Elm-format: Removal of parens leads to invalid code.

[pdamoc]

module MinusErr exposing (..)


errFun : Int -> Int
errFun x =
    case x of
        (-1) ->
            0

        (-2) ->
            0

        _ ->
            1

compiles but after elm-format is converted to:

module MinusErr exposing (..)


errFun : Int -> Int
errFun x =
    case x of
        -1 ->
            0

        -2 ->
            0

        _ ->
            1

which does not compile.

[avh4]

Good catch!

[pdamoc]

I have accidentally reported this in elm-dev 0.18 topic as a parser error.

Shouldn't the formatted version be legal?

[avh4]

It seems to be illegal in 0.17.1 as well, so regardless of whether the compiler changes to allow it in the future, I think it's good for elm-format to work around it until then.

[avh4]

Is the version without parens legal in Elm 0.18?

[pdamoc]

It is still illegal in final 0.18 release.

[avh4]

This is also the case for Floats, as well as Ints. Interestingly, it is allowed by elm-compiler for the first case clause, but not for subsequent case clauses.

[avh4]

FYI, the relevant elm-compiler issue is https://github.com/elm-lang/elm-compiler/issues/1261

[avh4]

Fixed in 5ee5460...784de8f. This will be included in 0.5.2-alpha.