char-ci=?(3scm) Scheme Programmer's Manual char-ci=?(3scm)

char-ci=?, char-ci<?, char-ci>?, char-ci<=?, char-ci>=? - case-folded comparison 

(import (rnrs))                     ;R6RS
(import (rnrs unicode))             ;R6RS
(import (scheme r5rs))              ;R7RS
(import (scheme char))              ;R7RS


(char-ci=? char char char ...)
(char-ci<? char char char ...)
(char-ci>? char char char ...)
(char-ci<=? char char char ...)
(char-ci>=? char char char ...)

These procedures are similar to char=?, etc., but operate on the case-folded versions of the characters.

The -ci mnemonic stands for "case insensitive".

Returns a single boolean value. 

(char-ci<? #\z #\Z)  =>  #f
(char-ci=? #\z #\Z)  =>  #t
(char-ci=? #\ς #\σ)  =>  #t    ;not required by R7RS

These procedures are defined in terms of char-foldcase(3scm). Whatever compatibility concerns apply to that procedure also apply here, in addition to any concerns applicable to char<? etc.

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.

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.

char=?(3scm), char-foldcase(3scm)

R4RS, IEEE Scheme, R5RS, R6RS, R7RS

This page is part of the scheme-manpages project. It includes materials from the RnRS documents. More information can be found at https://weinholt.se/scheme/manpages/.

2021-02-20