Writes the required number of blank spaces to ensure that the next character will be written in a given column.
The generic function
stream-advance-to-column
writes enough blank spaces to
stream
to ensure that the next character is written at
column
. The generic function returns
t
if the operation is successful, or
nil
if it is not supported for this stream.
This function is intended for use by
print
and
format ~t
. The default method uses
stream-line-column
and repeated calls to
stream-write-char
with a
#\Space
character, and returns
nil
if
stream-line-column
returns
nil
.