src/CCL/term.thy
changeset 13894 8018173a7979
parent 13893 19849d258890
child 13895 b6105462ccd3
equal deleted inserted replaced
13893:19849d258890 13894:8018173a7979
     1 (*  Title: 	CCL/terms.thy
       
     2     ID:         $Id$
       
     3     Author: 	Martin Coen
       
     4     Copyright   1993  University of Cambridge
       
     5 
       
     6 Definitions of usual program constructs in CCL.
       
     7 
       
     8 *)
       
     9 
       
    10 Term = CCL +
       
    11 
       
    12 consts
       
    13 
       
    14   one        ::	      "i"
       
    15 
       
    16   if         ::       "[i,i,i]=>i"           ("(3if _/ then _/ else _)" [] 60)
       
    17 
       
    18   inl,inr    ::	      "i=>i"
       
    19   when       ::	      "[i,i=>i,i=>i]=>i" 
       
    20 
       
    21   split      ::	      "[i,[i,i]=>i]=>i"
       
    22   fst,snd,   
       
    23   thd        ::       "i=>i"
       
    24 
       
    25   zero       ::	      "i"
       
    26   succ       ::	      "i=>i"
       
    27   ncase      ::	      "[i,i,i=>i]=>i"
       
    28   nrec       ::	      "[i,i,[i,i]=>i]=>i"
       
    29 
       
    30   nil        ::       "i"                    ("([])")
       
    31   "$"        ::       "[i,i]=>i"             (infixr 80)
       
    32   lcase      ::	      "[i,i,[i,i]=>i]=>i"
       
    33   lrec       ::	      "[i,i,[i,i,i]=>i]=>i"
       
    34 
       
    35   let        ::       "[i,i=>i]=>i"
       
    36   letrec     ::       "[[i,i=>i]=>i,(i=>i)=>i]=>i"
       
    37   letrec2    ::       "[[i,i,i=>i=>i]=>i,(i=>i=>i)=>i]=>i"
       
    38   letrec3    ::       "[[i,i,i,i=>i=>i=>i]=>i,(i=>i=>i=>i)=>i]=>i"  
       
    39 
       
    40   "@let"     ::       "[id,i,i]=>i"             ("(3let _ be _/ in _)" [] 60)
       
    41   "@letrec"  ::       "[id,id,i,i]=>i"          ("(3letrec _ _ be _/ in _)"  [] 60)
       
    42   "@letrec2" ::       "[id,id,id,i,i]=>i"       ("(3letrec _ _ _ be _/ in _)"  [] 60)
       
    43   "@letrec3" ::       "[id,id,id,id,i,i]=>i"    ("(3letrec _ _ _ _ be _/ in _)"  [] 60)
       
    44 
       
    45   napply    :: "[i=>i,i,i]=>i"      ("(_ ^ _ ` _)")
       
    46 
       
    47 rules
       
    48 
       
    49   one_def                    "one == true"
       
    50   if_def     "if b then t else u  == case(b,t,u,% x y.bot,%v.bot)"
       
    51   inl_def                 "inl(a) == <true,a>"
       
    52   inr_def                 "inr(b) == <false,b>"
       
    53   when_def           "when(t,f,g) == split(t,%b x.if b then f(x) else g(x))"
       
    54   split_def           "split(t,f) == case(t,bot,bot,f,%u.bot)"
       
    55   fst_def                 "fst(t) == split(t,%x y.x)"
       
    56   snd_def                 "snd(t) == split(t,%x y.y)"
       
    57   thd_def                 "thd(t) == split(t,%x p.split(p,%y z.z))"
       
    58   zero_def                  "zero == inl(one)"
       
    59   succ_def               "succ(n) == inr(n)"
       
    60   ncase_def         "ncase(n,b,c) == when(n,%x.b,%y.c(y))"
       
    61   nrec_def          " nrec(n,b,c) == letrec g x be ncase(x,b,%y.c(y,g(y))) in g(n)"
       
    62   nil_def	              "[] == inl(one)"
       
    63   cons_def                   "h$t == inr(<h,t>)"
       
    64   lcase_def         "lcase(l,b,c) == when(l,%x.b,%y.split(y,c))"
       
    65   lrec_def           "lrec(l,b,c) == letrec g x be lcase(x,b,%h t.c(h,t,g(t))) in g(l)"
       
    66 
       
    67   let_def  "let x be t in f(x) == case(t,f(true),f(false),%x y.f(<x,y>),%u.f(lam x.u(x)))"
       
    68   letrec_def    
       
    69   "letrec g x be h(x,g) in b(g) == b(%x.fix(%f.lam x.h(x,%y.f`y))`x)"
       
    70 
       
    71   letrec2_def  "letrec g x y be h(x,y,g) in f(g)== \
       
    72 \               letrec g' p be split(p,%x y.h(x,y,%u v.g'(<u,v>))) \
       
    73 \                          in f(%x y.g'(<x,y>))"
       
    74 
       
    75   letrec3_def  "letrec g x y z be h(x,y,z,g) in f(g) == \
       
    76 \             letrec g' p be split(p,%x xs.split(xs,%y z.h(x,y,z,%u v w.g'(<u,<v,w>>)))) \
       
    77 \                          in f(%x y z.g'(<x,<y,z>>))"
       
    78 
       
    79   napply_def "f ^n` a == nrec(n,a,%x g.f(g))"
       
    80 
       
    81 end
       
    82 
       
    83 ML
       
    84 
       
    85 (** Quantifier translations: variable binding **)
       
    86 
       
    87 fun let_tr [Free(id,T),a,b] = Const("let",dummyT) $ a $ absfree(id,T,b);
       
    88 fun let_tr' [a,Abs(id,T,b)] =
       
    89      let val (id',b') = variant_abs(id,T,b)
       
    90      in Const("@let",dummyT) $ Free(id',T) $ a $ b' end;
       
    91 
       
    92 fun letrec_tr [Free(f,S),Free(x,T),a,b] = 
       
    93       Const("letrec",dummyT) $ absfree(x,T,absfree(f,S,a)) $ absfree(f,S,b);
       
    94 fun letrec2_tr [Free(f,S),Free(x,T),Free(y,U),a,b] = 
       
    95       Const("letrec2",dummyT) $ absfree(x,T,absfree(y,U,absfree(f,S,a))) $ absfree(f,S,b);
       
    96 fun letrec3_tr [Free(f,S),Free(x,T),Free(y,U),Free(z,V),a,b] = 
       
    97       Const("letrec3",dummyT) $ absfree(x,T,absfree(y,U,absfree(z,U,absfree(f,S,a)))) $ absfree(f,S,b);
       
    98 
       
    99 fun letrec_tr' [Abs(x,T,Abs(f,S,a)),Abs(ff,SS,b)] =
       
   100      let val (f',b')  = variant_abs(ff,SS,b)
       
   101          val (_,a'') = variant_abs(f,S,a)
       
   102          val (x',a')  = variant_abs(x,T,a'')
       
   103      in Const("@letrec",dummyT) $ Free(f',SS) $ Free(x',T) $ a' $ b' end;
       
   104 fun letrec2_tr' [Abs(x,T,Abs(y,U,Abs(f,S,a))),Abs(ff,SS,b)] =
       
   105      let val (f',b') = variant_abs(ff,SS,b)
       
   106          val ( _,a1) = variant_abs(f,S,a)
       
   107          val (y',a2) = variant_abs(y,U,a1)
       
   108          val (x',a') = variant_abs(x,T,a2)
       
   109      in Const("@letrec2",dummyT) $ Free(f',SS) $ Free(x',T) $ Free(y',U) $ a' $ b'
       
   110       end;
       
   111 fun letrec3_tr' [Abs(x,T,Abs(y,U,Abs(z,V,Abs(f,S,a)))),Abs(ff,SS,b)] =
       
   112      let val (f',b') = variant_abs(ff,SS,b)
       
   113          val ( _,a1) = variant_abs(f,S,a)
       
   114          val (z',a2) = variant_abs(z,V,a1)
       
   115          val (y',a3) = variant_abs(y,U,a2)
       
   116          val (x',a') = variant_abs(x,T,a3)
       
   117      in Const("@letrec3",dummyT) $ Free(f',SS) $ Free(x',T) $ Free(y',U) $ Free(z',V) $ a' $ b'
       
   118       end;
       
   119 
       
   120 val  parse_translation=
       
   121     [("@let",       let_tr),
       
   122      ("@letrec",    letrec_tr),
       
   123      ("@letrec2",   letrec2_tr),
       
   124      ("@letrec3",   letrec3_tr)
       
   125     ];
       
   126 val print_translation=
       
   127     [("let",       let_tr'),
       
   128      ("letrec",    letrec_tr'),
       
   129      ("letrec2",   letrec2_tr'),
       
   130      ("letrec3",   letrec3_tr')
       
   131     ];