elm-pages-v3-beta/plugins/Shiki.elm
2022-02-06 16:24:40 -08:00

103 lines
3.2 KiB
Elm

module Shiki exposing (Highlighted, ShikiToken, decoder, view)
import Html exposing (Html)
import Html.Attributes as Attr exposing (class)
import Json.Decode as Decode exposing (Decoder)
import Json.Decode.Extra
type alias ShikiToken =
{ content : String
, color : Maybe String
, fontStyle : Maybe ( String, String )
}
type alias Highlighted =
{ lines : List (List ShikiToken)
, fg : String
, bg : String
}
decoder : Decoder Highlighted
decoder =
Decode.map3 Highlighted
(Decode.field "tokens" (Decode.list (Decode.list shikiTokenDecoder)))
(Decode.field "fg" Decode.string)
(Decode.field "bg" Decode.string)
shikiTokenDecoder : Decode.Decoder ShikiToken
shikiTokenDecoder =
Decode.map3 ShikiToken
(Decode.field "content" Decode.string)
(Json.Decode.Extra.optionalField "color" Decode.string)
(Json.Decode.Extra.optionalField "fontStyle" fontStyleDecoder |> Decode.map (Maybe.andThen identity))
fontStyleDecoder : Decoder (Maybe ( String, String ))
fontStyleDecoder =
Decode.int
|> Decode.map
(\styleNumber ->
case styleNumber of
1 ->
Just ( "font-style", "italic" )
2 ->
Just ( "font-style", "bold" )
4 ->
Just ( "font-style", "underline" )
_ ->
Nothing
)
{-| <https://github.com/shikijs/shiki/blob/2a31dc50f4fbdb9a63990ccd15e08cccc9c1566a/packages/shiki/src/renderer.ts#L16>
-}
view : List (Html.Attribute msg) -> Highlighted -> Html msg
view attrs highlighted =
highlighted.lines
|> List.indexedMap
(\lineIndex line ->
let
isLastLine =
List.length highlighted.lines == (lineIndex + 1)
in
Html.span [ class "line" ]
((line
|> List.map
(\token ->
Html.span
[ Attr.style "color" (token.color |> Maybe.withDefault highlighted.fg)
, token.fontStyle
|> Maybe.map
(\( key, value ) ->
Attr.style key value
)
|> Maybe.withDefault (Attr.title "")
]
[ Html.text token.content ]
)
)
++ [ if isLastLine then
Html.text ""
else
Html.text "\n"
]
)
)
|> Html.code []
|> List.singleton
|> Html.pre
([ Attr.style "background-color" highlighted.bg
, Attr.style "white-space" "pre-wrap"
, Attr.style "overflow-wrap" "break-word"
]
++ attrs
)