(* Title: HOL/MicroJava/J/WellForm.thy
ID: $Id$
Author: David von Oheimb
Copyright 1999 Technische Universitaet Muenchen
Well-formedness of Java programs
for static checks on expressions and statements, see WellType.thy
improvements over Java Specification 1.0 (cf. 8.4.6.3, 8.4.6.4, 9.4.1):
* a method implementing or overwriting another method may have a result type
that widens to the result type of the other method (instead of identical type)
simplifications:
* for uniformity, Object is assumed to be declared like any other class
*)
WellForm = TypeRel +
types 'c wtm = 'c prog => cname => 'c mdecl => bool
constdefs
wf_fdecl :: "'c prog \\<Rightarrow> fdecl \\<Rightarrow> bool"
"wf_fdecl G \\<equiv> \\<lambda>(fn,ft). is_type G ft"
wf_mhead :: "'c prog \\<Rightarrow> sig \\<Rightarrow> ty \\<Rightarrow> bool"
"wf_mhead G \\<equiv> \\<lambda>(mn,pTs) rT. (\\<forall>T\\<in>set pTs. is_type G T) \\<and> is_type G rT"
wf_mdecl :: "'c wtm \\<Rightarrow> 'c wtm"
"wf_mdecl wtm G C \\<equiv> \\<lambda>(sig,rT,mb). wf_mhead G sig rT \\<and> wtm G C (sig,rT,mb)"
wf_cdecl :: "'c wtm \\<Rightarrow> 'c prog \\<Rightarrow> 'c cdecl \\<Rightarrow> bool"
"wf_cdecl wtm G \\<equiv>
\\<lambda>(C,(sc,fs,ms)).
(\\<forall>f\\<in>set fs. wf_fdecl G f ) \\<and> unique fs \\<and>
(\\<forall>m\\<in>set ms. wf_mdecl wtm G C m) \\<and> unique ms \\<and>
(case sc of None \\<Rightarrow> C = Object
| Some D \\<Rightarrow>
is_class G D \\<and> \\<not> G\\<turnstile>D\\<prec>C C \\<and>
(\\<forall>(sig,rT,b)\\<in>set ms. \\<forall>D' rT' b'.
method(G,D) sig = Some(D',rT',b') \\<longrightarrow> G\\<turnstile>rT\\<preceq>rT'))"
wf_prog :: "'c wtm \\<Rightarrow> 'c prog \\<Rightarrow> bool"
"wf_prog wtm G \\<equiv>
let cs = set G in ObjectC \\<in> cs \\<and> (\\<forall>c\\<in>cs. wf_cdecl wtm G c) \\<and> unique G"
end