Streams which read or write Lisp character data from or to the outside
world – files, sockets or other external entities – require the
specification of a conversion between the external, binary data and the
Lisp characters. In ANSI Common Lisp, this is done by specifying the
:external-format
argument when the stream is created. The major
information required is an encoding, specified by a keyword
naming that encoding; however, it is also possible to specify
refinements to that encoding as additional options to the external
format designator.
In addition, SBCL supports various extensions of ANSI Common Lisp streams:
character
and
(unsigned-byte 8)
values.
format
).