Re: Underscores in numbers for legibility Peter Bex 12 Apr 2019 20:08 UTC
On Fri, Apr 12, 2019 at 11:00:54PM +0300, Lassi Kortela wrote:
> > Same here for CHICKEN, but I'm a bit hesitant to go in and complicate
> > the numerical syntax of Scheme.  We just got rid of the ridiculous hash
> > syntax (which _really_ complicated Scheme numerical syntax)!
>
> I'm sympathetic to that - simplicity is good. I was thinking it would be
> best to only allow it between digits, and deny it at the beginning or end of
> a token. And perhaps also to disallow more than one consecutive underscore.
> So like this:
>
>   1_000_000    ; good
>   1_000_000_   ; bad
>   _1_000_000   ; bad
>   _10000000    ; bad
>   10000000_    ; bad
>   1__000_000   ; maybe bad
>
> If underscores are allowed at the beginning of a token, then there is more
> possibility of conflict -- e.g. in C you can write a function named '_123'.

I also think this will definitely break backwards compatibility for
non-base prefixed numbers.  That's actually worse than the complexity
(which is managable).

Cheers,
Peter