author  wenzelm 
Mon, 05 Sep 2005 17:38:18 +0200  
changeset 17261  193b84a70ca4 
parent 17203  29b2563f5c11 
child 17412  e26cb20ef0cc 
permissions  rwrr 
12447  1 
(* Title: HOL/recfun_codegen.ML 
2 
ID: $Id$ 

3 
Author: Stefan Berghofer, TU Muenchen 

4 

5 
Code generator for recursive functions. 

6 
*) 

7 

8 
signature RECFUN_CODEGEN = 

9 
sig 

16645  10 
val add: string option > theory attribute 
11 
val del: theory attribute 

12447  12 
val setup: (theory > theory) list 
13 
end; 

14 

15 
structure RecfunCodegen : RECFUN_CODEGEN = 

16 
struct 

17 

18 
open Codegen; 

19 

16424  20 
structure CodegenData = TheoryDataFun 
21 
(struct 

12447  22 
val name = "HOL/recfun_codegen"; 
16645  23 
type T = (thm * string option) list Symtab.table; 
12447  24 
val empty = Symtab.empty; 
25 
val copy = I; 

16424  26 
val extend = I; 
16645  27 
fun merge _ = Symtab.merge_multi' (Drule.eq_thm_prop o pairself fst); 
12447  28 
fun print _ _ = (); 
16424  29 
end); 
12447  30 

31 

32 
val dest_eqn = HOLogic.dest_eq o HOLogic.dest_Trueprop; 

15321
694f9d3ce90d
Reimplemented some operations on "code lemma" table to avoid that code
berghofe
parents:
15257
diff
changeset

33 
val lhs_of = fst o dest_eqn o prop_of; 
12447  34 
val const_of = dest_Const o head_of o fst o dest_eqn; 
35 

36 
fun warn thm = warning ("RecfunCodegen: Not a proper equation:\n" ^ 

37 
string_of_thm thm); 

38 

16645  39 
fun add optmod (p as (thy, thm)) = 
12447  40 
let 
12556  41 
val tab = CodegenData.get thy; 
12447  42 
val (s, _) = const_of (prop_of thm); 
15321
694f9d3ce90d
Reimplemented some operations on "code lemma" table to avoid that code
berghofe
parents:
15257
diff
changeset

43 
in 
694f9d3ce90d
Reimplemented some operations on "code lemma" table to avoid that code
berghofe
parents:
15257
diff
changeset

44 
if Pattern.pattern (lhs_of thm) then 
17261  45 
(CodegenData.put (Symtab.curried_update_multi (s, (thm, optmod)) tab) thy, thm) 
15321
694f9d3ce90d
Reimplemented some operations on "code lemma" table to avoid that code
berghofe
parents:
15257
diff
changeset

46 
else (warn thm; p) 
694f9d3ce90d
Reimplemented some operations on "code lemma" table to avoid that code
berghofe
parents:
15257
diff
changeset

47 
end handle TERM _ => (warn thm; p); 
12447  48 

14196  49 
fun del (p as (thy, thm)) = 
50 
let 

51 
val tab = CodegenData.get thy; 

52 
val (s, _) = const_of (prop_of thm); 

17261  53 
in case Symtab.curried_lookup tab s of 
15531  54 
NONE => p 
17261  55 
 SOME thms => (CodegenData.put (Symtab.curried_update (s, 
56 
gen_rem (eq_thm o apfst fst) (thms, thm)) tab) thy, thm) 

14196  57 
end handle TERM _ => (warn thm; p); 
58 

15321
694f9d3ce90d
Reimplemented some operations on "code lemma" table to avoid that code
berghofe
parents:
15257
diff
changeset

59 
fun del_redundant thy eqs [] = eqs 
694f9d3ce90d
Reimplemented some operations on "code lemma" table to avoid that code
berghofe
parents:
15257
diff
changeset

60 
 del_redundant thy eqs (eq :: eqs') = 
694f9d3ce90d
Reimplemented some operations on "code lemma" table to avoid that code
berghofe
parents:
15257
diff
changeset

61 
let 
694f9d3ce90d
Reimplemented some operations on "code lemma" table to avoid that code
berghofe
parents:
15257
diff
changeset

62 
val matches = curry 
17203  63 
(Pattern.matches thy o pairself (lhs_of o fst)) 
15321
694f9d3ce90d
Reimplemented some operations on "code lemma" table to avoid that code
berghofe
parents:
15257
diff
changeset

64 
in del_redundant thy (eq :: eqs) (filter_out (matches eq) eqs') end; 
694f9d3ce90d
Reimplemented some operations on "code lemma" table to avoid that code
berghofe
parents:
15257
diff
changeset

65 

16645  66 
fun get_equations thy defs (s, T) = 
17261  67 
(case Symtab.curried_lookup (CodegenData.get thy) s of 
16645  68 
NONE => ([], "") 
69 
 SOME thms => 

70 
let val thms' = del_redundant thy [] 

71 
(List.filter (fn (thm, _) => is_instance thy T 

72 
(snd (const_of (prop_of thm)))) thms) 

73 
in if null thms' then ([], "") 

74 
else (preprocess thy (map fst thms'), 

75 
case snd (snd (split_last thms')) of 

76 
NONE => (case get_defn thy defs s T of 

77 
NONE => thyname_of_const s thy 

78 
 SOME ((_, (thyname, _)), _) => thyname) 

79 
 SOME thyname => thyname) 

80 
end); 

12447  81 

16645  82 
fun mk_suffix thy defs (s, T) = (case get_defn thy defs s T of 
17144  83 
SOME (_, SOME i) => " def" ^ string_of_int i  _ => ""); 
12447  84 

85 
exception EQN of string * typ * string; 

86 

87 
fun cycle g (xs, x) = 

88 
if x mem xs then xs 

17144  89 
else Library.foldl (cycle g) (x :: xs, List.concat (Graph.find_paths (fst g) (x, x))); 
12447  90 

17144  91 
fun add_rec_funs thy defs gr dep eqs module = 
12447  92 
let 
16645  93 
fun dest_eq t = (fst (const_of t) ^ mk_suffix thy defs (const_of t), 
94 
dest_eqn (rename_term t)); 

12447  95 
val eqs' = map dest_eq eqs; 
96 
val (dname, _) :: _ = eqs'; 

97 
val (s, T) = const_of (hd eqs); 

98 

17144  99 
fun mk_fundef module fname prfx gr [] = (gr, []) 
100 
 mk_fundef module fname prfx gr ((fname', (lhs, rhs)) :: xs) = 

12447  101 
let 
17144  102 
val (gr1, pl) = invoke_codegen thy defs dname module false (gr, lhs); 
103 
val (gr2, pr) = invoke_codegen thy defs dname module false (gr1, rhs); 

104 
val (gr3, rest) = mk_fundef module fname' "and " gr2 xs 

12447  105 
in 
106 
(gr3, Pretty.blk (4, [Pretty.str (if fname = fname' then "  " else prfx), 

107 
pl, Pretty.str " =", Pretty.brk 1, pr]) :: rest) 

108 
end; 

109 

17144  110 
fun put_code module fundef = map_node dname 
111 
(K (SOME (EQN ("", dummyT, dname)), module, Pretty.string_of (Pretty.blk (0, 

12447  112 
separate Pretty.fbrk fundef @ [Pretty.str ";"])) ^ "\n\n")); 
113 

114 
in 

17144  115 
(case try (get_node gr) dname of 
15531  116 
NONE => 
12447  117 
let 
17144  118 
val gr1 = add_edge (dname, dep) 
119 
(new_node (dname, (SOME (EQN (s, T, "")), module, "")) gr); 

120 
val (gr2, fundef) = mk_fundef module "" "fun " gr1 eqs'; 

12447  121 
val xs = cycle gr2 ([], dname); 
17144  122 
val cs = map (fn x => case get_node gr2 x of 
16645  123 
(SOME (EQN (s, T, _)), _, _) => (s, T) 
12447  124 
 _ => error ("RecfunCodegen: illegal cyclic dependencies:\n" ^ 
125 
implode (separate ", " xs))) xs 

126 
in (case xs of 

17144  127 
[_] => (put_code module fundef gr2, module) 
12447  128 
 _ => 
129 
if not (dep mem xs) then 

130 
let 

16645  131 
val thmss as (_, thyname) :: _ = map (get_equations thy defs) cs; 
17144  132 
val module' = if_library thyname module; 
16645  133 
val eqs'' = map (dest_eq o prop_of) (List.concat (map fst thmss)); 
17144  134 
val (gr3, fundef') = mk_fundef module' "" "fun " 
135 
(add_edge (dname, dep) 

136 
(foldr (uncurry new_node) (del_nodes xs gr2) 

15574
b1d1b5bfc464
Removed practically all references to Library.foldr.
skalberg
parents:
15570
diff
changeset

137 
(map (fn k => 
17144  138 
(k, (SOME (EQN ("", dummyT, dname)), module', ""))) xs))) eqs'' 
139 
in (put_code module' fundef' gr3, module') end 

140 
else (gr2, module)) 

12447  141 
end 
17144  142 
 SOME (SOME (EQN (_, _, s)), module', _) => 
143 
(if s = "" then 

144 
if dname = dep then gr else add_edge (dname, dep) gr 

145 
else if s = dep then gr else add_edge (s, dep) gr, 

146 
module')) 

12447  147 
end; 
148 

17144  149 
fun recfun_codegen thy defs gr dep module brack t = (case strip_comb t of 
16645  150 
(Const (p as (s, T)), ts) => (case (get_equations thy defs p, get_assoc_code thy s T) of 
151 
(([], _), _) => NONE 

15531  152 
 (_, SOME _) => NONE 
17144  153 
 ((eqns, thyname), NONE) => 
16645  154 
let 
17144  155 
val module' = if_library thyname module; 
16645  156 
val (gr', ps) = foldl_map 
17144  157 
(invoke_codegen thy defs dep module true) (gr, ts); 
158 
val suffix = mk_suffix thy defs p; 

159 
val (gr'', module'') = 

160 
add_rec_funs thy defs gr' dep (map prop_of eqns) module'; 

161 
val (gr''', fname) = mk_const_id module'' (s ^ suffix) gr'' 

12447  162 
in 
17144  163 
SOME (gr''', mk_app brack (Pretty.str (mk_qual_id module fname)) ps) 
12447  164 
end) 
15531  165 
 _ => NONE); 
12447  166 

167 

168 
val setup = 

12556  169 
[CodegenData.init, 
12447  170 
add_codegen "recfun" recfun_codegen, 
16645  171 
add_attribute "" 
172 
( Args.del  Scan.succeed del 

173 
 Scan.option (Args.$$$ "target"  Args.colon  Args.name) >> add)]; 

12447  174 

175 
end; 