Interfaces, Views and Violations new syntax proposal

[stefjoosten]

Syntax: boxentry ::= OPTIONAL label ; OPTIONAL ( SYMBOL ':' ; (expression | string) )

Considerations

1. The list of entries is ordered.
2. A missing label is equivalent with an empty label.
3. Each label may be any string. double occurrences are allowed within a box.

This results in the following:

• [ ] Type checker: see the examples where _src is mentioned. This means that some relations can be in scope and of a certain type in certain places, while they are not in scope or of a different type in others. Currently the type checker does not have a scope. This will be discussed in Issue #543
• [ ] Parser: this is a no-brainer; the parser should parse the new syntax. This will be done in several steps, one of which is #544
• [ ] Update test cases and examples: get everything to work in the new syntax