string * (serial * (Proof.context -> (thm * bool) list -> (thm * bool) list option))) list }; fun make_thmproc ((pre, post), functrans) = Thmproc { pre = pre, post = post, functrans = functrans }; fun map_thmproc f (Thmproc { pre, post, functrans }) = make_thmproc (f ((pre, post), functrans)); fun merge_thmproc (Thmproc { pre = pre1, post = post1, functrans = functrans1 }, Thmproc { pre = pre2, post = post2, functrans = functrans2 }) = let val pre = Simplifier.merge_ss (pre1, pre2); val post = Simplifier.merge_ss (post1, post2); val functrans = AList.merge (op =) (eq_fst (op =)) (functrans1, functrans2) handle AList.DUP => error ("Duplicate function transformer"); in make_thmproc ((pre, post), functrans) end; structure Code_Preproc_Data = Theory_Data ( type T = thmproc; val empty = make_thmproc ((Simplifier.empty_ss, Simplifier.empty_ss), []); val extend = I; val merge = merge_thmproc; ); fun the_thmproc thy = case Code_Preproc_Data.get thy of Thmproc x => x; fun delete_force msg key xs = if AList.defined (op =) xs key then AList.delete (op =) key xs else error ("No such " ^ msg ^ ": " ^ quote key); val map_data = Code_Preproc_Data.map o map_thmproc; val map_pre_post = map_data o apfst; fun map_simpset which f thy = map_pre_post (which (simpset_map (Proof_Context.init_global thy) f)) thy; val map_pre = map_simpset apfst; val map_post = map_simpset apsnd; fun process_unfold add_del = map_pre o add_del; fun process_post add_del = map_post o add_del; fun process_abbrev add_del raw_thm thy = let val ctxt = Proof_Context.init_global thy; val thm = Local_Defs.meta_rewrite_rule ctxt raw_thm; val thm_sym = Thm.symmetric thm; in thy |> map_pre_post (fn (pre, post) => (pre |> simpset_map ctxt (add_del thm_sym), post |> simpset_map ctxt (add_del thm))) end; fun add_functrans (name, f) = (map_data o apsnd) (AList.update (op =) (name, (serial (), f))); fun del_functrans name = (map_data o apsnd) (delete_force "function transformer" name); (* algebra of sandwiches: cterm transformations with pending postprocessors *) fun matches_transitive eq1 eq2 = Thm.rhs_of eq1 aconvc Thm.lhs_of eq2; fun trans_comb eq1 eq2 = (*explicit assertions: evaluation conversion stacks are error-prone*) if Thm.is_reflexive eq1 then (@{assert} (matches_transitive eq1 eq2); eq2) else if Thm.is_reflexive eq2 then (@{assert} (matches_transitive eq1 eq2); eq1) else Thm.transitive eq1 eq2; fun trans_conv_rule conv eq = trans_comb eq (conv (Thm.rhs_of eq)); structure Sandwich : sig type T = Proof.context -> cterm -> (thm -> thm) * cterm; val chain: T -> T -> T val lift: (Proof.context -> cterm -> (cterm -> thm) * thm) -> T val conversion: T -> (Proof.context -> term -> conv) -> Proof.context -> conv; val evaluation: T -> ((term -> term) -> 'a -> 'b) -> (Proof.context -> term -> 'a) -> Proof.context -> term -> 'b; end = struct type T = Proof.context -> cterm -> (thm -> thm) * cterm; fun chain sandwich2 sandwich1 ctxt = sandwich1 ctxt ##>> sandwich2 ctxt #>> (op o); fun lift conv_sandwhich ctxt ct = let val (postproc_conv, eq) = conv_sandwhich ctxt ct; fun potentail_trans_comb eq1 eq2 = if matches_transitive eq1 eq2 then trans_comb eq1 eq2 else eq2; (*weakened protocol for plain term evaluation*) in (trans_conv_rule postproc_conv o potentail_trans_comb eq, Thm.rhs_of eq) end; fun conversion sandwich conv ctxt ct = let val (postproc, ct') = sandwich ctxt ct; in postproc (conv ctxt (Thm.term_of ct') ct') end; fun evaluation sandwich lift_postproc eval ctxt t = let val (postproc, ct') = sandwich ctxt (Thm.cterm_of ctxt t); in Thm.term_of ct' |> eval ctxt |> lift_postproc (Thm.term_of o Thm.rhs_of o postproc o Thm.reflexive o Thm.cterm_of ctxt) end; end; (* post- and preprocessing *) fun normalized_tfrees_sandwich ctxt ct = let val t = Thm.term_of ct; val vs_original = fold_term_types (K (fold_atyps (insert (eq_fst op =) o dest_TFree))) t []; val vs_normalized = Name.invent_names Name.context Name.aT (map snd vs_original); val normalize = map_type_tfree (TFree o the o AList.lookup (op =) (vs_original ~~ vs_normalized)); val normalization = map2 (fn (v, sort) => fn (v', _) => (((v', 0), sort), Thm.ctyp_of ctxt (TFree (v, sort)))) vs_original vs_normalized; in if eq_list (eq_fst (op =)) (vs_normalized, vs_original) then (I, ct) else (Thm.instantiate (normalization, []) o Thm.varifyT_global, Thm.cterm_of ctxt (map_types normalize t)) end; fun no_variables_sandwich ctxt ct = let val all_vars = fold_aterms (fn t as Free _ => insert (op aconvc) (Thm.cterm_of ctxt t) | t as Var _ => insert (op aconvc) (Thm.cterm_of ctxt t) | _ => I) (Thm.term_of ct) []; fun apply_beta var thm = Thm.combination thm (Thm.reflexive var) |> Conv.fconv_rule (Conv.arg_conv (Conv.try_conv (Thm.beta_conversion false))) |> Conv.fconv_rule (Conv.arg1_conv (Thm.beta_conversion false)); in if null all_vars then (I, ct) else (fold apply_beta all_vars, fold_rev Thm.lambda all_vars ct) end; fun simplifier_conv_sandwich ctxt = let val thy = Proof_Context.theory_of ctxt; val pre = (#pre o the_thmproc) thy; val post = (#post o the_thmproc) thy; fun pre_conv ctxt' = Simplifier.rewrite (put_simpset pre ctxt') #> trans_conv_rule (Axclass.unoverload_conv (Proof_Context.theory_of ctxt')) fun post_conv ctxt' = Axclass.overload_conv (Proof_Context.theory_of ctxt') #> trans_conv_rule (Simplifier.rewrite (put_simpset post ctxt')) in fn ctxt' => pre_conv ctxt' #> pair (post_conv ctxt') end; fun simplifier_sandwich ctxt = Sandwich.lift (simplifier_conv_sandwich ctxt); fun value_sandwich ctxt = normalized_tfrees_sandwich |> Sandwich.chain no_variables_sandwich |> Sandwich.chain (simplifier_sandwich ctxt); fun print_codeproc ctxt = let val thy = Proof_Context.theory_of ctxt; val pre = (#pre o the_thmproc) thy; val post = (#post o the_thmproc) thy; val functrans = (map fst o #functrans o the_thmproc) thy; in Pretty.writeln_chunks [ Pretty.block [ Pretty.str "preprocessing simpset:", Pretty.fbrk, Simplifier.pretty_simpset true (put_simpset pre ctxt) ], Pretty.block [ Pretty.str "postprocessing simpset:", Pretty.fbrk, Simplifier.pretty_simpset true (put_simpset post ctxt) ], Pretty.block ( Pretty.str "function transformers:" :: Pretty.fbrk :: (Pretty.fbreaks o map Pretty.str) functrans ) ] end; fun simple_functrans f ctxt eqns = case f ctxt (map fst eqns) of SOME thms' => SOME (map (rpair (forall snd eqns)) thms') | NONE => NONE; (** sort algebra and code equation graph types **) type code_algebra = (sort -> sort) * Sorts.algebra; type code_graph = ((string * sort) list * Code.cert) Graph.T; fun get_node eqngr const = Graph.get_node eqngr const handle Graph.UNDEF _ => error ("No such constant in code equation graph: " ^ quote const); fun cert eqngr = snd o get_node eqngr; fun sortargs eqngr = map snd o fst o get_node eqngr; fun all eqngr = Graph.keys eqngr; fun pretty ctxt eqngr = let val thy = Proof_Context.theory_of ctxt; in AList.make (snd o Graph.get_node eqngr) (Graph.keys eqngr) |> (map o apfst) (Code.string_of_const thy) |> sort (string_ord o apply2 fst) |> map (fn (s, cert) => (Pretty.block o Pretty.fbreaks) (Pretty.str s :: Code.pretty_cert thy cert)) |> Pretty.chunks end; (** simplifier tracing **) structure Trace_Switch = Generic_Data ( type T = string list option; val empty = SOME []; val extend = I; fun merge (NONE, _) = NONE | merge (_, NONE) = NONE | merge (SOME cs1, SOME cs2) = SOME (Library.merge (op =) (cs1, cs2)); ); val trace_none = Trace_Switch.put (SOME []); val trace_all = Trace_Switch.put NONE; fun gen_trace_only prep_const raw_cs context = let val cs = map (prep_const (Context.theory_of context)) raw_cs; in Trace_Switch.put (SOME cs) context end; val trace_only = gen_trace_only (K I); val trace_only_ext = gen_trace_only Code.read_const; fun switch_trace c ctxt = let val d = Trace_Switch.get (Context.Proof ctxt); val switch = case d of NONE => true | SOME cs => member (op =) cs c; val _ = if switch then tracing ("Preprocessing function equations for " ^ Code.string_of_const (Proof_Context.theory_of ctxt) c) else (); in Config.put simp_trace switch ctxt end; (** the Waisenhaus algorithm **) (* auxiliary *) fun is_proper_class thy = can (Axclass.get_info thy); fun complete_proper_sort thy = Sign.complete_sort thy #> filter (is_proper_class thy); fun inst_params thy tyco = map (fn (c, _) => Axclass.param_of_inst thy (c, tyco)) o maps (#params o Axclass.get_info thy); (* data structures *) datatype const = Fun of string | Inst of class * string; fun const_ord (Fun c1, Fun c2) = fast_string_ord (c1, c2) | const_ord (Inst class_tyco1, Inst class_tyco2) = prod_ord fast_string_ord fast_string_ord (class_tyco1, class_tyco2) | const_ord (Fun _, Inst _) = LESS | const_ord (Inst _, Fun _) = GREATER; type var = const * int; structure Vargraph = Graph(type key = var val ord = prod_ord const_ord int_ord); datatype styp = Tyco of string * styp list | Var of var | Free; fun styp_of c_lhs (Type (tyco, tys)) = Tyco (tyco, map (styp_of c_lhs) tys) | styp_of c_lhs (TFree (v, _)) = case c_lhs of SOME (c, lhs) => Var (Fun c, find_index (fn (v', _) => v = v') lhs) | NONE => Free; type vardeps_data = ((string * styp list) list * class list) Vargraph.T * (((string * sort) list * Code.cert) Symtab.table * (class * string) list); val empty_vardeps_data : vardeps_data = (Vargraph.empty, (Symtab.empty, [])); (* retrieving equations and instances from the background context *) fun obtain_eqns ctxt eqngr c = case try (Graph.get_node eqngr) c of SOME (lhs, cert) => ((lhs, []), cert) | NONE => let val thy = Proof_Context.theory_of ctxt; val functrans = (map (fn (_, (_, f)) => f ctxt) o #functrans o the_thmproc) thy; val cert = Code.get_cert (switch_trace c ctxt) functrans c; val (lhs, rhss) = Code.typargs_deps_of_cert thy cert; in ((lhs, rhss), cert) end; fun obtain_instance ctxt arities (inst as (class, tyco)) = case AList.lookup (op =) arities inst of SOME classess => (classess, ([], [])) | NONE => let val thy = Proof_Context.theory_of ctxt; val all_classes = complete_proper_sort thy [class]; val super_classes = remove (op =) class all_classes; val classess = map (complete_proper_sort thy) (Proof_Context.arity_sorts ctxt tyco [class]); val inst_params = inst_params thy tyco all_classes; in (classess, (super_classes, inst_params)) end; (* computing instantiations *) fun add_classes ctxt arities eqngr c_k new_classes vardeps_data = let val (styps, old_classes) = Vargraph.get_node (fst vardeps_data) c_k; val diff_classes = new_classes |> subtract (op =) old_classes; in if null diff_classes then vardeps_data else let val c_ks = Vargraph.immediate_succs (fst vardeps_data) c_k |> insert (op =) c_k; in vardeps_data |> (apfst o Vargraph.map_node c_k o apsnd) (append diff_classes) |> fold (fn styp => fold (ensure_typmatch_inst ctxt arities eqngr styp) new_classes) styps |> fold (fn c_k => add_classes ctxt arities eqngr c_k diff_classes) c_ks end end and add_styp ctxt arities eqngr c_k new_tyco_styps vardeps_data = let val (old_tyco_stypss, classes) = Vargraph.get_node (fst vardeps_data) c_k; in if member (op =) old_tyco_stypss new_tyco_styps then vardeps_data else vardeps_data |> (apfst o Vargraph.map_node c_k o apfst) (cons new_tyco_styps) |> fold (ensure_typmatch_inst ctxt arities eqngr new_tyco_styps) classes end and add_dep ctxt arities eqngr c_k c_k' vardeps_data = let val (_, classes) = Vargraph.get_node (fst vardeps_data) c_k; in vardeps_data |> add_classes ctxt arities eqngr c_k' classes |> apfst (Vargraph.add_edge (c_k, c_k')) end and ensure_typmatch_inst ctxt arities eqngr (tyco, styps) class vardeps_data = if can (Proof_Context.arity_sorts ctxt tyco) [class] then vardeps_data |> ensure_inst ctxt arities eqngr (class, tyco) |> fold_index (fn (k, styp) => ensure_typmatch ctxt arities eqngr styp (Inst (class, tyco), k)) styps else vardeps_data (*permissive!*) and ensure_inst ctxt arities eqngr (inst as (class, tyco)) (vardeps_data as (_, (_, insts))) = if member (op =) insts inst then vardeps_data else let val (classess, (super_classes, inst_params)) = obtain_instance ctxt arities inst; in vardeps_data |> (apsnd o apsnd) (insert (op =) inst) |> fold_index (fn (k, _) => apfst (Vargraph.new_node ((Inst (class, tyco), k), ([] ,[])))) classess |> fold (fn super_class => ensure_inst ctxt arities eqngr (super_class, tyco)) super_classes |> fold (ensure_fun ctxt arities eqngr) inst_params |> fold_index (fn (k, classes) => add_classes ctxt arities eqngr (Inst (class, tyco), k) classes #> fold (fn super_class => add_dep ctxt arities eqngr (Inst (super_class, tyco), k) (Inst (class, tyco), k)) super_classes #> fold (fn inst_param => add_dep ctxt arities eqngr (Fun inst_param, k) (Inst (class, tyco), k) ) inst_params ) classess end and ensure_typmatch ctxt arities eqngr (Tyco tyco_styps) c_k vardeps_data = vardeps_data |> add_styp ctxt arities eqngr c_k tyco_styps | ensure_typmatch ctxt arities eqngr (Var c_k') c_k vardeps_data = vardeps_data |> add_dep ctxt arities eqngr c_k c_k' | ensure_typmatch ctxt arities eqngr Free c_k vardeps_data = vardeps_data and ensure_rhs ctxt arities eqngr (c', styps) vardeps_data = vardeps_data |> ensure_fun ctxt arities eqngr c' |> fold_index (fn (k, styp) => ensure_typmatch ctxt arities eqngr styp (Fun c', k)) styps and ensure_fun ctxt arities eqngr c (vardeps_data as (_, (eqntab, _))) = if Symtab.defined eqntab c then vardeps_data else let val ((lhs, rhss), eqns) = obtain_eqns ctxt eqngr c; val rhss' = (map o apsnd o map) (styp_of (SOME (c, lhs))) rhss; in vardeps_data |> (apsnd o apfst) (Symtab.update_new (c, (lhs, eqns))) |> fold_index (fn (k, _) => apfst (Vargraph.new_node ((Fun c, k), ([] ,[])))) lhs |> fold_index (fn (k, (_, sort)) => add_classes ctxt arities eqngr (Fun c, k) (complete_proper_sort (Proof_Context.theory_of ctxt) sort)) lhs |> fold (ensure_rhs ctxt arities eqngr) rhss' end; (* applying instantiations *) fun dicts_of ctxt (proj_sort, algebra) (T, sort) = let val thy = Proof_Context.theory_of ctxt; fun class_relation (x, _) _ = x; fun type_constructor (tyco, _) xs class = inst_params thy tyco (Sorts.complete_sort algebra [class]) @ (maps o maps) fst xs; fun type_variable (TFree (_, sort)) = map (pair []) (proj_sort sort); in flat (Sorts.of_sort_derivation algebra { class_relation = K class_relation, type_constructor = type_constructor, type_variable = type_variable } (T, proj_sort sort) handle Sorts.CLASS_ERROR _ => [] (*permissive!*)) end; fun add_arity ctxt vardeps (class, tyco) = AList.default (op =) ((class, tyco), map_range (fn k => (snd o Vargraph.get_node vardeps) (Inst (class, tyco), k)) (Sign.arity_number (Proof_Context.theory_of ctxt) tyco)); fun add_cert ctxt vardeps (c, (proto_lhs, proto_cert)) (rhss, eqngr) = if can (Graph.get_node eqngr) c then (rhss, eqngr) else let val thy = Proof_Context.theory_of ctxt; val lhs = map_index (fn (k, (v, _)) => (v, snd (Vargraph.get_node vardeps (Fun c, k)))) proto_lhs; val cert = proto_cert |> Code.constrain_cert thy (map (Sign.minimize_sort thy o snd) lhs) |> Code.conclude_cert; val (vs, rhss') = Code.typargs_deps_of_cert thy cert; val eqngr' = Graph.new_node (c, (vs, cert)) eqngr; in (map (pair c) rhss' @ rhss, eqngr') end; fun extend_arities_eqngr raw_ctxt cs ts (arities, (eqngr : code_graph)) = let val thy = Proof_Context.theory_of raw_ctxt; val {pre, ...} = the_thmproc thy; val ctxt = put_simpset pre raw_ctxt; val cs_rhss = (fold o fold_aterms) (fn Const (c_ty as (c, _)) => insert (op =) (c, (map (styp_of NONE) o Sign.const_typargs thy) c_ty) | _ => I) ts []; val (vardeps, (eqntab, insts)) = empty_vardeps_data |> fold (ensure_fun ctxt arities eqngr) cs |> fold (ensure_rhs ctxt arities eqngr) cs_rhss; val arities' = fold (add_arity ctxt vardeps) insts arities; val algebra = Sorts.subalgebra (Context.Theory thy) (is_proper_class thy) (AList.lookup (op =) arities') (Sign.classes_of thy); val (rhss, eqngr') = Symtab.fold (add_cert ctxt vardeps) eqntab ([], eqngr); fun deps_of (c, rhs) = c :: maps (dicts_of ctxt algebra) (rhs ~~ sortargs eqngr' c); val eqngr'' = fold (fn (c, rhs) => fold (curry Graph.add_edge c) (deps_of rhs)) rhss eqngr'; in (algebra, (arities', eqngr'')) end; (** store for preprocessed arities and code equations **) structure Wellsorted = Code_Data ( type T = ((string * class) * sort list) list * code_graph; val empty = ([], Graph.empty); ); (** retrieval and evaluation interfaces **) fun obtain ignore_cache ctxt consts ts = apsnd snd (Wellsorted.change_yield (if ignore_cache then NONE else SOME (Proof_Context.theory_of ctxt)) (extend_arities_eqngr ctxt consts ts)); fun dynamic_evaluator eval ctxt t = let val consts = fold_aterms (fn Const (c, _) => insert (op =) c | _ => I) t []; val (algebra, eqngr) = obtain false ctxt consts [t]; in eval algebra eqngr t end; fun dynamic_conv ctxt conv = Sandwich.conversion (value_sandwich ctxt) (dynamic_evaluator conv) ctxt; fun dynamic_value ctxt lift_postproc evaluator = Sandwich.evaluation (value_sandwich ctxt) lift_postproc (dynamic_evaluator evaluator) ctxt; fun static_conv { ctxt, consts } conv = let val (algebra, eqngr) = obtain true ctxt consts []; in Sandwich.conversion (value_sandwich ctxt) (conv { algebra = algebra, eqngr = eqngr }) end; fun static_value { ctxt, lift_postproc, consts } evaluator = let val (algebra, eqngr) = obtain true ctxt consts []; in Sandwich.evaluation (value_sandwich ctxt) lift_postproc (evaluator { algebra = algebra, eqngr = eqngr }) end; (** setup **) val _ = Theory.setup ( let fun mk_attribute f = Thm.declaration_attribute (fn thm => Context.mapping (f thm) I); fun add_del_attribute_parser process = Attrib.add_del (mk_attribute (process Simplifier.add_simp)) (mk_attribute (process Simplifier.del_simp)); in Attrib.setup @{binding code_unfold} (add_del_attribute_parser process_unfold) "preprocessing equations for code generator" #> Attrib.setup @{binding code_post} (add_del_attribute_parser process_post) "postprocessing equations for code generator" #> Attrib.setup @{binding code_abbrev} (add_del_attribute_parser process_abbrev) "post- and preprocessing equations for code generator" #> Attrib.setup @{binding code_preproc_trace} ((Scan.lift (Args.$$$ "off" >> K trace_none) || (Scan.lift (Args.$$$ "only" |-- Args.colon |-- Scan.repeat1 Parse.term)) >> trace_only_ext || Scan.succeed trace_all) >> (Thm.declaration_attribute o K)) "tracing of the code generator preprocessor" end); val _ = Outer_Syntax.command @{command_keyword print_codeproc} "print code preprocessor setup" (Scan.succeed (Toplevel.keep (print_codeproc o Toplevel.context_of))); end; (*struct*)