Nannying (was: Array comprehension syntax)

[Brendan Eich]

Allen Wirfs-Brock wrote:
> I agree that this is a real hazard. I think eliminating it requires 
> two token look-ahead.  If that is ok, then we could specify
>
> /ConciseBody /*:*
>
> [lookahead  ∉ { *{*}]/AssignmentExpression
> /*{*[lookahead ∉ { /IdentifierName/}] [lookahead ∉ { *:*}] 
> /FunctionBody /*}*
>

See 
http://wiki.ecmascript.org/doku.php?id=strawman:arrow_function_syntax&rev=1307152413 
and later revisions at

http://wiki.ecmascript.org/doku.php?do=revisions&id=strawman%3Aarrow_function_syntax

These lookahead(2) restrictions I drafted in the strawman stage of arrow 
function syntax are not enough if we keep extending object literals. But 
perhaps we should stop extending object literals.

/be