scala-ts-mode properly recognizes line comments as comment syntax

[KarlJoad]

This lets Emacs recognize // line comment as proper comment syntax, rather than just unformatted text. The behavior of /* block comments */ is unchanged.

These syntax-table entries are the same as java-ts-mode's, since both languages use the same comment syntax.

Closes #17.

[KaranAhlawat]

I think it would be good to check the syntax table we have here with https://github.com/hvesalai/emacs-scala-mode and see if we're doing the correct thing for comments. If the two are same for comments, please let me know and I'll merge. Otherwise please fix any discrepencies. Thanks for your contribution!

[KarlJoad]

I just checked, and it looks like emacs-scala-mode uses the exact same thing as Java's. I omitted the carriage return character though. I will add that and push.

• Emacs' built-in C/C++/Java modes: https://github.com/emacs-mirror/emacs/blob/d277123f4bf855f0d055d283a42166f123fa1fde/lisp/progmodes/cc-langs.el#L360-L369
• Emacs' built-in java-ts-mode: https://github.com/emacs-mirror/emacs/blob/d277123f4bf855f0d055d283a42166f123fa1fde/lisp/progmodes/java-ts-mode.el#L66-L69
• Scala-mode (No TS): https://github.com/hvesalai/emacs-scala-mode/blob/bd0638c32ab0f2eadacf2809329abf5388211760/scala-mode-syntax.el#L494-L499

[KaranAhlawat]

It also looks like scala-mode (no TS) allows for nested multi-line comments, here , could you take a look at that?

[KarlJoad]

From just a quick test, this change (without n) also handled nested multi-line comments.

sealed trait Test {
  // TODO: This is a quick note
  // Another
  /* The start of a large comment block.
   * Now inside of the comment block, we nest another comment.
   * /* The nested comment that is also
   *  * multi-line! */
   * */
  def foo(): Unit = {}
}

Placing point anywhere inside of the comment block, including inside the nested one, and running the following command: M-: (nth 8 (syntax-ppss)) returns non-nil, which means Emacs understands the contents as comments. If you run that same command on the def keyword, you will get nil back.

I can add n, sure.

Not even Emacs' built-in java-ts-mode does not use n, so I am not sure how important it really is.
https://github.com/emacs-mirror/emacs/blob/2847106f3b6174f25ab43551f96612209fe951c8/lisp/progmodes/java-ts-mode.el#L66-L69

[KaranAhlawat]

Alright, everything looks good to me. Thank you for your patience and contribution!