add-typep-transformer

$Revision: 5.0.2.4 $

Function

Package: EXCL

Arguments: (type function)

This function is called for its side effects. The return value has no meaning. This function tells the compiler that a typep form:

(typep x 'type)

can be transformed into the form:

(funcall predicate x)

The compiler will make the transformation where possible.

type must be a type, typically defined by the user with deftype. predicate should be a function object or a symbol naming a function. That function must accept any Lisp object as a single argument and return nil if the object is not of type type, non-nil if it is of type type. remove-typep-transformer removes the transform.

See compiling.htm for general information on compiling and see 10.4 Adding typep-transformers in that document for more information on typep transforms.

The general documentation description is in introduction.htm. The index in index.htm.