//should be no instance mcus after generate import own. They should have been replaced already
//(similar to making sure that an variable with an abstract type is assigned to a
//concrete instance 
aspect CheckNoModuleInterfaceInstance {
	public void ASTNode.checkNoModuleInterfaceInstance() {}
	public void ModuleCompilationUnit.checkNoModuleInterfaceInstance() {
		if (isModuleInterface() && isInstance()) {
			String importString = "";
			boolean first = true;
			for (ModuleCompilationUnit mcu : getInstanceContext()) {
				if (!first) { 
					importString += ", ";
				}
				importString += mcu.getBaseCU().getModuleName();
				first = false;	
			}
			String msg = "Module interface " + getBaseCU().getModuleName() + " used in modules " + importString + " is an interface and was not replaced with a non-interface module.";
			getModuleDecl().error(msg);
		}
	}
}