16 Definition Commands

The @deffn command and the other definition commands enable you to describe functions, variables, macros, commands, user options, special forms and other such artifacts in a uniform format.

In the Info file, a definition causes the entity category—`Function', `Variable', or whatever—to appear at the beginning of the first line of the definition, followed by the entity's name and arguments. In the printed manual, the command causes TeX to print the entity's name and its arguments on the left margin and print the category next to the right margin. In both output formats, the body of the definition is indented. Also, the name of the entity is entered into the appropriate index: @deffn enters the name into the index of functions, @defvr enters it into the index of variables, and so on (see Predefined Indices).

A manual need not and should not contain more than one definition for a given name. An appendix containing a summary should use @table rather than the definition commands.

• Def Cmd Template: Writing descriptions using definition commands.
• Def Cmd Continuation Lines: Continuing the heading over source lines.
• Optional Arguments: Handling optional and repeated arguments.
• deffnx: Group two or more `first' lines.
• Def Cmds in Detail: Reference for all the definition commands.
• Def Cmd Conventions: Conventions for writing definitions.
• Sample Function Definition: An example.