Context Coloring

Highlights code by scope. Top-level scopes are one color, second-level scopes are another color, and so on. Variables retain the color of the scope in which they are defined. A variable defined in an outer scope referenced by an inner scope is colored the same as the outer scope.

By default, comments and strings are still highlighted syntactically.

Features

• Light and dark customizable color schemes.
• JavaScript support:
  • Script, function and block scopes (and even catch block scopes).
  • Node.js "file-level" scope detection.
• Emacs Lisp support:
  • defun, lambda, let, let*, cond, condition-case, defadvice, dolist, quote, backquote and backquote splicing.
  • Works in eval-expression too.

Installation

Requires Emacs 24.3+. JavaScript language support requires js2-mode (or, if you use Tern, you may be interested in tern-context-coloring).

To install, run the command M-x package-install RET context-coloring RET, and then add the following to your init file:

;; JavaScript:
(add-to-list 'auto-mode-alist '("\\.js\\'" . js2-mode))
(add-hook 'js2-mode-hook #'context-coloring-mode)

;; Emacs Lisp:
(add-hook 'emacs-lisp-mode-hook #'context-coloring-mode)

;; eval-expression:
(add-hook 'eval-expression-minibuffer-setup-hook #'context-coloring-mode) ; 24.4+
(add-hook 'minibuffer-setup-hook #'context-coloring-mode)                 ; 24.3

Color Schemes

The Zenburn theme, featured in the screenshot above, now supports context coloring.

You can define your own colors by customizing faces like context-coloring-level-N-face, where N is a number starting from 0.

See here for some color schemes for popular custom themes.

Options

• context-coloring-syntactic-comments (default: t): If non-nil, also color comments using font-lock.
• context-coloring-syntactic-strings (default: t): If non-nil, also color strings using font-lock.
• context-coloring-javascript-block-scopes (default: nil): If non-nil, also color block scopes in the scope hierarchy in JavaScript.
• context-coloring-javascript-detect-top-level-scope (default: t): If non-nil, detect when to use file-level scope.