From: Jan Nieuwenhuizen <janneke@gnu.org>
Date: Sun, 11 Nov 2018 09:10:43 +0000 (+0100)
Subject: mes: Add char-downcase, char-upcase.
X-Git-Url: https://jxself.org/git/?p=mes.git;a=commitdiff_plain;h=9543962ece4671f0f53c85ef9728d1188e86f0a3

mes: Add char-downcase, char-upcase.

* mes/module/srfi/srfi-14.mes (char-downcase, char-upcase): New
function.
---

diff --git a/mes/module/srfi/srfi-14.mes b/mes/module/srfi/srfi-14.mes
index a0a96b92..2e925ec5 100644
--- a/mes/module/srfi/srfi-14.mes
+++ b/mes/module/srfi/srfi-14.mes
@@ -76,3 +76,15 @@
 
 (define (char-set-copy cs)
   (map identity cs))
+
+(define (char-upcase c)
+  (if (char-set-contains? char-set:lower-case c) (integer->char (- (char->integer c)
+                                                                   (- (char->integer #\a)
+                                                                      (char->integer #\A))))
+      c))
+
+(define (char-downcase c)
+  (if (char-set-contains? char-set:upper-case c) (integer->char (+ (char->integer c)
+                                                                   (- (char->integer #\a)
+                                                                      (char->integer #\A))))
+      c))