;;; nix-mode.el --- Major mode for editing Nix expressions ;; Author: Eelco Dolstra ;; URL: https://github.com/NixOS/nix/tree/master/misc/emacs ;; Version: 1.0 ;;; Commentary: ;;; Code: (defconst nix-font-lock-keywords '("\\<if\\>" "\\<then\\>" "\\<else\\>" "\\<assert\\>" "\\<with\\>" "\\<let\\>" "\\<in\\>" "\\<rec\\>" "\\<inherit\\>" "\\<or\\>" ("\\<true\\>" . font-lock-builtin-face) ("\\<false\\>" . font-lock-builtin-face) ("\\<null\\>" . font-lock-builtin-face) ("\\<import\\>" . font-lock-builtin-face) ("\\<derivation\\>" . font-lock-builtin-face) ("\\<baseNameOf\\>" . font-lock-builtin-face) ("\\<toString\\>" . font-lock-builtin-face) ("\\<isNull\\>" . font-lock-builtin-face) ("[a-zA-Z][a-zA-Z0-9\\+-\\.]*:[a-zA-Z0-9%/\\?:@&=\\+\\$,_\\.!~\\*'-]+" . font-lock-constant-face) ("\\<\\([a-zA-Z_][a-zA-Z0-9_'\-\.]*\\)[ \t]*=" (1 font-lock-variable-name-face nil nil)) ("<[a-zA-Z0-9._\\+-]+\\(/[a-zA-Z0-9._\\+-]+\\)*>" . font-lock-constant-face) ("[a-zA-Z0-9._\\+-]*\\(/[a-zA-Z0-9._\\+-]+\\)+" . font-lock-constant-face)) "Font lock keywords for nix.") (defvar nix-mode-syntax-table (let ((table (make-syntax-table))) (modify-syntax-entry ?/ ". 14" table) (modify-syntax-entry ?* ". 23" table) (modify-syntax-entry ?# "< b" table) (modify-syntax-entry ?\n "> b" table) table) "Syntax table for Nix mode.") (defun nix-indent-line () "Indent current line in a Nix expression." (interactive) (indent-relative-maybe)) ;;;###autoload (define-derived-mode nix-mode prog-mode "Nix" "Major mode for editing Nix expressions. The following commands may be useful: '\\[newline-and-indent]' Insert a newline and move the cursor to align with the previous non-empty line. '\\[fill-paragraph]' Refill a paragraph so that all lines are at most `fill-column' lines long. This should do the right thing for comments beginning with `#'. However, this command doesn't work properly yet if the comment is adjacent to code (i.e., no intervening empty lines). In that case, select the text to be refilled and use `\\[fill-region]' instead. The hook `nix-mode-hook' is run when Nix mode is started. \\{nix-mode-map} " (set-syntax-table nix-mode-syntax-table) ;; Font lock support. (setq font-lock-defaults '(nix-font-lock-keywords nil nil nil nil)) ;; Automatic indentation [C-j]. (set (make-local-variable 'indent-line-function) 'nix-indent-line) ;; Indenting of comments. (set (make-local-variable 'comment-start) "# ") (set (make-local-variable 'comment-end) "") (set (make-local-variable 'comment-start-skip) "\\(^\\|\\s-\\);?#+ *") ;; Filling of comments. (set (make-local-variable 'adaptive-fill-mode) t) (set (make-local-variable 'paragraph-start) "[ \t]*\\(#+[ \t]*\\)?$") (set (make-local-variable 'paragraph-separate) paragraph-start)) ;;;###autoload (progn (add-to-list 'auto-mode-alist '("\\.nix\\'" . nix-mode)) (add-to-list 'auto-mode-alist '("\\.nix.in\\'" . nix-mode))) (provide 'nix-mode) ;;; nix-mode.el ends here