Unable to express specific heat capacity

[Mehgugs]

Encoding specific heat capacity isn't currently possible in elm-units. I'm primarily using this library for unitful calculations and conversions but am finding the lack of a Kelvin quantity problematic.

[ianmackenzie]

Hi @Mehgugs, have you looked at the Temperature module? It's perhaps slightly funky but it includes both a Temperature type (which is kind of its own specialized thing, since e.g. it doesn't make sense to add two temperatures, so it can't be a normal Quantity), but also a Temperature.Delta type which represents the difference between two temperatures and so is a normal Quantity. I think you should be able to use Temperature.celsiusDegrees for what you want; for instance, you can evaluate this in an Elm REPL:

> Energy.joules 10 |> Quantity.per (Temperature.celsiusDegrees 1.0 |> Quantity.per Mass.kilogram)
Quantity 10
    : Quantity.Quantity
          Float
          (
          Quantity.Rate
              Energy.Joules
              (Quantity.Rate Temperature.CelsiusDegrees Mass.Kilograms)
          )

(I will admit that the fact that Temperature.degreesCelsius gives you an absolute Temperature, and Temperature.celsiusDegrees gives you a Temperature.Delta, and Temperature.kelvins gives you an absolute Temperature is all a bit awkward - perhaps it would have been cleaner to split out a separate Temperature.Delta module so that Temperature.kelvins would give you a Temperature and Temperature.Delta.kelvins would give you a Temperature.Delta, but 🤷‍♂️)

[Mehgugs]

Thanks for the response (and for making this library)! I hadn't thought about using the Temperature.celsiusDegrees for both Celsius and Kelvin. I have some additional code for serializing units so I had a definition already referring to the kelvin functions and got a bit stuck in my head 😵

you can close this, but I would be interested in that re-organization of the modules if that happens in the future.