Ecto: Support mathematical infix operators

Created on 21 Oct 2016 · 14Comments · Source: elixir-ecto/ecto

I was wondering if there was any interest with adding common mathematical infix operators (+, -, *, and /) to the Query API.

I am interested in knowing if this is desired and would be accepted as a contribution.

Enhancement Advanced

Source

isaacsanders

👍1

Most helpful comment

@costaraphael nobody is working on it afaik, please go ahead!

josevalim on 5 Aug 2017

👍2

All 14 comments

It is a desired addition. The main obstacle would be proper type handling. We have to properly handle at least integers, floats and decimals.

In fact we had infix operators at some point, but when the typechecking was improved, they were dropped until reimplemented.

michalmuskala on 21 Oct 2016

Yes, the best solution is to include an "abstract" type called :number and make sure Ecto's type system accepts :integer, :float and :decimal as numbers.

josevalim on 22 Oct 2016

Where would I find sufficient test cases?

Where would one need to add the typechecking?

isaacsanders on 24 Oct 2016

The type checking happens in Ecto.Query.Builder (compile time) and Ecto.Query.Planner (runtime). I am not sure what you mean by test cases. I believe they would need to be written by whoever is working on the feature.

josevalim on 24 Oct 2016

@josevalim @michalmuskala said that there used to be infix in the codebase. I thought there might be test cases that already existed (in the git history) for the lower level modules, like Ecto.Query.Builder and Ecto.Query.Planner.

isaacsanders on 24 Oct 2016

@isaacsanders I don't think they would be relevant at this point. They existed way before 1.0 and the builder and planner were quite different from today.

josevalim on 24 Oct 2016

makes sense.

isaacsanders on 24 Oct 2016

Hi, is anyone working on this issue? If not I would love to tackle it. (Or try my best at least :sweat_smile:)

costaraphael on 5 Aug 2017

👍1

@costaraphael nobody is working on it afaik, please go ahead!

josevalim on 5 Aug 2017

👍2

Awesome, I should take a look at this week!

costaraphael on 5 Aug 2017

@josevalim is there anything left to do here or it can be closed?

wojtekmach on 23 Feb 2018

We are missing documentation for the newly supported operators in Ecto.Query.API. @costaraphael could you please send a PR for that too? Thank you! :heart:

josevalim on 23 Feb 2018

Whoops, I forgot about that :sweat_smile:

The docs should go to Ecto.Query.API, right?

Also, should I document for the new type usage (type(p.views + ^arg + ^other_arg, :decimal)) on the type/2 docs?

costaraphael on 23 Feb 2018