




A generic function used by peek-char that returns a character on a given stream without removing it from the stream buffer.
The generic function stream-peek-char is used to implement peek-char, and corresponds to a peek-type of nil. The default method reads a character from the stream without removing it from the stream buffer, by using stream-read-char and stream-unread-char.
LispWorks User Guide and Reference Manual - 20 Sep 2017