CODEWITHSUNDEEP
emacselispsyntax-highlighting
simonbs
simonbs

Reputation: 8042

Single and multiline comments in emacs mode using syntax table

I am trying to create an emacs syntax highlighting for a language in which the comments are written as

; A single line comment

;; This comment has
   multipline lines ;;

To do this I need to modify the entries in the syntax table. I have found that the following works perfectly for comments on multiple lines:

(modify-syntax-entry ?\; ". 1234" sbgl-mode-syntax-table)

And the following works perfectly for single line comments:

(modify-syntax-entry ?\; "< b" sbgl-mode-syntax-table)
(modify-syntax-entry ?\n "> b" sbgl-mode-syntax-table)

Does anybody know of a way to combine these?

Upvotes: 3

Views: 965

Answers (2)

immerrr
immerrr

Reputation: 1273

If you can survive adding a space after each semicolon starting a single-line comment, you can treat it as an second character for one of the comment-start sequences and then here's a snippet that works for me:

(define-derived-mode sbgl-mode prog-mode "sbgl"
  (set (make-local-variable 'font-lock-defaults)
       '(nil ;; keywords
         nil ;; keywords-only
         nil ;; case-fold
         ((?\; . ". 1234b")
          (?\n . ">")
          (?\  . "- 2")))))

If not, then you always have an option to do the syntactic analysis prior to fontification via syntax-propertize-function variable (or font-lock-syntactic-keywords variable for pre-Emacs24).

Upvotes: 2

Stefan
Stefan

Reputation: 28531

You can try something like:

(modify-syntax-entry ?\; "< 1234b" sbgl-mode-syntax-table)
(modify-syntax-entry ?\n ">" sbgl-mode-syntax-table)

Upvotes: 0

Related Questions