Introduction, comprehensions beyond arrays

Brendan Eich brendan at
Sat May 11 18:04:19 PDT 2013

Mike Stay wrote:
> No change to the syntax, no change to the iterator semantics, and a
> compatible change to the flattening semantics (assuming the existence
> of Array.prototype.flatten).

The nested arrays cost, and no one wants 'em for the single [] 
comprehension case. If you want a tree of arrays, you can nest 
comprehensions. Therefore this will be an optimization burden for no 
gain in the common case.

What's wrong with functional style when you mean it? Comprehensions are 
about sugaring the common case.


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