
Idiomatically determine all the lowercase and uppercase letters   (of the Latin [English] alphabet)   being used currently by a computer programming language.
The method should find the letters regardless of the hardware architecture that is being used (ASCII, EBCDIC, or other).



Task requirements
Display the set of all:

   lowercase letters 
   uppercase letters

that can be used (allowed) by the computer program,


where   letter   is a member of the Latin (English) alphabet:     a ──► z     and     A ──► Z.



You may want to mention what hardware architecture is being used, and if applicable, the operating system.



See also
 Idiomatically determine all the characters that can be used for symbols.


enum chartypes
   LOWER = -1, UPPER = 1, NOTLETTER = 0
end enum
 
function letter_case( ch as string ) as byte
    'exploits the fact that ucase and lcase consider non-letters to be
    'both upper and lower case
    if ucase(ch)=lcase(ch) then return NOTLETTER
    if ch = ucase(ch) then return UPPER
    return LOWER
end function
 
dim as uinteger i
for i = 0 to 255
    if letter_case(chr(i)) = LOWER then print chr(i);
next i
print
for i = 0 to 255
    if letter_case(chr(i)) = UPPER then print chr(i);
next i
print