char=?, char<?, char>?, char<=?, char>=? - character comparison
LIBRARY
(import (rnrs)) ;R6RS
(import (rnrs base)) ;R6RS
(import (scheme r5rs)) ;R7RS
(import (scheme base)) ;R7RS
SYNOPSIS
(char=? char char char ...)
(char<? char char char ...)
(char>? char char char ...)
(char<=? char char char ...)
(char>=? char char char ...)
DESCRIPTION
These procedures return #t if the results of passing their
arguments to char->integer are (respectively): equal, monotonically
increasing, monotonically decreasing, monotonically nondecreasing, or
monotonically nonincreasing, and #f otherwise.
In R6RS systems, these procedures impose a total ordering on the set
of characters according to their Unicode scalar values.
RETURN VALUES
Returns a single boolean value.
EXAMPLES
(char<? #\z #\ß) => #t
(char<? #\z #\Z) => #f
COMPATIBILITY
Both R6RS and R7RS define the order based on the Unicode scalar values
of characters, but R7RS not require full Unicode support and also
permits non-Unicode characters.
These procedures exist in R5RS and earlier reports, but they were only
required to support two arguments.
IEEE Scheme uses the ≤ and ≥ characters instead of <= and >= in the
procedure entries, but this is probably a typo.
ERRORS
This procedure can raise exceptions with the following condition types:
- &assertion (R6RS)
-
The wrong number of arguments was passed or an argument was outside its domain.
- R7RS
-
The assertions described above are errors.
Implementations may signal an error, extend the procedure's
domain of definition to include such arguments,
or fail catastrophically.
SEE ALSO
char-ci=?(3scm)
STANDARDS
R4RS,
IEEE Scheme,
R5RS,
R6RS,
R7RS
AUTHORS
This page is part of the
scheme-manpages
project.
It includes materials from the RnRS documents.
More information can be found at
https://github.com/schemedoc/manpages/.
Markup created by unroff 1.0sc, March 04, 2023.