7.2 Forms of dspecs

A dspec is one of:

• A symbol
• A setf function name
• A list starting with a symbol naming the class of definition ( method or defstruct for example).

A symbol which is used as a dspec always names a function or a macro.

(setf foo) is a name for a setf function.

Note: nil is not a legal dspec, because it cannot have a function definition. Therefore when a dspec API returns nil , this should be interpreted in the usual way as "not found" or "not applicable".

7.2.1 Canonical dspecs

LispWorks User Guide and Reference Manual - 21 Dec 2011