I assume unexpected input results in either an error (or exception, whatever your language calls it), a crash or a user complaint. I also assume it's unlikely f

I assume unexpected input results in either an error (or exception, whatever your language calls it), a crash or a user complaint. I also assume it's unlikely for an input parser to introduce a security issue into your app if it's written in a safe language and your app has proper validation set up (i.e. don't trust input as soon as it passes the parser).