Accept soft modifiers separated by blank lines

[nicolasstucki]

See scala/scala3#14959

[Jentsch]

I don't think this can be accomplished correctly using tmlanguage.

From the spec:

Note that the regular expressions are matched against only a single line of the document at a time. That means it is not possible to use a pattern that matches multiple lines. [...]

The only way around that is to use a begin and end rule, but can't count the lines or see what's in between begin and end. Which prevents us from disquishing between this two cases:

// Should be highlighted  
transparent
inline def f2 = 2

// Should be not highlighted, because of the is empty line
transparent

inline def f3 = 3

(Shorted test case from scala/scala3#14959)

With this limitation in mind I see two options:

• Always color soft keywords as keywords regardless if they are actually keywords
• Only color soft keywords, if they are on the same line (current behaviour)

Out of those two option I think the current behaviour is the better one and those this issue can be closed as wont-fix.

[tgodzik]

Thanks for investigating! Semantic highlighting in scalameta/metals will also be able to help in this case