====== Servisné pomôcky pre zobrazenie ======
Funkcie pre priebežné zobrazenie rôznych hodnôt

===== Reťazce =====
Formátované hodnoty

==== test_showData ====
Funkcia prevedie vstupný reťazec ''data'' na stĺpce, kde v každom riadku je vyjadrenie znaku reťazca v rôznych sústavách a kódoch. \\
Začiatok popisu obsahuje reťazec ''header''
<code kotlin>
fun test_showData(data: String, header: String) {
    val chars = data.toCharArray()
    var i = 0
    println("$header (columns: array, decimal, hexadecimal)")
    for (c in chars) {
        val charName = when(c.code) {
            0 -> "<NULL>"
            1 -> "<SOH>"
            2 -> "<STX> (Start of Text)"
            3 -> "<ETX> (End of transmission text)"
            4 -> "<EOT>"
            5 -> "<ENQ> (Enquiry)"
            6 -> "<ACK> (Acknowledgement)"
            7 -> "<BEL>"
            8 -> "<BS>"
            9 -> "<TAB>"
            10 -> "<LF>"
            11 -> "<VT>"
            12 -> "<FF>"
            13 -> "<CR>"
            14 -> "<SO>"
            15 -> "<SI>"
            16 -> "<DLE>"
            17 -> "<DC1>"
            18 -> "<DC2>"
            19 -> "<DC3>"
            20 -> "<DC4>"
            21 -> "<NAK> (Negative acknowledgement)"
            22 -> "<SYN>"
            23 -> "<ETB>"
            24 -> "<CAN>"
            25 -> "<EM>"
            26 -> "<SUB>"
            27 -> "<ESC>"
            28 -> "<FS> (Field Separator)"
            29 -> "<GS>"
            30 -> "<ES>"
            31 -> "<US>"
            32 -> "<space>"
            else -> ""
        }
        println(String.format("  : %4d  %3d  %2h  %c $charName", i++, c.code, c.code, c))
    }
    println("\n")
}

// examples:
test_showData(messageToSend, "Sent:")  // request
test_showData(buffer.toString(Charsets.UTF_8).substring(0, bytesRead), "Read:")  // data from socket

</code>