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I'm trying to use a regular expression of the form "foo\\(?:\\(bar\\)\\(baz\\)\\)*\\(quux\\)", but I want the inner two subexpressions to retain all of their matches, not just the first one. I realize this may be impossible to achieve as stated, so I'll give more detail about why I want this to work.

My specific case is that I'm trying produce a major mode for editing and highlighting Dwarf Fortress "raw" files. The regular expression I'm having this trouble with is

"\\(\\[\\)\\([_A-Z]+\\)\\(?:\\(:\\)\\([^][:]*\\)\\)*\\(\\]\\)"

, which successfully matches a single complete raw tag with all of its parameters; however, capturing groups 3 and 4 only end up containing the last parameter (after having successfully matched all the previous ones), and therefore all but the last parameter is not highlighted by font-lock. I understand why this is the case, but I'd like to know if there is a way to get around it, or to otherwise enable my desired behavior.

  • 1
    Is "foo\\(?:bar\\|baz\\)*\\(quux\\)" what you want? Note the or-operator \\|. – Tobias Feb 9 '16 at 10:32
  • @Tobias No; I need it to match things of the pattern foo bar baz bar baz … bar baz quux and highlight all the bar baz pairs in between. – Ptharien's Flame Feb 9 '16 at 15:29
2

You can use an anchored font-lock rule. They are used when you want a search within a search. The look like:

(PATTERN
 (SUBPATTERN
  PRE-MATCH-FORM
  POST-MATCH-FORM
  HIGHLIGHT
  ...))

In your case, it could be something like:

(defvar my-raw-rule
  '(("\\["
     ("\\_<\\(\\sw\\|\\s_\\)+\\_>"
      ;; Pre-match form: Limit search to closing "]" or end-of-line.
      (save-excursion
        (if (re-search-forward "\\]" (line-end-position) t)
            (point)
          nil))
      ;; Post-match form
      nil
      (0 font-lock-constant-face)))))

Note that the rule highlights words after the [ even when the ] isn't present -- this is typically what you want when writing code.

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