[Formatter] Different infix operators might need to be printed differently

[chenglou]

I'm ok with this:

let a = 1 + 2 + 
  3 + 4;

As it is currently, but for stuff like pipe it's probably better like this:

let a =
  bla1 1
  |> bla2 2
  |> bla3 3

[jordwalke]

Does the first example actually happen?

[chenglou]

That's how it's currently formatted (string for example).
I'm ok with nothing but the second form. I can make that change if we switch to it.

[jordwalke]

We might actually just left align all infix operators by default (but that would be suboptimal for monadic infix operators which most people want to be written on the Right hand side).

[sztosz]

With pipe a long piece of code like this

let all_resources =
  ResourceMap.(
    empty
    |> add Resource1(module Resource1: Resource)
    |> add Resource1(module Resource2: Resource)
    |> add Resource3(module Resource3: Resource)
  )

get's converted by rfmt into this:

let all_resources =
  ResourceMap.(
    empty |> add Resource1 ((module Resource1): (module Resource)) |>
    add Resource1 ((module Resource2): (module Resource)) |>
    add Resource3 ((module Resource3): (module Resource))
  );

I think it's much more readable if the pipe stays at the beginning of the line it's piping to, rather than the end.

[hcarty]

There's a PR working on this: #1259

[chenglou]

This now converts exactly correctly.