Page 351	Table of Contents	Index	Page 353
	Chapters
	1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 A, B, C, D, E

APPENDIX C. COMMON LISP STREAMS

Note that while a value of 0 from stream-line-column also indicates the beginning of a line,
there are cases where stream-start-line-p can be meaningfully implemented when stream- line-columncannot. For example, for a window using variable-width characters, the column
number isn't very meaningful, but the beginning of the line does have a clear meaning. The
default method for stream-start-line-p on class fundamental-character-output-streamuses stream-line-column, so if that is defined to return nil, then a method should be provided
for either stream-start-line-p or stream-fresh-line.

=> stream-write-string stream string &optional (start 0) end [Generic Function]
Writes the string string to stream. If start and end are supplied, they specify what part of
string to output. string is returned as the value. This is used by write-string. The default
method provided by fundamental-character-output-stream uses repeated calls to stream- write-char.

=> stream-terpri stream [Generic Function]
Writes an end of line character on stream, and returns false. This is used by terpri. The default
method does stream-write-char of #\Newline.

=> stream-fresh-line stream [Generic Function]
Writes an end of line character on stream only if the stream is not at the beginning of the line.
This is used by fresh-line. The default method uses stream-start-line-p and stream- terpri.

=> stream-finish-output stream [Generic Function]
Ensures that all the output sent to stream has reached its destination, and only then return false.
This is used by finish-output. The default method does nothing.

=> stream-force-output stream [Generic Function]
Like stream-finish-output, except that it may return false without waiting for the output to
complete. This is used by force-output. The default method does nothing.

=> stream-clear-output stream [Generic Function]
Aborts any outstanding output operation in progress, and returns false. This is used by clear- output. The default method does nothing.

=> stream-advance-to-column stream column [Generic Function]
Writes enough blank space on stream so that the next character will be written at the position
specified by column. Returns true if the operation is successful, or nil if it is not supported
for this stream. This is intended for use by pprint and format ~T. The default method uses
stream-line-column and repeated calls to stream-write-char with a #\Space character; it
returns nil if stream-line-column returns nil.

Page 351	Table of Contents	Index	Page 353
	Chapters
	1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 A, B, C, D, E