Add dee-mode.el for emacs

dee-mode.el

@@ -0,0 +1,59 @@
+;; A major mode for editing scripts written in Deelang
+
+(add-to-list 'auto-mode-alist '("\\.dee\\'" . dee-mode))
+
+(defface dee-function-param-face
+  '((t . (:slant italic
+	  :weight bold
+	  :foreground "orange")))
+  "A face to help identify function parameter in Deelang.")
+
+(defcustom dee-indent-offset 4
+  "Default indentation offset for Deelang."
+  :group 'dee
+  :type 'integer
+  :safe 'integerp)
+
+(defvar dee-mode-map
+  (let ((map (make-sparse-keymap)))
+    map)
+  "Keymap for Deelang files")
+
+(defvar dee-mode-syntax-table
+  (let ((table (make-syntax-table)))
+    (modify-syntax-entry ?# "<" table)
+    (modify-syntax-entry ?\n ">" table)
+    (modify-syntax-entry ?- "w" table)
+    (modify-syntax-entry ?? "w" table)
+    table)
+  "Syntax table for Deelang files")
+
+(defvar dee-font-lock-id-re
+  (rx (seq alpha (* (any alnum ?- ??)))))
+
+(defvar dee-font-lock-keywords
+  `(,(rx symbol-start
+	 (or
+	  "if" "elif" "else" "")
+	 symbol-end)
+    (,(rx (group (regexp dee-font-lock-id-re)) (* space) "<-")
+     (1 font-lock-variable-name-face))
+    (,(rx (group (regexp dee-font-lock-id-re)) (* space) "->")
+     (1 'dee-function-param-face))
+    (,(rx (group (regexp dee-font-lock-id-re)) (* space) "(")
+     (1 font-lock-function-name-face))))
+
+(defun dee-indent-line-function ()
+  'noindent) ;TODO
+
+(define-derived-mode dee-mode prog-mode "Dee"
+  "Major mode for editing scripts written in Deelang.
+
+\\{dee-mode-map}"
+  (set (make-local-variable 'indent-line-function)
+       #'dee-indent-line-function)
+  (set (make-local-variable 'font-lock-defaults)
+       `(,dee-font-lock-keywords
+	 nil nil nil nil)))
+
+(provide 'dee)