1 Introduction

Most of the SXEmacs text editor is written in the programming language called SXEmacs Lisp. You can write new code in SXEmacs Lisp and install it as an extension to the editor. However, SXEmacs Lisp is more than a mere “extension language”; it is a full computer programming language in its own right. You can use it as you would any other programming language.

Because SXEmacs Lisp is designed for use in an editor, it has special features for scanning and parsing text as well as features for handling files, buffers, displays, subprocesses, and so on. SXEmacs Lisp is closely integrated with the editing facilities; thus, editing commands are functions that can also conveniently be called from Lisp programs, and parameters for customization are ordinary Lisp variables.

This manual describes SXEmacs Lisp, presuming considerable familiarity with the use of SXEmacs for editing. (See The SXEmacs Reference Manual, for this basic information.) Generally speaking, the earlier chapters describe features of SXEmacs Lisp that have counterparts in many programming languages, and later chapters describe features that are peculiar to SXEmacs Lisp or relate specifically to editing.

This is edition 3.4.