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  ANSI Common Lisp   21 Streams   21.2 Dictionary of Streams

21.2.9 input-stream-p, output-stream-p Function

Syntax:
input-stream-p stream    generalized-boolean

output-stream-p stream    generalized-boolean

Arguments and Values:
stream - a stream.

generalized-boolean - a generalized boolean.

Description:
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.

Examples:
 (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.

Allegro CL Implementation Details:
None.

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