Re: Getting the variable number of a lexical local variable

[Bill Allombert <Bill.Allombert@math.u-bordeaux1.fr>]

On Tue, Feb 23, 2010 at 09:01:48AM -0500, Charles Greathouse wrote:
> > Actually, it is possible: just use the code 'n', not 'V='.
> 
> I mean that it's not (apparently) possible to get it from the existing
> signature.
> 
> > Well, you can use
> > sumformal(x,1, n, x^3 + 3)
> > instead. The only difference is the use of a comma instead of =.
> 
> I guess that's not too bad.  I don't suppose there's a way to overload
> it so that I can have it called with V=GGG or nGGG?

No, functionnal polymorphism is not available. The closer you can do is
to use DnGGG or GGGDn. This way the variable will be optionnal:

DnGGG:
sumformal(x, 1, n, x^3 + 3) or sumformal(, 1, n, x^3 + 3)
GGGDn:
sumformal(1, n, x^3 + 3, x) or sumformal(1, n, x^3 + 3)

Cheers,
Bill.