static public Object maybeResolveIn(Namespace n, Symbol sym) throws Exception{
	//note - ns-qualified vars must already exist
	if(sym.ns != null)
		{
		Namespace ns = namespaceFor(n, sym);
		if(ns == null)
			return null;
		Var v = ns.findInternedVar(Symbol.intern(sym.name));
		if(v == null)
			return null;
		return v;
		}
	else if(sym.name.indexOf('.') > 0 && !sym.name.endsWith(".") 
			|| sym.name.charAt(0) == '[')
		{
		return RT.classForName(sym.name);
		}
	else if(sym.equals(NS))
			return RT.NS_VAR;
		else if(sym.equals(IN_NS))
				return RT.IN_NS_VAR;
			else
				{
				Object o = n.getMapping(sym);
				return o;
				}
}