domenic at domenicdenicola.com (2014-09-17T22:03:28.642Z)
On 9/10/14, 3:20 PM, Allen Wirfs-Brock wrote:
> why wouldn't a self-hoster just continue with:
>
> ```js
> for (let next of iter} {
> /* body */
> }
> ```
I feel like I'm missing something here.
"iter" is an iterator, not an iterable. So I don't think this will do
the right thing, unless I'm seriously missing something.
> Anything either ES or WebIDL does that is hostile to that pattern is counter productive as self-hosters are probably going to do that anyway, even if the semantics is a slight mismatch to the spec.
What I am trying to define in Web IDL is the semantics of methods that
take an argument which is either an iterable or something else. That
means they need to check whether the given thing is iterable, and if so
iterate, otherwise do something else. See the thread that ended up in
http://lists.w3.org/Archives/Public/public-script-coord/2013OctDec/0370.html
and the algorithm in that mail; that's what I'm specifying.
> whatever constitutes the loop "body"
OK. That's fairly straightforward.
> You also will need a finally clause, if the loop body contains any explicit returns.
It only does when the iterator claims there are no more things to be
had, in which case do I still want to be calling the return() thing?
On 9/10/14, 3:20 PM, Allen Wirfs-Brock wrote: > why wouldn't a self-hoster just continue with: > for (let next of iter} { > /* body */ > } I feel like I'm missing something here. "iter" is an iterator, not an iterable. So I don't think this will do the right thing, unless I'm seriously missing something. > Anything either ES or WebIDL does that is hostile to that pattern is counter productive as self-hosters are probably going to do that anyway, even if the semantics is a slight mismatch to the spec. What I am trying to define in Web IDL is the semantics of methods that take an argument which is either an iterable or something else. That means they need to check whether the given thing is iterable, and if so iterate, otherwise do something else. See the thread that ended up in http://lists.w3.org/Archives/Public/public-script-coord/2013OctDec/0370.html and the algorithm in that mail; that's what I'm specifying. >> Seems to me like it's just a matter of wrapping the relevant bits (which ones, though? > whatever constitutes the loop "body" OK. That's fairly straightforward. > You also will need a finally clause, if the loop body contains any explicit returns. It only does when the iterator claims there are no more things to be had, in which case do I still want to be calling the return() thing? -Boris