Function: treesit-indent-region

treesit-indent-region is a byte-compiled function defined in treesit.el.gz.

Signature

(treesit-indent-region BEG END)

Documentation

Indent the region between BEG and END.

Similar to treesit-indent, but indent a region instead.

Source Code

;; Defined in /usr/src/emacs/lisp/treesit.el.gz
(defun treesit-indent-region (beg end)
  "Indent the region between BEG and END.
Similar to `treesit-indent', but indent a region instead."
  (when (markerp beg) (setq beg (marker-position beg)))
  (when (markerp end) (setq end (marker-position end)))
  (treesit-update-ranges beg end)
  ;; We indent `treesit--indent-region-batch-size' lines at a time, to
  ;; reduce the number of times the parser needs to re-parse.  In each
  ;; batch, we go through each line and calculate the anchor and
  ;; offset as usual, but instead of modifying the buffer, we save
  ;; these information in a vector.  Once we've collected ANCHOR and
  ;; OFFSET for each line in the batch, we go through each line again
  ;; and apply the changes.  Now that buffer is modified, we need to
  ;; reparse the buffer before continuing to indent the next batch.
  (let* ((meta-len 2)
         (vector-len (* meta-len treesit--indent-region-batch-size))
         ;; This vector saves the indent meta for each line in the
         ;; batch.  It is a vector [ANCHOR OFFSET ANCHOR OFFSET...].
         ;; ANCHOR is a marker on the anchor position, and OFFSET is
         ;; an integer.  ANCHOR and OFFSET are either both nil, or
         ;; both valid.
         (meta-vec (make-vector vector-len 0))
         (lines-left-to-move 0)
         (end (copy-marker end t))
         (idx 0)
         (starting-pos 0)
         (announce-progress (> (- end beg) 80000)))
    (save-excursion
      (goto-char beg)
      ;; First pass.  Go through each line and compute the
      ;; indentation.
      (while (and (eq lines-left-to-move 0) (< (point) end))
        (setq idx 0
              starting-pos (point))
        (while (and (eq lines-left-to-move 0)
                    (< idx treesit--indent-region-batch-size)
                    (< (point) end))
          (if (looking-at (rx (* whitespace) eol) t)
              ;; Unlike in `indent-line' where we sometimes pre-indent
              ;; an empty line, We don't indent empty lines in
              ;; `indent-region'.  Set ANCHOR and OFFSET to nil.
              (setf (aref meta-vec (* idx meta-len)) nil
                    (aref meta-vec (+ 1 (* idx meta-len))) nil)
            (pcase-let* ((`(,anchor . ,offset) (treesit--indent-1))
                         (marker (aref meta-vec (* idx meta-len))))
              (if (not (and anchor offset))
                  ;; No indent for this line, either...
                  (if (markerp marker)
                      (progn
                        ;; ... Set marker and offset to do a dummy
                        ;; indent, or...
                        (back-to-indentation)
                        (move-marker marker (point))
                        (setf (aref meta-vec (+ 1 (* idx meta-len))) 0))
                    ;; ...Set anchor to nil so no indent is performed.
                    (setf (aref meta-vec (* idx meta-len)) nil))
                ;; Set ANCHOR.
                (if (markerp marker)
                    (move-marker marker anchor)
                  (setf (aref meta-vec (* idx meta-len))
                        (copy-marker anchor t)))
                ;; SET OFFSET.
                (setf (aref meta-vec (+ 1 (* idx meta-len))) offset))))
          (incf idx)
          (setq lines-left-to-move (forward-line 1)))
        ;; Now IDX = last valid IDX + 1.
        (goto-char starting-pos)
        ;; Second pass, go to each line and apply the indentation.
        (dotimes (jdx idx)
          (let ((anchor (aref meta-vec (* jdx meta-len)))
                (offset (aref meta-vec (+ 1 (* jdx meta-len)))))
            (when (and anchor offset)
              (let ((col (save-excursion
                           (goto-char anchor)
                           (+ offset (current-column)))))
                (indent-line-to col))))
          (forward-line 1))
        (when announce-progress
          (message "Indenting region...%s%%"
                   (/ (* (- (point) beg) 100) (- end beg)))))
      ;; Delete markers.
      (dotimes (idx treesit--indent-region-batch-size)
        (let ((marker (aref meta-vec (* idx meta-len))))
          (when (markerp marker)
            (move-marker marker nil))))
      (move-marker end nil))))