iterator as a unique name and the enumerate trap

Tom Van Cutsem at
Mon Oct 1 04:12:18 PDT 2012

2012/10/1 David Bruant <bruant.d at>

> What about making "enumerator" a unique name and remove the enumerate trap
> too?
> Proxies that want to redefine the behavior of for-in loop can just decide
> to return a different iterator than the target one.

Are you proposing that the unique symbol "enumerator" would then also allow
regular (non-proxy) objects to customize old for-in loops? If not, then it
makes little sense to change the interface from a trap to a unique name for

If yes, then we should ask ourselves the question: is this a useful hook
for regular objects to customize? I think it's not, really (bear in mind
that enumeration can only generate strings (property names), it's a good
deal less generic than iteration)

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