Grammar improvements: validations, optional semicolons, entry rules

[spoenemann]

• Adds missing validations and fixes [Grammar] Implement additional grammar validations #119.
• Makes semicolons optional. Note: for parser rules and composite rules, a semicolon is still needed if another parser rule follows after that because it starts with an ID. Maybe we can improve the lookahead for this specific case later.
• Consistently call grammar interface fields "fields" instead of "properties" in error messages.
• Added: New entry keyword to explicitly mark the grammar's entry rule

[msujew]

Makes semicolons optional. Note: for parser rules and composite rules, a semicolon is still needed if another parser rule follows after that because it starts with an ID. Maybe we can improve the lookahead for this specific case later.

You can change the decision for that to use LL instead of SLL. That way, it will parse correctly (at the cost of a bit of performance).

[spoenemann]

Makes semicolons optional. Note: for parser rules and composite rules, a semicolon is still needed if another parser rule follows after that because it starts with an ID. Maybe we can improve the lookahead for this specific case later.

You can change the decision for that to use LL instead of SLL. That way, it will parse correctly (at the cost of a bit of performance).

Ok like this?

[msujew]

Ok like this?

I originally had something different in mind - but that doesn't seem to work correctly (for some reason). Your solution works well 👍

[msujew]

Thanks, that helps a lot. Just one comment - also I want some feedback for the optional ; at the end of rules. @cdietrich care to chime in? WDYT?