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input-stream-p, output-stream-p (Function)

— Function: input-stream-p stream generalized-boolean
— Function: output-stream-p stream generalized-boolean
Arguments and Values:

stream—a stream.

generalized-boolean—a generalized boolean.


input-stream-p returns true if stream is an input stream; otherwise, returns false.

output-stream-p returns true if stream is an output stream; otherwise, returns false.

 (input-stream-p *standard-input*)  true
 (input-stream-p *terminal-io*)  true
 (input-stream-p (make-string-output-stream))  false

 (output-stream-p *standard-output*)  true
 (output-stream-p *terminal-io*)  true
 (output-stream-p (make-string-input-stream "jr"))  false
Exceptional Situations:

Should signal an error of type type-error if stream is not a stream.