Vassily Gavrilyak gavrilyak at
Mon Mar 19 12:28:13 PDT 2007

On 3/19/07, Brendan Eich <brendan at> wrote:
> On Mar 19, 2007, at 11:10 AM, Jeff Dyer wrote:
> >> Thank you for considering this. While I can imagine why this
> >> functionality was disabled in ES1-3 (to protect programmer from
> >> misprints), in typed language typer could be responsible for handling
> >> this, not grammar.
> >> Well, let's wait for Jeff to comment.
> >
> > I'm not sure the type system will help much since 'undefined' will
> > silently convert to a value of most types. An argument list with holes
> > looks like mistake to me. Why not force the user to say what he means?
> Agreed. The type checker is an optional strict mode, anyway, so it
> can't help catch mistakes even if hole is not compatible with
> undefined or other typed values.
> Note also that holes in arrays mean the property need not be
> allocated, which can save memory and survive hole-preserving
> operations. Not so with actual parameters or the arguments object, at
> least not in any implementation I know of. An arguments object is not
> an Array.
> >> Probably named parameters were already considered, in this case I'm
> >> sorry for disturbing, just failed to find it in spec.
> >
> > Named arguments has been discussed from time to time, but never had
> > the
> > support to become a serious proposal. Both proposals here are future
> > proof and so I say let's hold off for now. We need to have
> > something to
> > talk about when edition4 is done :)
> Agreed. Waldemar had these at one point, but we need to finish soon,
> so leaving things out is important -- especially when they can be
> done by object initialiser argument passing and destructuring formal
> parameters.
> /be

Thanks for all the clarifications. Resolving those two would make the
language just perfect for me, but that would be too much :-)
Good luck with deadline and my best wishes!

Vassily Gavrilyak

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