Re: numeri

[David De La Harpe Golden]

Eli Zaretskii wrote:


> Actually, why not make the above return the number 4?  The Unicode
> Data File Format says that this property's value is ``an integer or
> rational number''.  We could even use 0.2 for characters such as
> "VULGAR FRACTION ONE FIFTH".  Isn't that better than `1/5'?

Bear in mind that 1/5 (0.2) isn't actually exactly representable by 
binary floating point, bit like the way 1/3 (0.333(3 recurring)) can't 
be written properly in decimal, so try in emacs lisp:

(format "%.20f" 0.2)

I'd tend to hold off on allowing the vulgar fractions to map to numbers 
without the programmer to do a conversion step and "own" the associated 
potential information loss - at least until there is no loss:  Emacs 
Lisp could one day get CL-like exact rational numbers I guess (though 
bignums would probably be a higher priority...)