make-two-way-stream input-stream output-stream → two-way-stream

input-stream — a stream.

output-stream — a stream.

two-way-stream — a two-way stream.

Returns a two-way stream that gets its input from input-stream and sends its output to output-stream.

(with-output-to-string (out) 
   (with-input-from-string (in "input...") 
     (let ((two (make-two-way-stream in out))) 
       (format two "output...") 
       (setq what-is-read (read two))))) → "output..." 
what-is-read → INPUT...

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