Function: ruby-calculate-indent

ruby-calculate-indent is a byte-compiled function defined in ruby-mode.el.gz.

Signature

(ruby-calculate-indent &optional PARSE-START)

Documentation

Return the proper indentation level of the current line.

Source Code

;; Defined in /usr/src/emacs/lisp/progmodes/ruby-mode.el.gz
(defun ruby-calculate-indent (&optional parse-start)
  "Return the proper indentation level of the current line."
  ;; TODO: Document body
  (save-excursion
    (beginning-of-line)
    (let ((ruby-indent-point (point))
          (case-fold-search nil)
          state eol begin op-end
          (paren (progn (skip-syntax-forward " ")
                        (and (char-after) (matching-paren (char-after)))))
          (indent 0))
      (if parse-start
          (goto-char parse-start)
        (ruby-beginning-of-indent)
        (setq parse-start (point)))
      (back-to-indentation)
      (setq indent (current-column))
      (setq state (ruby-parse-region parse-start ruby-indent-point))
      (cond
       ((nth 0 state)                   ; within string
        (setq indent nil))              ;  do nothing
       ((car (nth 1 state))             ; in paren
        (goto-char (setq begin (cdr (nth 1 state))))
        (let ((deep (ruby-deep-indent-paren-p (car (nth 1 state)))))
          (if deep
              (cond ((and (eq deep t) (eq (car (nth 1 state)) paren))
                     (skip-syntax-backward " ")
                     (setq indent (1- (current-column))))
                    ((let ((s (ruby-parse-region (point) ruby-indent-point)))
                       (and (nth 2 s) (> (nth 2 s) 0)
                            (or (goto-char (cdr (nth 1 s))) t)))
                     (forward-word-strictly -1)
                     (setq indent (ruby-indent-size (current-column)
						    (nth 2 state))))
                    (t
                     (setq indent (current-column))
                     (cond ((eq deep 'space))
                           (paren (setq indent (1- indent)))
                           (t (setq indent (ruby-indent-size (1- indent) 1))))))
            (if (nth 3 state) (goto-char (nth 3 state))
              (goto-char parse-start) (back-to-indentation))
            (setq indent (ruby-indent-size (current-column) (nth 2 state))))
          (and (eq (car (nth 1 state)) paren)
               (ruby-deep-indent-paren-p (matching-paren paren))
               (search-backward (char-to-string paren))
               (setq indent (current-column)))))
       ((and (nth 2 state) (> (nth 2 state) 0)) ; in nest
        (if (null (cdr (nth 1 state)))
            (error "Invalid nesting"))
        (goto-char (cdr (nth 1 state)))
        (forward-word-strictly -1)               ; skip back a keyword
        (setq begin (point))
        (cond
         ((looking-at "do\\>[^_]")      ; iter block is a special case
          (if (nth 3 state) (goto-char (nth 3 state))
            (goto-char parse-start) (back-to-indentation))
          (setq indent (ruby-indent-size (current-column) (nth 2 state))))
         (t
          (setq indent (+ (current-column) ruby-indent-level)))))

       ((and (nth 2 state) (< (nth 2 state) 0)) ; in negative nest
        (setq indent (ruby-indent-size (current-column) (nth 2 state)))))
      (when indent
        (goto-char ruby-indent-point)
        (end-of-line)
        (setq eol (point))
        (beginning-of-line)
        (cond
         ((and (not (ruby-deep-indent-paren-p paren))
               (re-search-forward ruby-negative eol t))
          (and (not (eq ?_ (char-after (match-end 0))))
               (setq indent (- indent ruby-indent-level))))
         ((and
           (save-excursion
             (beginning-of-line)
             (not (bobp)))
           (or (ruby-deep-indent-paren-p t)
               (null (car (nth 1 state)))))
          ;; goto beginning of non-empty no-comment line
          (let (end done)
            (while (not done)
              (skip-chars-backward " \t\n")
              (setq end (point))
              (beginning-of-line)
              (if (re-search-forward "^\\s *#" end t)
                  (beginning-of-line)
                (setq done t))))
          (end-of-line)
          ;; skip the comment at the end
          (skip-chars-backward " \t")
          (let (end (pos (point)))
            (beginning-of-line)
            (while (and (re-search-forward "#" pos t)
                        (setq end (1- (point)))
                        (or (ruby-special-char-p end)
                            (and (setq state (ruby-parse-region
                                              parse-start end))
                                 (nth 0 state))))
              (setq end nil))
            (goto-char (or end pos))
            (skip-chars-backward " \t")
            (setq begin (if (and end (nth 0 state)) pos (cdr (nth 1 state))))
            (setq state (ruby-parse-region parse-start (point))))
          (or (bobp) (forward-char -1))
          (and
           (or (and (looking-at ruby-symbol-re)
                    (skip-chars-backward ruby-symbol-chars)
                    (looking-at (concat "\\<\\(" ruby-block-hanging-re
                                        "\\)\\>"))
                    (not (eq (point) (nth 3 state)))
                    (save-excursion
                      (goto-char (match-end 0))
                      (not (looking-at "[a-z_]"))))
               (and (looking-at ruby-operator-re)
                    (not (ruby-special-char-p))
                    (save-excursion
                      (forward-char -1)
                      (or (not (looking-at ruby-operator-re))
                          (not (eq (char-before) ?:))))
                    ;; Operator at the end of line.
                    (let ((c (char-after (point))))
                      (and
;;                     (or (null begin)
;;                         (save-excursion
;;                           (goto-char begin)
;;                           (skip-chars-forward " \t")
;;                           (not (or (eolp) (looking-at "#")
;;                                    (and (eq (car (nth 1 state)) ?{)
;;                                         (looking-at "|"))))))
                       ;; Not a regexp or percent literal.
                       (null (nth 0 (ruby-parse-region (or begin parse-start)
                                                       (point))))
                       (or (not (eq ?| (char-after (point))))
                           (save-excursion
                             (or (eolp) (forward-char -1))
                             (cond
                              ((search-backward "|" nil t)
                               (skip-chars-backward " \t\n")
                               (and (not (eolp))
                                    (progn
                                      (forward-char -1)
                                      (not (looking-at "{")))
                                    (progn
                                      (forward-word-strictly -1)
                                      (not (looking-at "do\\>[^_]")))))
                              (t t))))
                       (not (eq ?, c))
                       (setq op-end t)))))
           (setq indent
                 (cond
                  ((and
                    (null op-end)
                    (not (looking-at (concat "\\<\\(" ruby-block-hanging-re
                                             "\\)\\>")))
                    (eq (ruby-deep-indent-paren-p t) 'space)
                    (not (bobp)))
                   (goto-char (or begin parse-start))
                   (skip-syntax-forward " ")
                   (current-column))
                  ((car (nth 1 state)) indent)
                  (t
                   (+ indent ruby-indent-level))))))))
      (goto-char ruby-indent-point)
      (beginning-of-line)
      (skip-syntax-forward " ")
      (if (looking-at "\\.[^.]\\|&\\.")
          (+ indent ruby-indent-level)
        indent))))