Nannying (was: Array comprehension syntax)

Allen Wirfs-Brock allen at
Wed Sep 26 09:26:03 PDT 2012

On Sep 26, 2012, at 6:22 AM, Andreas Rossberg wrote:

> On 26 September 2012 15:02, Brendan Eich <brendan at> wrote:
>> Let's agree that AssignmentExpression is ok (required for the left-most
>> comprehension expression). The main nannying objection was to trying to ban
>> = at top level of if and for heads.
>> If we can settle on this, I'm ok with it given the custom grammar already
>> required for if and for in comprehensions. It's not like anyone will truly
>> want / need to write comma expressions in heads, as I said yesterday!
> Sounds good to me.

this is also what I favor, AssignmentExpression all around

>> Separate question to you: (for|let|if)+ is what Jason championed, are you on
>> board?
> Right, I see no reason to artificially restrict the syntax to specific
> cases, especially given that it wouldn't make the expansion any
> simpler. So I also favour (for|if)+ or (for|let|if)+ (having let makes
> sense, although it probably isn't super important).

To me, adding let in combination with multiple ifs feels like a significant extension to what was in the original proposal that was accepted for ES6.  It seems like the sort of proposal change that should be presented at a TC39 meeting.


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