Elm-format: Elm-format should distinguish between different types of comments.

[amilner42]

At the moment, if you have no imports, you cannot comment the top most function of your file. That comment will be pulled to the top of the file.

Example:

module Bla exposing (..)

-- I want to add a comment here
type alias Bla =
    { }

but elm format will make this

module Bla exposing (..)

-- I want to add a comment here


type alias Bla =
    { }

If it's a doc-comment, {-| -}, it makes sense to pull it to the top because it only makes sense to have doc comments above functions if you have a doc-comment in the module as well. But it doesn't make sense to be pulling -- and {- -} to the top of the file. We should be able to comment the top most function of our files even if we have no imports.

[amilner42]

To elaborate, there seems to be a few more issues with the top comment. For example if I do have imports, then my first comment can be a doc-comment, but it can only be a doc-comment.

module Bla exposing (..)

import X


{-| Allowed
-}
type alias Bla =
    { }

But both of these will be reformatted:

module Bla exposing (..)

import X


-- This comment will be pushed up upon formatting
type alias Bla =
    { }

module Bla exposing (..)

import X


{- This comment will be pushed up upon formatting -}
type alias Bla =
    { }

[avh4]

This is a case where elm-format is making the behavior of elm-make/elm-compiler more clear: If a module has no imports, you cannot have a doc comment on the first definition unless you also have a doc comment for the module before it--this is due to the behavior of elm-make and how it parses documentation. elm-format adjusts the spacing to make it more obvious how elm-make will interpret your doc comments.