src/HOL/Bali/Type.thy

generalized proof by abstraction,
abstract propositional nnf goals (lets best_tac succeed on very large terms)

(*  Title:      HOL/Bali/Type.thy
    ID:         $Id$
    Author:     David von Oheimb
*)

header {* Java types *}

theory Type imports Name begin

text {*
simplifications:
\begin{itemize}
\item only the most important primitive types
\item the null type is regarded as reference type
\end{itemize}
*}

datatype prim_ty        --{* primitive type, cf. 4.2 *}
        = Void          --{* result type of void methods *}
        | Boolean
        | Integer


datatype ref_ty         --{* reference type, cf. 4.3 *}
        = NullT         --{* null type, cf. 4.1 *}
        | IfaceT qtname --{* interface type *}
        | ClassT qtname --{* class type *}
        | ArrayT ty     --{* array type *}

and ty                  --{* any type, cf. 4.1 *}
        = PrimT prim_ty --{* primitive type *}
        | RefT  ref_ty  --{* reference type *}

translations
  "prim_ty" <= (type) "Type.prim_ty"
  "ref_ty"  <= (type) "Type.ref_ty"
  "ty"      <= (type) "Type.ty"

syntax
         NT     :: "       \<spacespace> ty"
         Iface  :: "qtname  \<Rightarrow> ty"
         Class  :: "qtname  \<Rightarrow> ty"
         Array  :: "ty     \<Rightarrow> ty"    ("_.[]" [90] 90)

translations
        "NT"      == "RefT   NullT"
        "Iface I" == "RefT (IfaceT I)"
        "Class C" == "RefT (ClassT C)"
        "T.[]"    == "RefT (ArrayT T)"

constdefs
  the_Class :: "ty \<Rightarrow> qtname"
 "the_Class T \<equiv> SOME C. T = Class C" (** primrec not possible here **)
 
lemma the_Class_eq [simp]: "the_Class (Class C)= C"
by (auto simp add: the_Class_def)

end