More fun with undefined
brendan at mozilla.com
Fri Jun 15 04:41:09 PDT 2012
This isn't unrelated. If we do get patterns into Harmony they may
subsume some of the postfix-?? (which does not work syntactically, IMHO)
or prefix-? ideas. Or at least prefix-? may show up in the pattern
language (dherman and I have discussed it).
Syntax design requries global oversight, there are cross-cutting
concerns and different complexity budgets to bean-count (but never too
locally or blindly).
T.J. Crowder wrote:
> On 15 June 2012 08:09, Andreas Rossberg <rossberg at google.com
> <mailto:rossberg at google.com>> wrote:
> On 15 June 2012 01:22, Allen Wirfs-Brock <allen at wirfs-brock.com
> <mailto:allen at wirfs-brock.com>> wrote:
> > A wonder if this wart is hairy enough, that we wouldn't be
> justified in some
> > explicit backwards compatibility hackery in the spec. to remove it.
> > For example, we could allow it to appear in parameter lists and
> provide a
> > dynamic check to ensure that nothing (other than a real
> undefined) is
> > passed. Similarly we could explicitly allow:
> > var undefined;
> Actually, for very much the same effect, you could simply treat
> 'undefined' as a (refutable) _pattern_ that is only matched by the
> undefined value. No need to make special rules for var or parameters
> Folks, could we move the unrelated discussion to its own thread? This
> thread's original subject is rather getting lost here.
> -- T.J.
> es-discuss mailing list
> es-discuss at mozilla.org
More information about the es-discuss