Constrained primitive types

[JohannesMeierSE]

Examples are:

• strings with restricted length, regular expressions (type inference for concatenation of restricted strings)
• min/max / ranges for numbers (type inference for addition of ranges: <range> + <range>)
• physical units

Requirements:

• Assignability/sub-type rules depend on the current DSL!
• Provide general mechanism / API for "arbitrary" constrainted primitives
• Maybe provide some defaults?
• Maybe support additional properties (not generics Generics #26!) for types, which are not relevant for assignability/validation, but for code generation, e.g. UTF-8 encoding for strings?
• Default behaviour of new parameters is empty, add more behaviour if required by explicit API calls for e.g. assignability, inference
• Maybe these issues target not only primitive types, but any kinds of types?