The Riammus has understand what i mean, I gave you examples but i have not more examples, anyway!
Everything I put in that example was correct? It was just basically random. Anyhow, if that was correct, then the examples using $len and isalnum will work fine except for unicode characters. Might not be a bad idea for isalpha and isalnum to match with unicode such as Japanese.
Anyhow, westor, if anything, your requirements would seem to make more sense for adding issymbol instead of ischar. Not only would it make more sense to people as far as what it's checking, but it would work well with the other is___ checks (you'd then have alpha,number,symbol to check and I think that would be all you'd need). Of course, what a symbol is would have to be determined for that and opinions on that may differ from person to person... probably why it's not there.