function rlEncode str
    local charCount
    put 1 into charCount
    repeat with i = 1 to the length of str
        if char i of str = char (i + 1) of str then
            add 1 to charCount
        else
            put char i of str & charCount after rle
            put 1 into charCount
        end if
    end repeat
    return rle
end rlEncode

function rlDecode str
    repeat with i = 1 to the length of str
        if char i of str is not a number then
            put char i of str into curChar
            put 0 into curNum
        else
            repeat with n = i to len(str)
                if isnumber(char n of str) then
                    put char n of str after curNum
                else
                    put repeatString(curChar,curNum) after rldec
                    put n - 1 into i
                    exit repeat
                end if
            end repeat
        end if
        if i = len(str) then --dump last char
            put repeatString(curChar,curNum) after rldec
        end if
    end repeat
    return rldec
end rlDecode

function repeatString str,rep
    repeat rep times
        put str after repStr
    end repeat
    return repStr
end repeatString