Any plans to addsum helper?

[balinterdi]

I think having this could be useful:

(sum sectionTotal1 sectionTotal2)

[skeate]

Is there any appreciable difference between that and add?

[balinterdi]

@skeate No, there is none, I just did not see the add helper, sorry :)

[bj-mcduck]

@skeate, can you use the add helper for an array? {{add thisItem.arrayOfNumbers}}

A sum helper would be great for this, if add doesn't already do this.

[bj-mcduck]

I just tried this with ember-composable-helpers, the following didn't work:

{{add (map-by 'clientPriceCents' order.orderItems)}}

If there were some kind of splat method widely available the add method would be fine.
I think having a proper sum helper would be helpful though.

[bj-mcduck]

If I make a PR, would it be welcomed?

[skeate]

This would be trivial with a spread operator, which is in RFC: emberjs/rfcs#184

though that appears to be more focused on named arguments, and thus (if they don't see a use case for it) might not be implemented to support arrays.

I still don't agree with adding a separate sum helper, especially if it's not just an alias to add. Having to check the docs all the time to remember which was which would be a pain.

This should be doable with ember-composable-helpers, though. Perhaps {{reduce add (map-by 'clientPriceCents' order.orderItems}}? (can't test right now to see if that actually works)

One possibility for this addon would be to just do some typechecking. If we have one param and it's an array, return the sum of that. That does lead to "well why not flatten any arrays passed", and suddenly we're in space where behavior is not completely intuitive.

[bj-mcduck]

I was trying to test this out, but couldn't get it to work as you mentioned. Shelfing it for now though as I no longer need it for my use-case.
Thanks for the ideas! Hopefully it'll help people looking to do the same :)