fast to compile version of https://gist.github.com/athanclark/0e29485cb245ff07a97730cfef365d10

fastCompareMonth.elm

module Main exposing (..)

import Date exposing (Month(..))


compareMonth : Month -> Month -> Order
compareMonth m1 m2 =
    case m1 of
        Jan ->
            case m2 of
                Jan ->
                    EQ

                _ ->
                    LT

        Feb ->
            case m2 of
                Jan ->
                    GT

                Feb ->
                    EQ

                _ ->
                    LT

        Mar ->
            case m2 of
                Jan ->
                    GT

                Feb ->
                    GT

                Mar ->
                    EQ

                _ ->
                    LT

        Apr ->
            case m2 of
                Jan ->
                    GT

                Feb ->
                    GT

                Mar ->
                    GT

                Apr ->
                    EQ

                _ ->
                    LT

        May ->
            case m2 of
                Jan ->
                    GT

                Feb ->
                    GT

                Mar ->
                    GT

                Apr ->
                    GT

                May ->
                    EQ

                _ ->
                    EQ

        Jun ->
            case m2 of
                Jan ->
                    GT

                Feb ->
                    GT

                Mar ->
                    GT

                Apr ->
                    GT

                May ->
                    GT

                Jun ->
                    EQ

                _ ->
                    EQ

        Jul ->
            case m2 of
                Dec ->
                    LT

                Nov ->
                    LT

                Oct ->
                    LT

                Sep ->
                    LT

                Aug ->
                    LT

                Jul ->
                    EQ

                _ ->
                    GT

        Aug ->
            case m2 of
                Dec ->
                    LT

                Nov ->
                    LT

                Oct ->
                    LT

                Sep ->
                    LT

                Aug ->
                    EQ

                _ ->
                    GT

        Sep ->
            case m2 of
                Dec ->
                    LT

                Nov ->
                    LT

                Oct ->
                    LT

                Sep ->
                    EQ

                _ ->
                    GT

        Oct ->
            case m2 of
                Dec ->
                    LT

                Nov ->
                    LT

                Oct ->
                    EQ

                _ ->
                    GT

        Nov ->
            case m2 of
                Dec ->
                    LT

                Nov ->
                    EQ

                _ ->
                    GT

        Dec ->
            case m2 of
                Dec ->
                    EQ

                _ ->
                    GT