+(defun sh-quoted-subshell (limit)
+ "Search for a subshell embedded in a string.
+Find all the unescaped \" characters within said subshell, remembering that
+subshells can nest."
+ ;; FIXME: This can (and often does) match multiple lines, yet it makes no
+ ;; effort to handle multiline cases correctly, so it ends up being
+ ;; rather flakey.
+ (when (and (re-search-forward "\"\\(?:\\(?:.\\|\n\\)*?[^\\]\\(?:\\\\\\\\\\)*\\)??\\(\\$(\\|`\\)" limit t)
+ ;; Make sure the " we matched is an opening quote.
+ (eq ?\" (nth 3 (syntax-ppss))))
+ ;; bingo we have a $( or a ` inside a ""
+ (let ((char (char-after (point)))
+ (continue t)
+ (pos (point))
+ (data nil) ;; value to put into match-data (and return)
+ (last nil) ;; last char seen
+ (bq (equal (match-string 1) "`")) ;; ` state flip-flop
+ (seen nil) ;; list of important positions
+ (nest 1)) ;; subshell nesting level
+ (while (and continue char (<= pos limit))
+ ;; unescaped " inside a $( ... ) construct.
+ ;; state machine time...
+ ;; \ => ignore next char;
+ ;; ` => increase or decrease nesting level based on bq flag
+ ;; ) [where nesting > 0] => decrease nesting
+ ;; ( [where nesting > 0] => increase nesting
+ ;; ( [preceeded by $ ] => increase nesting
+ ;; " [nesting <= 0 ] => terminate, we're done.
+ ;; " [nesting > 0 ] => remember this, it's not a proper "
+ ;; FIXME: don't count parens that appear within quotes.
+ (cond
+ ((eq ?\\ last) nil)
+ ((eq ?\` char) (setq nest (+ nest (if bq -1 1)) bq (not bq)))
+ ((and (> nest 0) (eq ?\) char)) (setq nest (1- nest)))
+ ((and (eq ?$ last) (eq ?\( char)) (setq nest (1+ nest)))
+ ((and (> nest 0) (eq ?\( char)) (setq nest (1+ nest)))
+ ((eq char ?\")
+ (if (>= 0 nest) (setq continue nil) (push pos seen))))
+ ;;(message "POS: %d [%d]" pos nest)
+ (setq last char
+ pos (1+ pos)
+ char (char-after pos)) )
+ ;; FIXME: why construct a costly match data to pass to
+ ;; sh-apply-quoted-subshell rather than apply the highlight
+ ;; directly here? -- Stef
+ (when seen
+ ;;(message "SEEN: %S" seen)
+ (setq data (list (current-buffer)))
+ (dolist(P seen)
+ (setq data (cons P (cons (1+ P) data))))
+ (store-match-data data))
+ data) ))
+