preserves/preserves.el

132 lines
5.0 KiB
EmacsLisp

;;; preserves.el --- Preserves editing commands for Emacs
;; Add code like the following to your .emacs to install:
;; (autoload 'preserves-mode "...path.to.wherever.you.put.this.file.../preserves.el" nil t)
;; (setq auto-mode-alist (cons '("\\.mu\\'" . preserves-mode)
;; auto-mode-alist))
;; Copyright (C) 1988,94,96,2000 Free Software Foundation, Inc.
;; Copyright (C) 2003, 2005, 2011, 2016, 2019 Tony Garnock-Jones <tonyg@leastfixedpoint.com>
;; This 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 2, or (at your option)
;; any later version.
;; This 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 software; see the file COPYING. If not, write to the
;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
;; Boston, MA 02111-1307, USA.
(require 'font-lock)
(require 'smie)
;;---------------------------------------------------------------------------
;; Font-lock, Indentation, and Mode
(defvar preserves-mode-syntax-table (make-syntax-table)
"Syntax table in use in preserves-mode buffers.")
;; (modify-syntax-entry ?' "\"" preserves-mode-syntax-table)
(modify-syntax-entry ?\n ">" preserves-mode-syntax-table)
(modify-syntax-entry ?\r ">" preserves-mode-syntax-table)
(modify-syntax-entry ?\; "<" preserves-mode-syntax-table)
(modify-syntax-entry ?< "(>" preserves-mode-syntax-table)
(modify-syntax-entry ?> ")<" preserves-mode-syntax-table)
(mapcar #'(lambda (x) (modify-syntax-entry x "_" preserves-mode-syntax-table))
'(?- ?_ ?$ ?? ?! ?* ?+ ?~ ?: ?= ?|))
(mapcar #'(lambda (x) (modify-syntax-entry x "." preserves-mode-syntax-table))
'(?.))
(defvar preserves-font-lock-keywords
(list
'("\\_<\\(~\\|[A-Z]\\)[^][)(}{><[:space:].\n]*\\>" . font-lock-type-face)
'("\\\\[[:space:]]*?\n" . font-lock-warning-face)
))
(defun preserves-mode-variables ()
(make-local-variable 'comment-use-syntax)
(make-local-variable 'comment-start)
(make-local-variable 'comment-end)
(make-local-variable 'comment-start-skip)
(setq comment-use-syntax t)
(setq comment-start ";")
(setq comment-end "")
(setq comment-start-skip "; *")
(make-local-variable 'font-lock-defaults)
(setq font-lock-defaults '(preserves-font-lock-keywords nil nil ()))
(make-local-variable 'indent-line-function)
(setq indent-line-function #'preserves-indent-line)
)
(defvar preserves-indent-basic 2
"Basic indentation amount for Preserves.")
(defun preserves-continuation-line-p ()
(save-excursion
(and (zerop (forward-line -1))
(progn (end-of-line)
(skip-syntax-backward " ")
(eq (char-before) ?\\)))))
(defun preserves-looking-at-syntax-p (ch)
(let ((ch-here (char-after)))
(and ch-here (eq (char-syntax ch-here) ch))))
(defun preserves-hanging-paren-p ()
(save-excursion
(forward-char)
(while (and (not (eq (char-after) ?\n))
(preserves-looking-at-syntax-p ?\s))
(forward-char))
(eolp)))
(defun preserves-indent-line ()
(let ((new-indentation
(save-excursion
(beginning-of-line)
(skip-syntax-forward " ")
(let* ((at-close-paren (preserves-looking-at-syntax-p ?\)))
(ppss (syntax-ppss)))
(cond
((cadddr ppss) nil) ;; when we are in a string, don't reindent
((<= (car ppss) 0) 0) ;; not in any parentheses, outdent fully
(t (goto-char (cadr ppss))
(cond
((preserves-hanging-paren-p)
(beginning-of-line)
(skip-syntax-forward " ")
(if at-close-paren ;; close paren, no indent
(current-column)
(+ preserves-indent-basic (current-column))))
(at-close-paren ;; close paren, treat it specially
(current-column))
(t ;; not a close paren, do the default thing
(forward-char)
(skip-syntax-forward " ")
(current-column)))))))))
(when new-indentation
(cl-labels ((reindent! () (indent-line-to (if (preserves-continuation-line-p)
(+ new-indentation preserves-indent-basic)
new-indentation))))
(if (bolp)
(reindent!)
(save-excursion (reindent!)))))))
;;;###autoload
(define-derived-mode preserves-mode prog-mode "Preserves"
"Major mode for editing Preserves structures."
(preserves-mode-variables))
;;---------------------------------------------------------------------------
;; Provides
(provide 'preserves-mode)
;;; preserves.el ends here