Added ch>lower, ch>upper, >lower, >upper

diff --git a/library/collections/strings.factor b/library/collections/strings.factor
index 2f256f48f925dc612577d7dbb0ccb563f24a0c6a..10ab87eef5d3ecc52eb16044f2d389dcf985761e 100644 (file)
--- a/library/collections/strings.factor
+++ b/library/collections/strings.factor
@@ -20,6 +20,11 @@ PREDICATE: integer digit     CHAR: 0 CHAR: 9 between? ;
 PREDICATE: integer printable CHAR: \s CHAR: ~ between? ;
 PREDICATE: integer control   "\0\e\r\n\t\u0008\u007f" member? ;
 
+: ch>lower ( n -- n ) dup LETTER? [ HEX: 20 + ] when ;
+: ch>upper ( n -- n ) dup letter? [ HEX: 20 - ] when ;
+: >lower ( str -- str ) [ ch>lower ] map ;
+: >upper ( str -- str ) [ ch>upper ] map ;
+
 : quotable? ( ch -- ? )
     #! In a string literal, can this character be used without
     #! escaping?