FWIW, if I change fruits to a const list, the JS code looks like:

$.main = function() {
  for (var i = 0; i < 2; ++i)
    $.Primitives_printString($.toString$0($.List_apples_oranges[i]));
};

This comment was originally written by ngeoffray@google.com

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Actually, List.from returns a growable list by default. You need to pass the "growable:false" named parameter to get a fixed list.

In this case, it might be able to be specialized because the argument is a literal (growable list, but obviously not modified before being passeed).

Thanks Lasse, I misread this in the API docs:

"The returned list is growable if growable is true, otherwise it's a fixed length list."

I read that as "unless you set growable to true, it's fixed"

So I changed the code to:

NBodySystem bodies = new NBodySystem(new List.from([Body.Sun(),
                                      Body.Jupiter(),
                                      Body.Saturn(),
                                      Body.Uranus(),
                                      Body.Neptune()], growable: false));

but the generated JS is still:

    for (dx = null, dy = null, dz = null, distance = null, mag = null, i = 0; i < size; i = j) {
      if (i >= t1.length)
        throw $.ioore(i);

Added this to the Later milestone.

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This comment was originally written by ngeoffray@google.com

Added Triaged label.

This comment was originally written by ngeoffray@google.com

Set owner to @floitschG.

This comment was originally written by @bp74

I tried to optimize some of the JavaScript code generated by dart2js and found the same problem with the ".toList(growable: false)" method. The JavaScript code is smaller and runs faster if i create a "new List(size)" and copy all elements to the new list - which is a non growable list recognized by the compiler.

So it would be great if the compiler would optimize for List methods returning non growable lists.

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Removed this from the Later milestone.
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Friendly ping. Did we address this recently? https://code.google.com/p/dart/issues/detail?id=20012

cc @floitschG.

No. These issues are unrelated.

cc @herhut-ggl.

Removed Oldschool-Milestone-Later label.

Verified fix in 79a8654