TFL/thry.sml
author paulson
Tue May 20 11:49:57 1997 +0200 (1997-05-20)
changeset 3245 241838c01caf
parent 3191 14bd6e5985f1
child 3302 404fe31fd8d2
permissions -rw-r--r--
Removal of redundant code (unused or already present in Isabelle.
This eliminates HOL compatibility but makes the code smaller and more
readable
     1 structure Thry : Thry_sig (* LThry_sig *) = 
     2 struct
     3 
     4 structure USyntax  = USyntax;
     5 
     6 open Mask;
     7 structure S = USyntax;
     8 
     9 
    10 fun THRY_ERR{func,mesg} = Utils.ERR{module = "Thry",func=func,mesg=mesg};
    11 
    12 (*---------------------------------------------------------------------------
    13  *    Matching 
    14  *---------------------------------------------------------------------------*)
    15 
    16 local open Utils
    17       infix 3 |->
    18       fun tybind (x,y) = TVar (x,["term"])  |-> y
    19       fun tmbind (x,y) = Var  (x,type_of y) |-> y
    20 in
    21  fun match_term thry pat ob = 
    22     let val tsig = #tsig(Sign.rep_sg(sign_of thry))
    23         val (ty_theta,tm_theta) = Pattern.match tsig (pat,ob)
    24     in (map tmbind tm_theta, map tybind ty_theta)
    25     end
    26 
    27  fun match_type thry pat ob = 
    28     map tybind(Type.typ_match (#tsig(Sign.rep_sg(sign_of thry))) ([],(pat,ob)))
    29 end;
    30 
    31 
    32 (*---------------------------------------------------------------------------
    33  * Typing 
    34  *---------------------------------------------------------------------------*)
    35 
    36 fun typecheck thry = cterm_of (sign_of thry);
    37 
    38 
    39 
    40 (*----------------------------------------------------------------------------
    41  * Making a definition. The argument "tm" looks like "f = WFREC R M". This 
    42  * entrypoint is specialized for interactive use, since it closes the theory
    43  * after making the definition. This allows later interactive definitions to
    44  * refer to previous ones. The name for the new theory is automatically 
    45  * generated from the name of the argument theory.
    46  *---------------------------------------------------------------------------*)
    47 
    48 
    49 (*---------------------------------------------------------------------------
    50  * TFL attempts to make definitions where the lhs is a variable. Isabelle
    51  * wants it to be a constant, so here we map it to a constant. Moreover, the
    52  * theory should already have the constant, so we refrain from adding the
    53  * constant to the theory. We just add the axiom and return the theory.
    54  *---------------------------------------------------------------------------*)
    55 local val (imp $ tprop $ (eeq $ _ $ _ )) = #prop(rep_thm(eq_reflection))
    56       val Const(eeq_name, ty) = eeq
    57       val prop = #2 (S.strip_type ty)
    58 in
    59 fun make_definition parent s tm = 
    60    let val {lhs,rhs} = S.dest_eq tm
    61        val {Name,Ty} = S.dest_var lhs
    62        val lhs1 = S.mk_const{Name = Name, Ty = Ty}
    63        val eeq1 = S.mk_const{Name = eeq_name, Ty = Ty --> Ty --> prop}
    64        val dtm = list_comb(eeq1,[lhs1,rhs])      (* Rename "=" to "==" *)
    65        val (_, tm', _) = Sign.infer_types (sign_of parent)
    66                      (K None) (K None) [] true ([dtm],propT)
    67        val new_thy = add_defs_i [(s,tm')] parent
    68    in 
    69    (freezeT((get_axiom new_thy s) RS meta_eq_to_obj_eq), new_thy)
    70    end;
    71 end;
    72 
    73 (*---------------------------------------------------------------------------
    74  * Utility routine. Insert into list ordered by the key (a string). If two 
    75  * keys are equal, the new element replaces the old. A more efficient option 
    76  * for the future is needed. In fact, having the list of datatype facts be 
    77  * ordered is useless, since the lookup should never fail!
    78  *---------------------------------------------------------------------------*)
    79 fun insert (el as (x:string, _)) = 
    80  let fun canfind[] = [el] 
    81        | canfind(alist as ((y as (k,_))::rst)) = 
    82            if (x<k) then el::alist
    83            else if (x=k) then el::rst
    84            else y::canfind rst 
    85  in canfind
    86  end;
    87 
    88 
    89 (*---------------------------------------------------------------------------
    90  *     A collection of facts about datatypes
    91  *---------------------------------------------------------------------------*)
    92 val nat_record = Dtype.build_record (Nat.thy, ("nat",["0","Suc"]), nat_ind_tac)
    93 val prod_record =
    94     let val prod_case_thms = Dtype.case_thms (sign_of Prod.thy) [split] 
    95                                  (fn s => res_inst_tac [("p",s)] PairE_lemma)
    96          fun const s = Const(s, the(Sign.const_type (sign_of Prod.thy) s))
    97      in ("*", 
    98          {constructors = [const "Pair"],
    99             case_const = const "split",
   100          case_rewrites = [split RS eq_reflection],
   101              case_cong = #case_cong prod_case_thms,
   102               nchotomy = #nchotomy prod_case_thms}) 
   103      end;
   104 
   105 (*---------------------------------------------------------------------------
   106  * Hacks to make interactive mode work. Referring to "datatypes" directly
   107  * is temporary, I hope!
   108  *---------------------------------------------------------------------------*)
   109 val match_info = fn thy =>
   110     fn "*" => Some({case_const = #case_const (#2 prod_record),
   111                      constructors = #constructors (#2 prod_record)})
   112      | "nat" => Some({case_const = #case_const (#2 nat_record),
   113                        constructors = #constructors (#2 nat_record)})
   114      | ty => case assoc(!datatypes,ty)
   115                of None => None
   116                 | Some{case_const,constructors, ...} =>
   117                    Some{case_const=case_const, constructors=constructors}
   118 
   119 val induct_info = fn thy =>
   120     fn "*" => Some({nchotomy = #nchotomy (#2 prod_record),
   121                      constructors = #constructors (#2 prod_record)})
   122      | "nat" => Some({nchotomy = #nchotomy (#2 nat_record),
   123                        constructors = #constructors (#2 nat_record)})
   124      | ty => case assoc(!datatypes,ty)
   125                of None => None
   126                 | Some{nchotomy,constructors, ...} =>
   127                   Some{nchotomy=nchotomy, constructors=constructors}
   128 
   129 val extract_info = fn thy => 
   130  let val case_congs = map (#case_cong o #2) (!datatypes)
   131          val case_rewrites = flat(map (#case_rewrites o #2) (!datatypes))
   132  in {case_congs = #case_cong (#2 prod_record)::
   133                   #case_cong (#2 nat_record)::case_congs,
   134      case_rewrites = #case_rewrites(#2 prod_record)@
   135                      #case_rewrites(#2 nat_record)@case_rewrites}
   136  end;
   137 
   138 end; (* Thry *)