GNU Emacs Lisp Reference Manual

Chapter 11: Functions

A Lisp program is composed mainly of Lisp functions. This chapter explains what functions are, how they accept arguments, and how to define them.

• What Is a Function Lisp functions vs. primitives; terminology.
• Lambda Expressions How functions are expressed as Lisp objects.
• Function Names A symbol can serve as the name of a function.
• Defining Functions Lisp expressions for defining functions.
• Calling Functions How to use an existing function.
• Mapping Functions Applying a function to each element of a list, etc.
• Anonymous Functions Lambda expressions are functions with no names.
• Function Cells Accessing or setting the function definition of a symbol.
• Inline Functions Defining functions that the compiler will open code.
• Related Topics Cross-references to specific Lisp primitives that have a special bearing on how functions work.