;;; A major mode for editing IRSIM netlists. Public domain. Created by
;;; Peter Scott <pjscott@iastate.edu> in 2008. To install, put
;;; irsim-mode.el somewhere that emacs will see it like you site-lisp/
;;; sirectory and stick something like this in your .emacs file:
;;;
;;; (autoload 'irsim-mode "irsim-mode" nil t)
;;; (setq auto-mode-alist
;;; (cons '("\\.sim$" . irsim-mode) auto-mode-alist))
;;;
;;; Note that this will override the default behavior for opening .sim
;;; files, which is to go into simula-mode. This might be a problem if
;;; you use both.
;;;
;;; Note also that this mode is opinionated. It has a very specific
;;; idea of how IRSIM code ought to be indented, and if you don't like
;;; it then just set irsim-use-fancy-indent to nil. I think that the
;;; default indentation method leads to very pretty files and easy
;;; typing, but YMMV.
(require 'font-lock)
(require 'cl)
;; Customizable variables:
;;;;;;;;;;;;;;;;;;;;;;;;;;
(defvar irsim-use-fancy-indent t
"Specifies whether irsim-mode should use fancy indentation or
plain. Default is fancy, but set it to nil for plan.")
(defvar irsim-tab-stops '(0 3 16 32 48 51)
"The starting column positions for each entry in a transistor
line using the fancy indent function. Change if you like.")
;; Some global variables
(defvar irsim-mode-version "0.1"
"The current version number of irsim-mode.")
(defvar irsim-mode-hook nil)
(defconst irsim-font-lock-keywords
(list
'("^[\t ]*[np]" . font-lock-builtin-face)
'("[a-zA-Z_][_-a-zA-Z0-9.]*" . font-lock-variable-name-face))
"Minimal highlighting expressions for IRSIM mode")
;; Define comment behavior and make underscores act as normal
;; characters for forward-word and backward-word behavior. This makes
;; a lot more sense than the default.
(defvar irsim-mode-syntax-table
(let ((irsim-mode-syntax-table (make-syntax-table)))
(modify-syntax-entry ?| "< " irsim-mode-syntax-table)
(modify-syntax-entry ?\n "> " irsim-mode-syntax-table)
(modify-syntax-entry ?\^m "> " irsim-mode-syntax-table)
(modify-syntax-entry ?_ "w" irsim-mode-syntax-table)
irsim-mode-syntax-table))
;; Indentation
;;;;;;;;;;;;;;
(defun irsim-line-type ()
"Returns the type of line in IRSIM code that the point is
on. Valid return values are 'transistor-line, 'comment-line, or
nil"
(save-excursion
(move-beginning-of-line nil)
(if (looking-at "^[\t ]*[np]")
'transistor-line
(if (looking-at "^[\t ]*\\|")
'comment-line))))
;; To indent a transistor line, just move the columns into place and
;; put the cursor at the last empty column. Or don't move it if there
;; are no more empty columns. Comment lines should not be indented.
(defun irsim-indent-line ()
"Indent the current line of IRSIM code properly"
(interactive)
(let ((at-end nil))
(if (looking-at "[\t ]*$")
(setq at-end t))
(if (eql (irsim-line-type) 'transistor-line)
(progn
(save-excursion
(save-restriction
;; Narrow to just this line
(narrow-to-region (line-beginning-position) (line-end-position))
(beginning-of-line)
(indent-line-to 0)
(let ((tab-stops (copy-seq irsim-tab-stops)))
(while (and tab-stops (not (looking-at "[\t ]*$")))
(while (looking-at "[\t ]")
(delete-char 1))
(indent-to-column (car tab-stops))
(setq tab-stops (cdr tab-stops))
(forward-word))
(when (and at-end tab-stops)
(message "yarr")
(end-of-line)
(indent-to-column (car tab-stops))))))
(if at-end (end-of-line)))
(if (eql (irsim-line-type) 'comment-line)
(save-excursion
(beginning-of-line)
(indent-line-to 0))))))
(defun irsim-mode ()
"Major mode for editing IRSIM netlists."
(interactive)
(kill-all-local-variables)
(make-local-variable 'font-lock-defaults)
(setq font-lock-defaults '(irsim-font-lock-keywords))
(set-syntax-table irsim-mode-syntax-table)
(set (make-local-variable 'comment-start) "| ")
(when irsim-use-fancy-indent
(set (make-local-variable 'indent-line-function) 'irsim-indent-line))
(setq mode-name "IRSIM"
major-mode 'irsim-mode)
(run-hooks 'irsim-mode-hook))
(provide 'irsim-mode)