public override Cmd VisitRE(RE node) {
//Contract.Requires(node != null);
Contract.Ensures(Contract.Result<Cmd>() != null);
return base.VisitRE((RE)node.Clone());
}
public virtual Cmd VisitRE(RE node) {
Contract.Requires(node != null);
Contract.Ensures(Contract.Result<Cmd>() != null);
return (Cmd)this.Visit(node); // Call general visit so subtypes get visited by their particular visitor
}
public static VCExpr RegExpr(RE r, VCExpr N, VCContext ctxt)
{
Contract.Requires(r != null);
Contract.Requires(N != null);
Contract.Requires(ctxt != null);
Contract.Ensures(Contract.Result<VCExpr>() != null);
if ( r is AtomicRE )
{
AtomicRE ar = (AtomicRE) r;
return Block(ar.b, N, ctxt);
}
else if ( r is Sequential )
{
Sequential s = (Sequential) r;
return RegExpr(s.first, RegExpr(s.second, N, ctxt), ctxt);
}
else if ( r is Choice )
{
Choice ch = (Choice) r;
VCExpr res;
if (ch.rs == null || ch.rs.Count==0)
{
res = N;
}
else
{
VCExpr currentWLP = RegExpr(cce.NonNull(ch.rs[0]), N, ctxt);
for (int i = 1, n = ch.rs.Count; i < n; i++)
{
currentWLP = ctxt.Ctxt.ExprGen.And(currentWLP, RegExpr(cce.NonNull(ch.rs[i]), N, ctxt));
}
res = currentWLP;
}
return res;
}
else
{
Contract.Assert(false);throw new cce.UnreachableException(); // unexpected RE subtype
}
}
public override Cmd VisitRE(RE node)
{
Contract.Ensures(Contract.Result<Cmd>() == node);
return (Cmd)this.Visit(node); // Call general visit so subtypes get visited by their particular visitor
}
public Sequential(RE a, RE b) {
Contract.Requires(b != null);
Contract.Requires(a != null);
first = a;
second = b;
}