public static void Resolve(this expr e, block scope)
{
if (e is constant)
{
return;
}
var v = e as variable;
if (v != null)
{
var d = scope.Lookup(v.id);
v.Untyped.AddAnnotation(
new DeclAnnotation {
reference = d
});
return;
}
var b = e as block;
if (b != null)
{
b.Untyped.AddAnnotation(
new BlockAnnotation {
reference = scope
});
foreach (expr x in b.expr)
{
x.Resolve(b);
}
return;
}
var a = e as assign;
if (a != null)
{
var d = scope.Lookup(a.id);
a.Untyped.AddAnnotation(
new DeclAnnotation {
reference = d
});
a.rhs.Resolve(scope);
return;
}
}
// Look up variables
static decl Lookup(this block scope, string id)
{
decl local =
(from d in scope.decl
where d.id == id
select d).FirstOrDefault();
if (local != null)
{
return(local);
}
block up = null;
try {
up = scope.Untyped.Annotation <BlockAnnotation>().reference;
}
catch (Exception) {
// Undeclared variable
throw new InvalidOperationException();
}
return(up.Lookup(id));
}