Agreed. I think that's a pretty common way people think about null vs undefined, and it's consistent with the language's behavior.
Dave On Jul 10, 2011, at 3:09 PM, liorean wrote: > On 10 July 2011 22:23, David Herman <dher...@mozilla.com> wrote: >> Another common and useful fusion of two traversals that's in many Schemes is >> map-filter or filter-map: >> >> a.filterMap(f) ~~~ [res for [i,x] of items(a) let (res = f(x, i)) if (res >> !== void 0)] >> >> I rather arbitrarily chose to accept both null and undefined here as way to >> say "no element" -- a reasonable alternative would be to accept *only* >> undefined as "no element". > > The way I think of it is that in analogy to NaN being the Numbers that > represent no number, null is the Object that represents no object, in > other words a reasonable value to store to tell just that. The > undefined value is by analogy the value that represents no value, so > is the only value that should be a "no element". > > But that might be just my way of thinking about and distinguishing the > not-a-something special cases. > -- > David "liorean" Andersson > _______________________________________________ > es-discuss mailing list > es-discuss@mozilla.org > https://mail.mozilla.org/listinfo/es-discuss _______________________________________________ es-discuss mailing list es-discuss@mozilla.org https://mail.mozilla.org/listinfo/es-discuss
