Precedence of yield in EcmaScript 6

Question

I have a function build that synchronously returns an object, that in turn contains a function run. This function returns a thunk and hence can be called using yield and a library such as co.

Basically the call looks like this:

yield build().run();

Now, the problem is that I want to make sure that the yield refers to run, not to build. How do I do that, without introducing a temporary variable as in the following snippet?

var temp = build();
yield temp.run();

Any ideas?

PS: I'm running this code on Node.js 0.11.x using the ´--harmony´ flag.

Answer 1

Little has higher precedence over the member operator and the call operator, so you're safe. Here's a reference for you MDN Operator Precedence. The yield is pretty far down there.

If you wanted to group yield to the build() call, you'd need an explicit grouping.

(yield build()).run()