No, absolutely not. By "lexical", I took Allen to mean the new reliably block-local binding forms: "let", "const", "class"
On Mon, Feb 17, 2014 at 2:17 PM, Erik Arvidsson <[email protected]>wrote: > I'm getting vary. Does that mean that you want to change the semantics > since ES5.1? > > > On Mon Feb 17 2014 at 5:12:24 PM, Mark S. Miller <[email protected]> > wrote: > >> +1. >> >> >> On Mon, Feb 17, 2014 at 2:06 PM, Allen Wirfs-Brock <[email protected] >> > wrote: >> >> See >> http://people.mozilla.org/~jorendorff/es6-draft.html#sec-delete-operator-runtime-semantics-evaluation >> >> >> A better statement of the question would be can we agree that lexical >> bindings created by eval are always non-deletable binding. Where or not is >> throws which the various modes is already determined by the existing spec. >> for delete based upon whether or not the binding is deletable. >> >> Allen >> >> >> >> >> On Feb 17, 2014, at 1:16 PM, Mark S. Miller wrote: >> >> In this context, there are two things you might mean by "throws": >> a) That this delete is an early error within the evaled program, and >> therefore throws before any of the code in the evaled program executes. >> b) That the delete is a dynamic error that happens when the delete >> executes, and therefore that the evaled code prior to the delete has >> executed before the error is thrown. >> >> -1 on #b. >> >> Assuming you mean #a, between #a and silence, I'm torn. Here are pros and >> cons: >> pro #a: The program is wrong. Silence fails to bring it to anyone's >> attention, making the mistake less likely to be fixed. And making it more >> likely the program's execution deviates from author's intent. >> con #a: Silence on sloppy wrong programs are least surprise, and is >> arguably the most vivid different between sloppy and strict. >> >> I doubt there's any sensible choices other than #a and silence. >> >> >> >> On Mon, Feb 17, 2014 at 12:52 PM, Allen Wirfs-Brock < >> [email protected]> wrote: >> >> So, #3 appears to be the winner. >> >> Given that, can we also agree that this is throws (or at least that the >> delete does nothing): >> >> eval ("let x=5; delete x;"); >> >> (bug https://bugs.ecmascript.org/show_bug.cgi?id=1111 ) >> >> Allen >> >> >> >> On Feb 17, 2014, at 8:02 AM, Erik Arvidsson wrote: >> >> I'm also fine with 3. >> >> On Mon Feb 17 2014 at 10:39:47 AM, Jeremy Martin <[email protected]> >> wrote: >> >> Happy to concede to #3 on my end. Just wanted to be clear that it seems >> to be optimizing for future happiness vs. least surprising behavior (which >> isn't a bad thing). >> >> >> On Mon, Feb 17, 2014 at 10:26 AM, Jorge Chamorro <[email protected] >> > wrote: >> >> On 17/02/2014, at 13:42, Andreas Rossberg wrote: >> > On 15 February 2014 06:10, Brendan Eich <[email protected]> wrote: >> >> Allen Wirfs-Brock wrote: >> >>> >> >>> Another consideration in the back of my mind is that there may be >> useful >> >>> to implementors to knowing that let/const/class declaration are never >> >>> dynamically added to a non-global environment. >> >> >> >> +lots, this should be front of mind. >> >> >> >> In a block, we want the bindings local to that block to be statically >> >> analyzable. We want no non-local mode effects. So, #3 still wins. >> > >> > Strongly seconded. >> >> And even thirded. >> >> -- >> ( Jorge )(); >> >> _______________________________________________ >> es-discuss mailing list >> [email protected] >> https://mail.mozilla.org/listinfo/es-discuss >> >> >> >> >> -- >> Jeremy Martin >> 661.312.3853 >> http://devsmash.com >> @jmar777 >> >> _______________________________________________ >> es-discuss mailing list >> [email protected] >> https://mail.mozilla.org/listinfo/es-discuss >> >> >> >> _______________________________________________ >> es-discuss mailing list >> [email protected] >> https://mail.mozilla.org/listinfo/es-discuss >> >> >> >> >> -- >> Cheers, >> --MarkM >> >> >> >> >> >> -- >> Cheers, >> --MarkM >> > > _______________________________________________ > es-discuss mailing list > [email protected] > https://mail.mozilla.org/listinfo/es-discuss > > -- Text by me above is hereby placed in the public domain Cheers, --MarkM
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