A generic function that determines if an object is an output stream.
output-stream-p stream => result
A generalized boolean.
The generic function
output-stream-p implements the standard function. There are methods with stream specialized on fundamental-stream, fundamental-input-stream and fundamental-output-stream that returns
t if stream is an output stream. If you want to implement a stream class with no inherent directionality (and thus does not inherit from fundamental-input-stream or fundamental-output-stream) but for which the directionality depends on the instance, then you should add specialized method for
There is an example in 24.2.3 Stream directionality.
LispWorks® User Guide and Reference Manual - 01 Dec 2021 19:30:30