In addition to the basic output stream protocol, CLIM defines an extended output stream protocol. This protocol extends the stream model to maintain the state of a text cursor, margins, text styles, inter-line spacing, and so forth.
The extended output stream protocol is discussed in the following two sections, "The Text Cursor" and "Text."
extended-output-stream [Protocol Class]
Summary: The protocol class for CLIM extended output streams. This is a subclass of output-stream . If you want to create a new class that behaves like an extended output stream, it should be a subclass of extended-output-stream . Subclasses of extended-output-stream must obey the extended output stream protocol.
extended-output-stream-p [Function]
Summary: Returns t if object is a CLIM extended output stream; otherwise, it returns nil .
Summary: All subclasses of extended-output-stream must handle these initargs, which are used to specify, respectively, the medium foreground and background inks, default text style, vertical spacing, default text margin, end of line and end of page actions, and the default view for the stream.
standard-extended-output-stream
Summary: This class provides an implementation of the CLIM extended output stream protocol, based on the CLIM output kernel.
Members of this class are mutable.
Common Lisp Interface Manager 2.0 User's Guide - 3 Mar 2015