String renderer (WIP)

.github/workflows/ci.yml

@@ -58,7 +58,7 @@ jobs:
       - name: elm-format
         run: npx --no-install elm-format --validate src/ benchmarks/src/ review/src/ examples/src/ tests/
       - name: Add elm-review, elm and elm-format to path
-        run: npm bin >> $GITHUB_PATH
+        run:  echo "${{ github.workspace }}/node_modules/.bin" >> $GITHUB_PATH
       - uses: sparksp/elm-review-action@v1
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

src/Markdown/Renderer.elm

@@ -1,14 +1,14 @@
 module Markdown.Renderer exposing
     ( Renderer, render
-    , defaultHtmlRenderer
+    , defaultHtmlRenderer, defaultStringRenderer
     , renderWithMeta
     )
 
 {-|
 
 @docs Renderer, render
 
-@docs defaultHtmlRenderer
+@docs defaultHtmlRenderer, defaultStringRenderer
 
 
 ## Attaching Metadata to Blocks
@@ -255,6 +255,163 @@ defaultHtmlRenderer =
     }
 
 
+{-| This renders the parsed markdown structs to a string.
+-}
+defaultStringRenderer : Renderer String
+defaultStringRenderer =
+    { heading =
+        \{ level, children } ->
+            (case level of
+                Block.H1 ->
+                    "# " ++ String.concat children
+
+                Block.H2 ->
+                    "## " ++ String.concat children
+
+                Block.H3 ->
+                    "### " ++ String.concat children
+
+                Block.H4 ->
+                    "#### " ++ String.concat children
+
+                Block.H5 ->
+                    "##### " ++ String.concat children
+
+                Block.H6 ->
+                    "###### "
+                        ++ String.concat children
+            )
+                ++ "\n\n"
+    , paragraph =
+        \strs ->
+            String.concat strs
+                ++ "\n\n"
+    , hardLineBreak = "  \n"
+    , blockQuote =
+        \strs ->
+            strs
+                |> List.map (\s -> "  " ++ s ++ "\n")
+                |> String.concat
+    , strong =
+        \s ->
+            String.concat
+                ("**" :: s ++ [ "**" ])
+    , emphasis =
+        \s ->
+            String.concat
+                ("*" :: s ++ [ "*" ])
+    , strikethrough =
+        \s ->
+            String.concat
+                ("~~" :: s ++ [ "~~" ])
+    , codeSpan =
+        \s ->
+            "`" ++ s ++ "`"
+    , link =
+        \link content ->
+            String.concat
+                [ "["
+                , String.concat content
+                , "]("
+                , link.destination
+                , ")"
+                ]
+    , image =
+        \imageInfo ->
+            String.concat
+                [ "!["
+                , imageInfo.alt
+                , "]("
+                , imageInfo.src
+                , ")"
+                ]
+    , text = identity
+    , unorderedList =
+        \items ->
+            items
+                |> List.map
+                    (\listitem ->
+                        case listitem of
+                            Block.ListItem Block.NoTask childs ->
+                                "- " ++ String.concat childs ++ "\n"
+
+                            Block.ListItem Block.IncompleteTask childs ->
+                                "- [ ]" ++ String.concat childs ++ "\n"
+
+                            Block.ListItem Block.CompletedTask childs ->
+                                "- [x]" ++ String.concat childs ++ "\n"
+                    )
+                |> String.concat
+    , orderedList =
+        \startingIndex items ->
+            items
+                |> List.indexedMap (\i item -> String.fromInt (i + startingIndex) ++ ") " ++ String.concat item ++ "\n")
+                |> String.concat
+    , html = Markdown.Html.oneOf []
+    , codeBlock =
+        \{ body, language } ->
+            String.concat
+                [ "```"
+                , language |> Maybe.withDefault ""
+                , "\n"
+                , body
+                , "```\n\n"
+                ]
+    , thematicBreak = "--------------------\n"
+    , table = String.concat >> (++) "\n"
+    , tableHeader =
+        -- we get the whole header as one string here, contained in a single element list.
+        List.map
+            twoheads
+            >> String.concat
+    , tableBody = List.foldr (\s l -> s :: "\n" :: l) [] >> String.concat
+    , tableRow = List.intersperse " | " >> String.concat
+    , tableHeaderCell =
+        \maybeAlignment strs ->
+            String.concat strs
+                ++ " | "
+                ++ (case maybeAlignment of
+                        Just Block.AlignLeft ->
+                            ":-"
+
+                        Just Block.AlignRight ->
+                            "-:"
+
+                        Just Block.AlignCenter ->
+                            ":-:"
+
+                        Nothing ->
+                            "--"
+                   )
+    , tableCell =
+        \_ strs ->
+            String.concat strs
+    }
+
+
+twoheads : String -> String
+twoheads headstr =
+    headstr
+        |> String.split " | "
+        |> toheads ( [], [] )
+        |> (\( heads, aligns ) ->
+                String.concat (List.intersperse " | " heads)
+                    ++ "\n"
+                    ++ String.concat (List.intersperse "|" aligns)
+                    ++ "\n"
+           )
+
+
+toheads : ( List String, List String ) -> List String -> ( List String, List String )
+toheads ( llst, rlst ) strs =
+    case strs of
+        l :: r :: cdr ->
+            toheads ( l :: llst, r :: rlst ) cdr
+
+        _ ->
+            ( List.reverse llst, List.reverse rlst )
+
+
 {-| Apply a `Renderer` to turn parsed `Markdown.Block`s into your rendered markdown view.
 -}
 render :