emacs-config/utils/al-text.el

;;; al-text.el --- Additional functionality related to text editing

;; Copyright © 2014-2016 Alex Kost

;; This program is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.

;; This program is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with this program.  If not, see <http://www.gnu.org/licenses/>.

;;; Code:

(defun al/beginning-of-buffer ()
  (goto-char (point-min)))

(defun al/show-trailing-whitespace ()
  (setq-local show-trailing-whitespace t))

(defun al/no-truncate-lines ()
  (setq-local truncate-lines nil))

(defun al/inhibit-field-motion ()
  (setq-local inhibit-field-text-motion t))

(defun al/bar-cursor-type ()
  (setq-local cursor-type 'bar))

(defun al/hbar-cursor-type ()
  (setq-local cursor-type 'hbar))

(defun al/no-syntactic-font-lock ()
  (setq-local font-lock-keywords-only t))

(defun al/set-comment-column ()
  (setq-local comment-column 32))

(defmacro al/modify-syntax (table-name &rest specs)
  "Update syntax table according to SPECS.
TABLE-NAME is a name (unquoted symbol) of a syntax table variable.
SPECS are (CHAR NEWENTRY) elements.  See `modify-syntax-entry'
for details."
  (declare (indent 1))
  (let ((table-var (make-symbol "table")))
    `(al/with-check
       :var ',table-name
       (let ((,table-var (symbol-value ',table-name)))
         ,@(mapcar
            (lambda (spec)
              (pcase spec
                (`(,char ,entry)
                 `(modify-syntax-entry ,char ,entry ,table-var))))
            specs)))))

(defmacro al/modify-page-break-syntax (table-name)
  "Set non-whitespace syntax for ^L in syntax table TABLE-NAME.
Page break should not belong to whitespace syntax, because
`back-to-indentation' moves the point after ^L character which is not good.
Also it (default syntax) breaks `indent-guide-mode'."
  `(al/modify-syntax ,table-name (?\f ">   ")))

(provide 'al-text)

;;; al-text.el ends here