Incompatible dimensions with `-> <fn>` gives poor error message compared to `|> <fn>`

[triallax]

Compare:

>>> 2 |> celsius
error: while type checking
   ┌─ Module 'physics::temperature_conversion', File <builtin>/modules/physics/temperature_conversion.nbt:15:12
   │
15 │ fn celsius(t_kelvin: Temperature) -> Scalar = t_kelvin / kelvin - _offset_celsius
   │            ^^^^^^^^ Temperature
   │
   ┌─ <input:14>:1:1
   │
 1 │ 2 |> celsius
   │ ^    ------- incompatible dimensions in argument 1 of function call to 'celsius'
   │ │     
   │ Angle or Scalar or SolidAngle
   │
   = parameter type: Temperature
      argument type: Scalar         [= Angle, Scalar, SolidAngle]
     
     Suggested fix: multiply the function argument by a `Temperature` factor

>>> 2 -> celsius
error: while type checking
  ┌─ <input:16>:1:1
  │
1 │ 2 -> celsius
  │ ^ Scalar
  │
  = Incompatible types in function call: expected 'Temperature', got 'Scalar' instead

[rben01]

I think that this is actually appropriate. |> is for calling a function, -> is for unit conversion. The fact that these happen to be the same operation under the hood is something of a coincidence. I think intent-specific error messages make sense here.

[sharkdp]

I agree, but it might still be worth to see if this can be improved.