Typesystem
What is Helgins?
It's the old name of the typesystem. The name is nowadays not used anymore.
Typesystem rules are not executing.
Turn off the power save mode. Also make sure that the languages that contains the rules is used. Make sure that under Tool-> Model Checker the typesystem checks are enabled. Some rules are only checked when "Check model" is invoked. In this case the option "do not apply on the fly" is set to true in a checking rule.
Are comparison rules often used?
No, they are rarely used (not many results across various code bases).
How to I learn more about MPS CodeRules?
This is kind of a new typesystem bases on constraints. Visit the Github page for more information. There is also a blog post about this project. The new MPS implementation of the Kotlin language uses CodeRules. More information can be found on the Github page. There is also a free course about it on stepik.
Typesystem vs constraints?
Specific Languages Blog — Typesystem vs constraints
Subtyping vs inheritance?
Specific Languages Blog — Subtyping vs inheritance
How can I speed up model checks?
Specific Languages Blog — Speeding up model checks with Scope Cache