Type checks do not cover all objects

The type check is currently initiated by this model procesor (in virtmat.language.constraints.typechecks)

def check_types_processor(model, _):
    """evaluate type of all objects that have type"""
    classes = ['VarTuple', 'Variable', 'Print', 'ConditionIn', 'ConditionComparison']
    for cls in classes:
        for obj in get_children_of_type(cls, model):
            _ = obj.type_

It is implicitly assumed that the objects of these classes call the type_ property for all their children. This may not be the case and is hard to check / fix.

According to the intention "evaluate type of all objects that have type", this may be a better solution:

def check_types_processor(model, metamodel):
    """evaluate type of all objects that have type"""
    classes = []
    for ns_key, ns_val in metamodel.namespaces.items():
        if ns_key != '__base__':
            for cls_name, cls in ns_val.items():
                if getattr(cls, 'type_', False):
                    classes.append(cls_name)
    for cls in classes:
        for obj in get_children_of_type(cls, model):
            _ = obj.type_

Also the processor should be moved to virtmat.language.constraints.processors.