Hi!

I think that, in order to increase performance, you should stop the Any search when an element matches the condition. For example:

var list=[{id:1},{id:2},{id:3}];
Enumarable.From(list).Any(function(x){
return x.id==1;
});

This Any should not search in all items if the first item matches. Result will not vary if more than one element matches.

Currently Any is searching in all the items of the enumerable.

Anyway, awesome library, congratulations!

if (predicate(enumerator.Current())) return true;