Type instance and sub-super relationship « Topincs Issues

Issue description

The type-instance relationship has a special relation to the sub-super relationship. Subtypes are instances of the same type as the their supertypes. E.g. in the TMCL schema.ctm constraint is a topic type. Abstract constraint is a kind of constraint. It follows that abstract constraint is a topic type, altough their is no explicit statement mentioning this.

Comment

Generally i can think of two ways to implement this: * Make the conclusion an explicit type-instance statement * Avoid the explicit statement, but make it look like the statement holds in the application code

I chose to avoid to persist the conclusion and generally did tie all loose ends. I did make the type member of TopicProxy respect the rule and creates a method TypeInstance::get_instances which does also respect the rule.

It turns out that this was a logical error in the schema.ctm of the draft dated 2009-10-29.

Reporting date

2010-01-28+01:00

Resolving date

2010-01-29+01:00

Planned for version

Topincs 4.0.0 (Product version)

Realized through

Work session 253 (Work session)

Work session 254 (Work session)

Reported by

Robert Cerny (Person)

Resolved by