addons.md

Emacs Addons which are Useful for Teaching Common Lisp

This adds the following functionality to Emacs:

• Increase the font size of all buffers at once.
• Evaluate a Lisp expression and insert the result as a comment in the same file, as per the examples.

The first is useful when showing your editor to a large group. The second is useful when showing what each expression evaluates to.

Installation

To install them, a short Elisp script is supplied: eval-and-comment.el. Open this in Portacle and evaluate it with the Emacs command M-x eval-buffer.

Use

You can now zoom all buffers with C-M-= and zoom out with C-M--, and evaluate and comment an expression your cursor is in with C-c C-e.

Explanation

(package-refresh-contents)
(package-install 'lispy)
(package-install 'default-text-scale)
(package-install 'markdown-mode+)
(default-text-scale-mode)
(lispy-mode)
(global-set-key (kbd "C-c e") 'lispy-eval-and-comment)

Elisp

Elisp is a dialect of Lisp for writing commands to, and extending, the Emacs editor.

(package-refresh-contents)

Updates the list of available packages to install in Emacs. This is always a good idea before installing any new packages. Emacs packages are extensions to the Emacs editor.

(package-install 'lispy)

This installs the Emacs package lispy, which has a great many useful features and commands, but we're only going to use one of them.

(package-install 'default-text-scale)

This installs the Emacs package default-text-scale which takes care of the zooming in/out.

(default-text-scale-mode)

Turns on default-text-scale for all buffers. If you need to do this again you can type M-x default-text-scale.

(lispy-mode)

Turns on lispy mode for the current buffer. We do this to bring the function we want into scope.

(global-set-key (kbd "C-c C-e") 'lispy-eval-and-comment)

This globally binds the key sequence C-c C-e to the lispy function lispy-eval-and-comment.