Re: Ascii as a subset

I sent this question off recently: Is there a definitive list of 
Character sets that have ASCII as  a subset?

I am looking for a way to determine if character set "foo" has US-ASCII 
as a subset.  Is there a definitive list?  Or some codification of this 
determination.  Some module or class I can call a method in:

var ascii_subset = Class::is_ascii_superset('some_charset');
if (ascii_subset) {
    ignore();
}
else {
    encode('utf-8','some_charset');
}

:: Dana C. Chandler III| Senior Software Engineer
:: e-Dialog | dchandler@e-dialog.com
:: 131 Hartwell Ave. | Lexington, MA 02421 
:: v: 781-372-3355 | f: 781-863-8118 
:: www.e-dialog.com



Dana C. Chandler III wrote:
> Is there a definitive list of Character sets that have ASCII as  a 
> subset?
>