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two-way-stream

two-way-stream System Class

Class Precedence List:

two-way-stream, stream, t

Description:

A bidirectional composite stream that receives its input from an associated input stream and sends its output to an associated output stream.

See Also:

make-two-way-stream, two-way-stream-input-stream, two-way-stream-output-stream 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.

Expanded Reference: two-way-stream​

Overview​

A two-way-stream is a bidirectional composite stream that receives input from an associated input stream and sends output to an associated output stream.

Type Check​

(let ((two (make-two-way-stream
             (make-string-input-stream "x")
             (make-string-output-stream))))
  (typep two 'two-way-stream))
=> T

Bidirectional Nature​

(let ((two (make-two-way-stream
             (make-string-input-stream "x")
             (make-string-output-stream))))
  (list (input-stream-p two)
        (output-stream-p two)))
=> (T T)

Class Hierarchy​

(subtypep 'two-way-stream 'stream)
=> T
=> T