input-stream-p, output-stream-p (original) (raw)

ANSI Common Lisp 21 Streams 21.2 Dictionary of Streams

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.