> Why not? This would be very useful for constraining what can be
> put into a database, many (most?) of which do not support Unicode.
There are three, much better choices for specific problems like this:
1. Have the application throw an error if an out-of-range character
appears.
2. Convert the text to UTF-8 before storing it in the database (UTF-8
and ASCII are identical up to 0x7f)
3. Escape non-ASCII characters with character references before
storing the text in the database.
As I mentioned before, it's always better to be explicit about this
kind of thing -- syntactic subtlety is a bad thing.
All the best,
David
--
David Megginson david@megginson.com
http://www.megginson.com/