(* Title: HOL/Bali/Type.thy
Author: David von Oheimb
*)
subsection \<open>Java types\<close>
theory Type imports Name begin
text \<open>
simplifications:
\begin{itemize}
\item only the most important primitive types
\item the null type is regarded as reference type
\end{itemize}
\<close>
datatype prim_ty \<comment>\<open>primitive type, cf. 4.2\<close>
= Void \<comment>\<open>result type of void methods\<close>
| Boolean
| Integer
datatype ref_ty \<comment>\<open>reference type, cf. 4.3\<close>
= NullT \<comment>\<open>null type, cf. 4.1\<close>
| IfaceT qtname \<comment>\<open>interface type\<close>
| ClassT qtname \<comment>\<open>class type\<close>
| ArrayT ty \<comment>\<open>array type\<close>
and ty \<comment>\<open>any type, cf. 4.1\<close>
= PrimT prim_ty \<comment>\<open>primitive type\<close>
| RefT ref_ty \<comment>\<open>reference type\<close>
abbreviation "NT == RefT NullT"
abbreviation "Iface I == RefT (IfaceT I)"
abbreviation "Class C == RefT (ClassT C)"
abbreviation Array :: "ty \<Rightarrow> ty" ("_.[]" [90] 90)
where "T.[] == RefT (ArrayT T)"
definition
the_Class :: "ty \<Rightarrow> qtname"
where "the_Class T = (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