15. Loading

Loading a file of Lisp code means bringing its contents into the Lisp environment in the form of Lisp objects. Emacs finds and opens the file, reads the text, evaluates each form, and then closes the file.

The load functions evaluate all the expressions in a file just as the eval-current-buffer function evaluates all the expressions in a buffer. The difference is that the load functions read and evaluate the text in the file as found on disk, not the text in an Emacs buffer.

The loaded file must contain Lisp expressions, either as source code or as byte-compiled code. Each form in the file is called a top-level form. There is no special format for the forms in a loadable file; any form in a file may equally well be typed directly into a buffer and evaluated there. (Indeed, most code is tested this way.) Most often, the forms are function definitions and variable definitions.

A file containing Lisp code is often called a library. Thus, the "Rmail library" is a file containing code for Rmail mode. Similarly, a "Lisp library directory" is a directory of files containing Lisp code.

15.1 How Programs Do Loading		The load function and others.
15.2 Library Search		Finding a library to load.
15.3 Loading Non-ASCII Characters		Non-ASCII characters in Emacs Lisp files.
15.4 Autoload		Setting up a function to autoload.
15.5 Repeated Loading		Precautions about loading a file twice.
15.6 Features		Loading a library if it isn't already loaded.
15.7 Unloading		How to "unload" a library that was loaded.
15.8 Hooks for Loading		Providing code to be run when particular libraries are loaded.