Emacs: Evaluate Elisp Code

By Xah Lee. Date: . Last updated: .

To evaluate a single lisp expression, move your cursor to the right of the last closing parenthesis, and Alt+x eval-last-sexpCtrl+x Ctrl+e】.

To evaluate all elisp code in a text selection, Alt+x eval-region.

emacs lisp eval 2018-12-20 f4da8
eval emacs lisp code basics.

Here's ways to eval elisp code, roughly in order of usefulness:

Alt+x eval-last-sexpCtrl+x Ctrl+e
Eval lisp expression to the left of cursor.
Alt+x eval-region
Eval text selection.
Alt+x eval-buffer
Eval whole buffer.
Alt+x load-file
Eval a file. It prompts.
Alt+x eval-defun
Eval function definition block the cursor is in. (the elisp code must be well-indended, otherwise emacs may have problem finding function.) [see Emacs: narrow-to-defun, eval-defun, bug]
Alt+x eval-expression
Prompts you to type code.

Emacs Lisp Command Line Interface (REPL)

Alt+x ielm to start emacs interactive emacs lisp shell.

emacs elisp REPL ielm 2017 01 04
emacs lisp interactive command line interface (REPL) ielm

I recommend working in a buffer instead of REPL.

Working in a buffer (sometimes called notebook inteface) allows you to use full editing power, and eval any expression, in any order, anytime, anywhere. [see Interactive Shell/REPL vs Notebook Interface]

If you have a question, put $5 at patreon and message me on xah discord.
Or support me by Buy Xah Emacs Tutorial

Emacs Tutorial

Emacs Init

Emacs Keys

ELisp

ELisp Examples

ELisp Write Major Mode


ELisp

Basics

Basic Functions

Writing Command

Writing Script

Lisp Data Structure

Lisp Symbol

Elisp Misc