* Fix line typed with wrong CAPS LOCK
* convert all UPPERCASE to LOWERCASE and vice versa
L=CURLINE.3()
N=''
LOW=1
UP=LENGTH(L)
IF BLOCK.1()='BOX' THEN DO
   LOW=BLOCK.3()
   UP=BLOCK.5()
END
DO I=LOW TO UP
   C=SUBSTR(L, I, 1)
   IF DATATYPE(C,'U') THEN C=LOWER(C)
   ELSE IF DATATYPE(C,'L') THEN C=UPPER(C)
   ELSE IF ISRUP(C) THEN C=RLOWER(C)
   ELSE IF ISRLOW(C) THEN C=RUPPER(C)
   N=N||C
END
'R' OVERLAY(N,L,LOW)
EXIT

ISRUP:PROCEDURE
/* Returns is letter is uppercase cyrillic */
PARSE ARG C
RETURN SIGN(POS(C,XRANGE('€','Ÿ')))

ISRLOW:PROCEDURE
/* Returns is letter is lowercase cyrillic */
PARSE ARG C
LOW=XRANGE(' ','¯') || XRANGE('à','ï')
RETURN SIGN(POS(C,LOW))

RLOWER:PROCEDURE
/* Translate string to lowercase cyrillic */
PARSE ARG C
LOW=XRANGE(' ','¯') || XRANGE('à','ï')
RETURN TRANSLATE(C,LOW,XRANGE('€','Ÿ'))

RUPPER:PROCEDURE
/* Translate string to lowercase cyrillic */
PARSE ARG C
LOW=XRANGE(' ','¯') || XRANGE('à','ï')
RETURN TRANSLATE(C,XRANGE('€','Ÿ'),LOW)