ps.el

(defun postscript-process ()
  (get-buffer-process (get-buffer "*postscript*")))

(defun run-postscript ()
  (interactive)
  (require 'comint)
  (switch-to-buffer (make-comint "postscript" "gs")))
(push '("postscript" . utf-8) process-coding-system-alist)

(defun to-postfix (s)
  (if (atom s) `(,s)
    `(,@(cdr s)
      ,(car s))))

(defun send-postscript-no-newline (s &optional ps)
  (unless ps
    (setf ps (postscript-process)))
  (unless ps
    (error "no running postscript process"))
  (dolist (obj (to-postfix s))
    (if (listp obj)
	(send-postscript-no-newline obj ps)
      (comint-send-string ps (format "%s " obj)))))

(defun send-postscript (s &optional ps)
  (unless ps
    (setf ps (postscript-process)))
  (unless ps
    (error "no running postscript process"))
  (send-postscript-no-newline s ps)
  (comint-send-string ps "\n"))


(defun ps (&rest ss)
  (dolist (s ss) (send-postscript-no-newline s))
  (unless (postscript-process)
    (error "no running postscript process"))
  (comint-send-string (postscript-process) "\n"))

(defmacro with-ps-context (&rest body)
  `(ps ,@(mapcar (lambda (s) `(quote ,s)) body)))