The above discussion centers around input and output of characters with the high bit set. How jed treats them internally is another issue and new questions arise. For example, what is the uppercase equivalent of a character with ASCII code 231? This may vary from language to language. Some languages even have characters whose uppercase equivalent correspond to multiple characters. For jed, the following assumptions have been made:
define_case (X, Y);in the startup file. For example, suppose 211 is the uppercase of 244. Then, the line
define_case (211, 244);will make jed use this fact in operations involving the case of a character.
This has already been done for the ISO Latin 1 character set. See the file
iso-latin.sl
for details. For MSDOS, this will not work. Instead
use the files dos437.sl
and dos850.sl
. By default, jed's
internal lookup tables are initialized to the ISO Latin set for Unix and
VMS systems and to the DOS 437 code page for the IBMPC. To change the
defaults, it is only necessary to load the appropriate file. For example,
to load dos850.sl
definitions, put
evalfile ("dos850"); pop ();in the startup file (e.g.,
site.sl
). In addition to
uppercase/lowercase information, these files also contain word
definitions, i.e., which characters constitute a ``word''.