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Returns #t
if the specified characters are have the appropriate
order relationship to one another; otherwise returns #f
. The
-ci
procedures don’t distinguish uppercase and lowercase letters.
Character ordering follows these portability rules:
(char<? #\0 #\9)
returns
#t
.
(char<? #\A
#\B)
returns #t
.
(char<? #\a
#\b)
returns #t
.
MIT/GNU Scheme uses a specific character ordering, in which characters
have the same order as their corresponding integers. See the
documentation for char->integer
for further details.
Note: Although character objects can represent all of Unicode, the model of alphabetic case used covers only ASCII letters, which means that case-insensitive comparisons and case conversions are incorrect for non-ASCII letters. This will eventually be fixed.