1(*  Title:      Tools/Code/code_preproc.ML
2    Author:     Florian Haftmann, TU Muenchen
3
4Preprocessing code equations into a well-sorted system
5in a graph with explicit dependencies.
6*)
7
8signature CODE_PREPROC =
9sig
10  val map_pre: (Proof.context -> Proof.context) -> theory -> theory
11  val map_post: (Proof.context -> Proof.context) -> theory -> theory
12  val add_functrans: string * (Proof.context -> (thm * bool) list -> (thm * bool) list option) -> theory -> theory
13  val del_functrans: string -> theory -> theory
14  val simple_functrans: (Proof.context -> thm list -> thm list option)
15    -> Proof.context -> (thm * bool) list -> (thm * bool) list option
16  val print_codeproc: Proof.context -> unit
17
18  type code_algebra
19  type code_graph
20  val cert: code_graph -> string -> Code.cert
21  val sortargs: code_graph -> string -> sort list
22  val all: code_graph -> string list
23  val pretty: Proof.context -> code_graph -> Pretty.T
24  val obtain: bool -> { ctxt: Proof.context, consts: string list, terms: term list } ->
25    { algebra: code_algebra, eqngr: code_graph }
26  val dynamic_conv: Proof.context
27    -> (code_algebra -> code_graph -> term -> conv) -> conv
28  val dynamic_value: Proof.context -> ((term -> term) -> 'a -> 'b)
29    -> (code_algebra -> code_graph -> term -> 'a) -> term -> 'b
30  val static_conv: { ctxt: Proof.context, consts: string list }
31    -> ({ algebra: code_algebra, eqngr: code_graph } -> Proof.context -> term -> conv)
32    -> Proof.context -> conv
33  val static_value: { ctxt: Proof.context, lift_postproc: ((term -> term) -> 'a -> 'b), consts: string list }
34    -> ({ algebra: code_algebra, eqngr: code_graph } -> Proof.context -> term -> 'a)
35    -> Proof.context -> term -> 'b
36
37  val trace_none: Context.generic -> Context.generic
38  val trace_all: Context.generic -> Context.generic
39  val trace_only: string list -> Context.generic -> Context.generic
40  val trace_only_ext: string list -> Context.generic -> Context.generic
41
42  val timing: bool Config.T
43  val timed: string -> ('a -> Proof.context) -> ('a -> 'b) -> 'a -> 'b
44  val timed_exec: string -> (unit -> 'a) -> Proof.context -> 'a
45  val timed_conv: string -> (Proof.context -> conv) -> Proof.context -> conv
46  val timed_value: string -> (Proof.context -> term -> 'a) -> Proof.context -> term -> 'a
47end
48
49structure Code_Preproc : CODE_PREPROC =
50struct
51
52(** timing **)
53
54val timing = Attrib.setup_config_bool @{binding code_timing} (K false);
55
56fun timed msg ctxt_of f x =
57  if Config.get (ctxt_of x) timing
58  then timeap_msg msg f x
59  else f x;
60
61fun timed_exec msg f ctxt =
62  if Config.get ctxt timing
63  then timeap_msg msg f ()
64  else f ();
65
66fun timed' msg f ctxt x =
67  if Config.get ctxt timing
68  then timeap_msg msg (f ctxt) x
69  else f ctxt x;
70
71val timed_conv = timed';
72val timed_value = timed';
73
74
75
76(** preprocessor administration **)
77
78(* theory data *)
79
80datatype thmproc = Thmproc of {
81  pre: simpset,
82  post: simpset,
83  functrans: (string * (serial * (Proof.context -> (thm * bool) list -> (thm * bool) list option))) list
84};
85
86fun make_thmproc ((pre, post), functrans) =
87  Thmproc { pre = pre, post = post, functrans = functrans };
88fun map_thmproc f (Thmproc { pre, post, functrans }) =
89  make_thmproc (f ((pre, post), functrans));
90fun merge_thmproc (Thmproc { pre = pre1, post = post1, functrans = functrans1 },
91  Thmproc { pre = pre2, post = post2, functrans = functrans2 }) =
92    let
93      val pre = Simplifier.merge_ss (pre1, pre2);
94      val post = Simplifier.merge_ss (post1, post2);
95      val functrans = AList.merge (op =) (eq_fst (op =)) (functrans1, functrans2)
96        handle AList.DUP => error ("Duplicate function transformer");
97    in make_thmproc ((pre, post), functrans) end;
98
99structure Code_Preproc_Data = Theory_Data
100(
101  type T = thmproc;
102  val empty = make_thmproc ((Simplifier.empty_ss, Simplifier.empty_ss), []);
103  val extend = I;
104  val merge = merge_thmproc;
105);
106
107fun the_thmproc thy = case Code_Preproc_Data.get thy
108 of Thmproc x => x;
109
110fun delete_force msg key xs =
111  if AList.defined (op =) xs key then AList.delete (op =) key xs
112  else error ("No such " ^ msg ^ ": " ^ quote key);
113
114val map_data = Code_Preproc_Data.map o map_thmproc;
115
116val map_pre_post = map_data o apfst;
117
118fun map_simpset which f thy =
119  map_pre_post (which (simpset_map (Proof_Context.init_global thy) f)) thy;
120val map_pre = map_simpset apfst;
121val map_post = map_simpset apsnd;
122
123fun process_unfold add_del = map_pre o add_del;
124fun process_post add_del = map_post o add_del;
125
126fun process_abbrev add_del raw_thm thy =
127  let
128    val ctxt = Proof_Context.init_global thy;
129    val thm = Local_Defs.meta_rewrite_rule ctxt raw_thm;
130    val thm_sym = Thm.symmetric thm;
131  in
132    thy |> map_pre_post (fn (pre, post) =>
133      (pre |> simpset_map ctxt (add_del thm_sym),
134       post |> simpset_map ctxt (add_del thm)))
135  end;
136
137fun add_functrans (name, f) = (map_data o apsnd)
138  (AList.update (op =) (name, (serial (), f)));
139
140fun del_functrans name = (map_data o apsnd)
141  (delete_force "function transformer" name);
142
143
144(* algebra of sandwiches: cterm transformations with pending postprocessors *)
145
146fun matches_transitive eq1 eq2 = Thm.rhs_of eq1 aconvc Thm.lhs_of eq2;
147
148fun trans_comb eq1 eq2 =
149  (*explicit assertions: evaluation conversion stacks are error-prone*)
150  if Thm.is_reflexive eq1 then (@{assert} (matches_transitive eq1 eq2); eq2)
151  else if Thm.is_reflexive eq2 then (@{assert} (matches_transitive eq1 eq2); eq1)
152  else Thm.transitive eq1 eq2;
153
154fun trans_conv_rule conv eq = trans_comb eq (conv (Thm.rhs_of eq));
155
156structure Sandwich : sig
157  type T = Proof.context -> cterm -> (Proof.context -> thm -> thm) * cterm;
158  val chain: T -> T -> T
159  val lift: (Proof.context -> cterm -> (Proof.context -> cterm -> thm) * thm) -> T
160  val conversion: T -> (Proof.context -> term -> conv) -> Proof.context -> conv;
161  val computation: T -> ((term -> term) -> 'a -> 'b) ->
162    (Proof.context -> term -> 'a) -> Proof.context -> term -> 'b;
163end = struct
164
165type T = Proof.context -> cterm -> (Proof.context -> thm -> thm) * cterm;
166
167fun chain sandwich2 sandwich1 ctxt =
168  sandwich1 ctxt
169  ##>> sandwich2 ctxt
170  #>> (fn (f, g) => fn ctxt => f ctxt o g ctxt);
171
172fun lift conv_sandwhich ctxt ct =
173  let
174    val (postproc_conv, eq) = conv_sandwhich ctxt ct;
175    fun potentail_trans_comb eq1 eq2 =
176      if matches_transitive eq1 eq2 then trans_comb eq1 eq2 else eq2;
177        (*weakened protocol for plain term evaluation*)
178  in (fn ctxt => trans_conv_rule (postproc_conv ctxt) o potentail_trans_comb eq, Thm.rhs_of eq) end;
179
180fun conversion sandwich conv ctxt ct =
181  let
182    val (postproc, ct') = sandwich ctxt ct;
183    val thm = conv ctxt (Thm.term_of ct') ct';
184    val thm' = postproc ctxt thm;
185  in thm' end;
186
187fun computation sandwich lift_postproc eval ctxt t =
188  let
189    val (postproc, ct') = sandwich ctxt (Thm.cterm_of ctxt t);
190    val result = eval ctxt (Thm.term_of ct');
191    val result' = lift_postproc
192      (Thm.term_of o Thm.rhs_of o postproc ctxt o Thm.reflexive o Thm.cterm_of ctxt)
193      result
194  in result' end;
195
196end;
197
198
199(* post- and preprocessing *)
200
201fun normalized_tfrees_sandwich ctxt ct =
202  let
203    val t = Thm.term_of ct;
204    val vs_original =
205      fold_term_types (K (fold_atyps (insert (eq_fst op =) o dest_TFree))) t [];
206    val vs_normalized = Name.invent_names Name.context Name.aT (map snd vs_original);
207    val normalize =
208      map_type_tfree (TFree o the o AList.lookup (op =) (vs_original ~~ vs_normalized));
209    val normalization =
210      map2 (fn (v, sort) => fn (v', _) => (((v', 0), sort), Thm.ctyp_of ctxt (TFree (v, sort))))
211        vs_original vs_normalized;
212  in
213    if eq_list (eq_fst (op =)) (vs_normalized, vs_original)
214    then (K I, ct)
215    else
216     (K (Thm.instantiate (normalization, []) o Thm.varifyT_global),
217      Thm.cterm_of ctxt (map_types normalize t))
218  end;
219
220fun no_variables_sandwich ctxt ct =
221  let
222    val all_vars = fold_aterms (fn t as Free _ => insert (op aconvc) (Thm.cterm_of ctxt t)
223      | t as Var _ => insert (op aconvc) (Thm.cterm_of ctxt t)
224      | _ => I) (Thm.term_of ct) [];
225    fun apply_beta var thm = Thm.combination thm (Thm.reflexive var)
226      |> Conv.fconv_rule (Conv.arg_conv (Conv.try_conv (Thm.beta_conversion false)))
227      |> Conv.fconv_rule (Conv.arg1_conv (Thm.beta_conversion false));
228  in
229    if null all_vars
230    then (K I, ct)
231    else (K (fold apply_beta all_vars), fold_rev Thm.lambda all_vars ct)
232  end;
233
234fun simplifier_conv_sandwich ctxt =
235  let
236    val thy = Proof_Context.theory_of ctxt;
237    val pre = (#pre o the_thmproc) thy;
238    val post = (#post o the_thmproc) thy;
239    fun pre_conv ctxt' =
240      Simplifier.rewrite (put_simpset pre ctxt')
241      #> trans_conv_rule (Axclass.unoverload_conv ctxt')
242      #> trans_conv_rule (Thm.eta_conversion);
243    fun post_conv ctxt'' =
244      Axclass.overload_conv ctxt''
245      #> trans_conv_rule (Simplifier.rewrite (put_simpset post ctxt''));
246  in
247    fn ctxt' => timed_conv "preprocessing term" pre_conv ctxt'
248      #> pair (timed_conv "postprocessing term" post_conv)
249  end;
250
251fun simplifier_sandwich ctxt =
252  Sandwich.lift (simplifier_conv_sandwich ctxt);
253
254fun value_sandwich ctxt =
255  normalized_tfrees_sandwich
256  |> Sandwich.chain no_variables_sandwich
257  |> Sandwich.chain (simplifier_sandwich ctxt);
258
259fun print_codeproc ctxt =
260  let
261    val thy = Proof_Context.theory_of ctxt;
262    val pre = (#pre o the_thmproc) thy;
263    val post = (#post o the_thmproc) thy;
264    val functrans = (map fst o #functrans o the_thmproc) thy;
265  in
266    Pretty.writeln_chunks [
267      Pretty.block [
268        Pretty.str "preprocessing simpset:",
269        Pretty.fbrk,
270        Simplifier.pretty_simpset true (put_simpset pre ctxt)
271      ],
272      Pretty.block [
273        Pretty.str "postprocessing simpset:",
274        Pretty.fbrk,
275        Simplifier.pretty_simpset true (put_simpset post ctxt)
276      ],
277      Pretty.block (
278        Pretty.str "function transformers:"
279        :: Pretty.fbrk
280        :: (Pretty.fbreaks o map Pretty.str) functrans
281      )
282    ]
283  end;
284
285fun simple_functrans f ctxt eqns = case f ctxt (map fst eqns)
286 of SOME thms' => SOME (map (rpair (forall snd eqns)) thms')
287  | NONE => NONE;
288
289
290(** sort algebra and code equation graph types **)
291
292type code_algebra = (sort -> sort) * Sorts.algebra;
293type code_graph = ((string * sort) list * Code.cert) Graph.T;
294
295fun get_node eqngr const = Graph.get_node eqngr const
296  handle Graph.UNDEF _ => error ("No such constant in code equation graph: " ^ quote const);
297
298fun cert eqngr = snd o get_node eqngr;
299fun sortargs eqngr = map snd o fst o get_node eqngr;
300fun all eqngr = Graph.keys eqngr;
301
302fun pretty ctxt eqngr =
303  let
304    val thy = Proof_Context.theory_of ctxt;
305  in
306    AList.make (snd o Graph.get_node eqngr) (Graph.keys eqngr)
307    |> (map o apfst) (Code.string_of_const thy)
308    |> sort (string_ord o apply2 fst)
309    |> (map o apsnd) (Code.pretty_cert thy)
310    |> filter_out (null o snd)
311    |> map (fn (s, ps) => (Pretty.block o Pretty.fbreaks) (Pretty.str s :: ps))
312    |> Pretty.chunks
313  end;
314
315
316(** simplifier tracing **)
317
318structure Trace_Switch = Generic_Data
319(
320  type T = string list option;
321  val empty = SOME [];
322  val extend = I;
323  fun merge (NONE, _) = NONE
324    | merge (_, NONE) = NONE
325    | merge (SOME cs1, SOME cs2) = SOME (Library.merge (op =) (cs1, cs2));
326);
327
328val trace_none = Trace_Switch.put (SOME []);
329
330val trace_all = Trace_Switch.put NONE;
331
332fun gen_trace_only prep_const raw_cs context =
333  let
334    val cs = map (prep_const (Context.theory_of context)) raw_cs;
335  in Trace_Switch.put (SOME cs) context end;
336
337val trace_only = gen_trace_only (K I);
338val trace_only_ext = gen_trace_only Code.read_const;
339
340fun switch_trace c ctxt =
341  let
342    val d = Trace_Switch.get (Context.Proof ctxt);
343    val switch = case d of NONE => true | SOME cs => member (op =) cs c;
344    val _ = if switch
345      then tracing ("Preprocessing function equations for "
346        ^ Code.string_of_const (Proof_Context.theory_of ctxt) c)
347      else ();
348  in Config.put simp_trace switch ctxt end;
349
350
351(** the Waisenhaus algorithm **)
352
353(* auxiliary *)
354
355fun is_proper_class thy = can (Axclass.get_info thy);
356
357fun complete_proper_sort thy =
358  Sign.complete_sort thy #> filter (is_proper_class thy);
359
360fun inst_params thy tyco =
361  map (fn (c, _) => Axclass.param_of_inst thy (c, tyco))
362    o maps (#params o Axclass.get_info thy);
363
364
365(* data structures *)
366
367datatype const = Fun of string | Inst of class * string;
368
369fun const_ord (Fun c1, Fun c2) = fast_string_ord (c1, c2)
370  | const_ord (Inst class_tyco1, Inst class_tyco2) =
371      prod_ord fast_string_ord fast_string_ord (class_tyco1, class_tyco2)
372  | const_ord (Fun _, Inst _) = LESS
373  | const_ord (Inst _, Fun _) = GREATER;
374
375type var = const * int;
376
377structure Vargraph =
378  Graph(type key = var val ord = prod_ord const_ord int_ord);
379
380datatype styp = Tyco of string * styp list | Var of var | Free;
381
382fun styp_of c_lhs (Type (tyco, tys)) = Tyco (tyco, map (styp_of c_lhs) tys)
383  | styp_of c_lhs (TFree (v, _)) = case c_lhs
384     of SOME (c, lhs) => Var (Fun c, find_index (fn (v', _) => v = v') lhs)
385      | NONE => Free;
386
387type vardeps_data = ((string * styp list) list * class list) Vargraph.T
388  * (((string * sort) list * Code.cert) Symtab.table
389    * (class * string) list);
390
391val empty_vardeps_data : vardeps_data =
392  (Vargraph.empty, (Symtab.empty, []));
393
394
395(* retrieving equations and instances from the background context *)
396
397fun obtain_eqns ctxt eqngr c =
398  case try (Graph.get_node eqngr) c
399   of SOME (lhs, cert) => ((lhs, []), cert)
400    | NONE => let
401        val thy = Proof_Context.theory_of ctxt;
402        val functrans = (map (fn (_, (_, f)) => f ctxt)
403          o #functrans o the_thmproc) thy;
404        val cert = Code.get_cert (switch_trace c ctxt) functrans c;
405        val (lhs, rhss) =
406          Code.typargs_deps_of_cert thy cert;
407      in ((lhs, rhss), cert) end;
408
409fun obtain_instance ctxt arities (inst as (class, tyco)) =
410  case AList.lookup (op =) arities inst
411   of SOME classess => (classess, ([], []))
412    | NONE => let
413        val thy = Proof_Context.theory_of ctxt;
414        val all_classes = complete_proper_sort thy [class];
415        val super_classes = remove (op =) class all_classes;
416        val classess =
417          map (complete_proper_sort thy)
418            (Proof_Context.arity_sorts ctxt tyco [class]);
419        val inst_params = inst_params thy tyco all_classes;
420      in (classess, (super_classes, inst_params)) end;
421
422
423(* computing instantiations *)
424
425fun add_classes ctxt arities eqngr c_k new_classes vardeps_data =
426  let
427    val (styps, old_classes) = Vargraph.get_node (fst vardeps_data) c_k;
428    val diff_classes = new_classes |> subtract (op =) old_classes;
429  in if null diff_classes then vardeps_data
430  else let
431    val c_ks = Vargraph.immediate_succs (fst vardeps_data) c_k |> insert (op =) c_k;
432  in
433    vardeps_data
434    |> (apfst o Vargraph.map_node c_k o apsnd) (append diff_classes)
435    |> fold (fn styp => fold (ensure_typmatch_inst ctxt arities eqngr styp) new_classes) styps
436    |> fold (fn c_k => add_classes ctxt arities eqngr c_k diff_classes) c_ks
437  end end
438and add_styp ctxt arities eqngr c_k new_tyco_styps vardeps_data =
439  let
440    val (old_tyco_stypss, classes) = Vargraph.get_node (fst vardeps_data) c_k;
441  in if member (op =) old_tyco_stypss new_tyco_styps then vardeps_data
442  else
443    vardeps_data
444    |> (apfst o Vargraph.map_node c_k o apfst) (cons new_tyco_styps)
445    |> fold (ensure_typmatch_inst ctxt arities eqngr new_tyco_styps) classes
446  end
447and add_dep ctxt arities eqngr c_k c_k' vardeps_data =
448  let
449    val (_, classes) = Vargraph.get_node (fst vardeps_data) c_k;
450  in
451    vardeps_data
452    |> add_classes ctxt arities eqngr c_k' classes
453    |> apfst (Vargraph.add_edge (c_k, c_k'))
454  end
455and ensure_typmatch_inst ctxt arities eqngr (tyco, styps) class vardeps_data =
456  if can (Proof_Context.arity_sorts ctxt tyco) [class]
457  then vardeps_data
458    |> ensure_inst ctxt arities eqngr (class, tyco)
459    |> fold_index (fn (k, styp) =>
460         ensure_typmatch ctxt arities eqngr styp (Inst (class, tyco), k)) styps
461  else vardeps_data (*permissive!*)
462and ensure_inst ctxt arities eqngr (inst as (class, tyco)) (vardeps_data as (_, (_, insts))) =
463  if member (op =) insts inst then vardeps_data
464  else let
465    val (classess, (super_classes, inst_params)) =
466      obtain_instance ctxt arities inst;
467  in
468    vardeps_data
469    |> (apsnd o apsnd) (insert (op =) inst)
470    |> fold_index (fn (k, _) =>
471         apfst (Vargraph.new_node ((Inst (class, tyco), k), ([] ,[])))) classess
472    |> fold (fn super_class => ensure_inst ctxt arities eqngr (super_class, tyco)) super_classes
473    |> fold (ensure_fun ctxt arities eqngr) inst_params
474    |> fold_index (fn (k, classes) =>
475         add_classes ctxt arities eqngr (Inst (class, tyco), k) classes
476         #> fold (fn super_class =>
477             add_dep ctxt arities eqngr (Inst (super_class, tyco), k)
478             (Inst (class, tyco), k)) super_classes
479         #> fold (fn inst_param =>
480             add_dep ctxt arities eqngr (Fun inst_param, k)
481             (Inst (class, tyco), k)
482             ) inst_params
483         ) classess
484  end
485and ensure_typmatch ctxt arities eqngr (Tyco tyco_styps) c_k vardeps_data =
486      vardeps_data
487      |> add_styp ctxt arities eqngr c_k tyco_styps
488  | ensure_typmatch ctxt arities eqngr (Var c_k') c_k vardeps_data =
489      vardeps_data
490      |> add_dep ctxt arities eqngr c_k c_k'
491  | ensure_typmatch ctxt arities eqngr Free c_k vardeps_data =
492      vardeps_data
493and ensure_rhs ctxt arities eqngr (c', styps) vardeps_data =
494  vardeps_data
495  |> ensure_fun ctxt arities eqngr c'
496  |> fold_index (fn (k, styp) =>
497       ensure_typmatch ctxt arities eqngr styp (Fun c', k)) styps
498and ensure_fun ctxt arities eqngr c (vardeps_data as (_, (eqntab, _))) =
499  if Symtab.defined eqntab c then vardeps_data
500  else let
501    val ((lhs, rhss), eqns) = obtain_eqns ctxt eqngr c;
502    val rhss' = (map o apsnd o map) (styp_of (SOME (c, lhs))) rhss;
503  in
504    vardeps_data
505    |> (apsnd o apfst) (Symtab.update_new (c, (lhs, eqns)))
506    |> fold_index (fn (k, _) =>
507         apfst (Vargraph.new_node ((Fun c, k), ([] ,[])))) lhs
508    |> fold_index (fn (k, (_, sort)) => add_classes ctxt arities eqngr (Fun c, k)
509         (complete_proper_sort (Proof_Context.theory_of ctxt) sort)) lhs
510    |> fold (ensure_rhs ctxt arities eqngr) rhss'
511  end;
512
513
514(* applying instantiations *)
515
516fun dicts_of ctxt (proj_sort, algebra) (T, sort) =
517  let
518    val thy = Proof_Context.theory_of ctxt;
519    fun class_relation _ (x, _) _ = x;
520    fun type_constructor (tyco, _) xs class =
521      inst_params thy tyco (Sorts.complete_sort algebra [class])
522        @ (maps o maps) fst xs;
523    fun type_variable (TFree (_, sort)) = map (pair []) (proj_sort sort);
524  in
525    flat (Sorts.of_sort_derivation algebra
526      { class_relation = K class_relation, type_constructor = type_constructor,
527        type_variable = type_variable } (T, proj_sort sort)
528       handle Sorts.CLASS_ERROR _ => [] (*permissive!*))
529  end;
530
531fun add_arity ctxt vardeps (class, tyco) =
532  AList.default (op =) ((class, tyco),
533    map_range (fn k => (snd o Vargraph.get_node vardeps) (Inst (class, tyco), k))
534      (Sign.arity_number (Proof_Context.theory_of ctxt) tyco));
535
536fun add_cert ctxt vardeps (c, (proto_lhs, proto_cert)) (rhss, eqngr) =
537  if can (Graph.get_node eqngr) c then (rhss, eqngr)
538  else let
539    val thy = Proof_Context.theory_of ctxt;
540    val lhs = map_index (fn (k, (v, _)) =>
541      (v, snd (Vargraph.get_node vardeps (Fun c, k)))) proto_lhs;
542    val cert = proto_cert
543      |> Code.constrain_cert thy (map (Sign.minimize_sort thy o snd) lhs)
544      |> Code.conclude_cert;
545    val (vs, rhss') = Code.typargs_deps_of_cert thy cert;
546    val eqngr' = Graph.new_node (c, (vs, cert)) eqngr;
547  in (map (pair c) rhss' @ rhss, eqngr') end;
548
549fun extend_arities_eqngr raw_ctxt cs ts (arities, (eqngr : code_graph)) =
550  let
551    val thy = Proof_Context.theory_of raw_ctxt;
552    val {pre, ...} = the_thmproc thy;
553    val ctxt = put_simpset pre raw_ctxt;
554    val cs_rhss = (fold o fold_aterms) (fn Const (c_ty as (c, _)) =>
555      insert (op =) (c, (map (styp_of NONE) o Sign.const_typargs thy) c_ty) | _ => I) ts [];
556    val (vardeps, (eqntab, insts)) = empty_vardeps_data
557      |> fold (ensure_fun ctxt arities eqngr) cs
558      |> fold (ensure_rhs ctxt arities eqngr) cs_rhss;
559    val arities' = fold (add_arity ctxt vardeps) insts arities;
560    val algebra = Sorts.subalgebra (Context.Theory thy) (is_proper_class thy)
561      (AList.lookup (op =) arities') (Sign.classes_of thy);
562    val (rhss, eqngr') = Symtab.fold (add_cert ctxt vardeps) eqntab ([], eqngr);
563    fun deps_of (c, rhs) = c :: maps (dicts_of ctxt algebra)
564      (rhs ~~ sortargs eqngr' c);
565    val eqngr'' = fold (fn (c, rhs) => fold
566      (curry Graph.add_edge c) (deps_of rhs)) rhss eqngr';
567  in (algebra, (arities', eqngr'')) end;
568
569
570(** store for preprocessed arities and code equations **)
571
572structure Wellsorted = Code_Data
573(
574  type T = ((string * class) * sort list) list * code_graph;
575  val empty = ([], Graph.empty);
576);
577
578
579(** retrieval and evaluation interfaces **)
580
581(*
582  naming conventions
583  * evaluator "eval" is either
584    * conversion "conv"
585    * value computation "comp"
586  * "evaluation" is a lifting of an evaluator
587*)
588
589fun obtain ignore_cache =
590  timed "preprocessing equations" #ctxt (fn { ctxt, consts, terms } =>
591    apsnd snd (Wellsorted.change_yield
592    (if ignore_cache then NONE else SOME (Proof_Context.theory_of ctxt))
593    (extend_arities_eqngr ctxt consts terms)))
594  #> (fn (algebra, eqngr) => { algebra = algebra, eqngr = eqngr });
595
596fun dynamic_evaluation eval ctxt t =
597  let
598    val consts = fold_aterms
599      (fn Const (c, _) => insert (op =) c | _ => I) t [];
600    val { algebra, eqngr } = obtain false { ctxt = ctxt, consts = consts, terms = [t] };
601  in eval algebra eqngr t end;
602
603fun static_evaluation ctxt consts eval =
604  eval (obtain true { ctxt = ctxt, consts = consts, terms = [] });
605
606fun dynamic_conv ctxt conv =
607  Sandwich.conversion (value_sandwich ctxt)
608    (dynamic_evaluation conv) ctxt;
609
610fun dynamic_value ctxt lift_postproc evaluator =
611  Sandwich.computation (value_sandwich ctxt) lift_postproc
612    (dynamic_evaluation evaluator) ctxt;
613
614fun static_conv { ctxt, consts } conv =
615  Sandwich.conversion (value_sandwich ctxt)
616    (static_evaluation ctxt consts conv);
617
618fun static_value { ctxt, lift_postproc, consts } comp =
619  Sandwich.computation (value_sandwich ctxt) lift_postproc
620    (static_evaluation ctxt consts comp);
621
622
623(** setup **)
624
625val _ = Theory.setup (
626  let
627    fun mk_attribute f = Thm.declaration_attribute (fn thm => Context.mapping (f thm) I);
628    fun add_del_attribute_parser process =
629      Attrib.add_del (mk_attribute (process Simplifier.add_simp))
630        (mk_attribute (process Simplifier.del_simp));
631  in
632    Attrib.setup @{binding code_unfold} (add_del_attribute_parser process_unfold)
633      "preprocessing equations for code generator"
634    #> Attrib.setup @{binding code_post} (add_del_attribute_parser process_post)
635      "postprocessing equations for code generator"
636    #> Attrib.setup @{binding code_abbrev} (add_del_attribute_parser process_abbrev)
637      "post- and preprocessing equations for code generator"
638    #> Attrib.setup @{binding code_preproc_trace}
639      ((Scan.lift (Args.$$$ "off" >> K trace_none)
640      || (Scan.lift (Args.$$$ "only" |-- Args.colon |-- Scan.repeat1 Parse.term))
641         >> trace_only_ext
642      || Scan.succeed trace_all)
643      >> (Thm.declaration_attribute o K)) "tracing of the code generator preprocessor"
644  end);
645
646val _ =
647  Outer_Syntax.command @{command_keyword print_codeproc} "print code preprocessor setup"
648    (Scan.succeed (Toplevel.keep (print_codeproc o Toplevel.context_of)));
649
650end; (*struct*)
651