Add index as an optional parameter to #each block params

[tim-evans]

I would like to change the DOM styling of items according to their position.
The following image is an example of doing so in our app:

I would ideally like to write components that look at its index for rendering different display information:

{{#each emailAddresses as |emailAddress index|}}
  {{email-address-item email=emailAddress index=index}}
{{/each}}

[fivetanley]

this would be amazing. I wonder if you can have multiple block params. @mmun @mixonic @rwjblue

[stefanpenner]

@fivetanley you can (or will be able to). The index here would be lovely..

[mmun]

@tim-evans This should be easy to add if you're up for it. I think you can just change https://github.com/emberjs/ember.js/blob/master/packages/ember-views/lib/views/collection_view.js#L360 to [item, idx].

[tim-evans]

Ok! It seems strange that the test for this belongs in ember-htmlbars. It's a tad confusing