character escaper, used to escape or unescape semicolon, colon, comma, ctlf characters, etc.
how to use:
NSString *source = @";,\\;\\;\\;:\\:\\n";
XYCharacterEscaper* escaper = [XYCharacterEscaper escaperWithSource:source];
escaper.escapeSemicolon().escapeColon().escapeComma().escapeCTLF();
printf(escaper.value); // \;\,\;\;\;\:\:\n
escaper.unescapeSemicolon().unescapeColon().unescapeComma().unescapeCTLF();
printf(escaper.value); // ;,;;;::(\n)