Xtext grammar file is too large

[SimonCockx]

Currently the whole grammar of Rune is defined in a single huge xtext file. This in turn leads to large derived Java classes, both generated (parser, sequencer, ...) and manually written (validator, formatter, ...).

Splitting up our grammar file can improve modularity, leading to more maintainable code. Additionally, projects using jacoco will stop seeing MethodTooLargeExceptions while building when they have the Rune DSL as a dependency.

I would propose the following splitting:

• Rune types.
• Rune expressions (extends Rune types).
• Rune functions (extends Rune expressions).
• Rune reporting (extends Rune expressions).
• Rune translate (extends Rune expressions).
• Rune (top layer interface, extends everything).

[cdietrich]

You should have a look in the workflow options to split classes eg the parser