Generic Function

Summary

A generic function that determines if an object is an output stream.

Package

common-lisp

Signature

output-stream-p stream => result

Arguments

stream

A stream.

Values

result

A generalized boolean.

Description

The predicate output-stream-p is implemented as a generic function. The default method returns t if stream is an output stream. If the user wants to implement a stream with no inherent directionality (and thus does not include fundamental-input-stream or fundamental-output-stream) but for which the directionality depends on the instance, then a method should be provided for output-stream-p.

Examples

There is an example in Stream directionality.

See also

fundamental-output-stream
input-stream-p