`````

% pandoc -t native

  ```haskell

  let x = y

in y

   ```

^D

[CodeBlock ("",["haskell"],[]) "let x = y\nin y"]

`````

`````

% pandoc -t native

 ~~~ {.haskell}

  let x = y

 in y +

y +

 y

~~~

^D

[CodeBlock ("",["haskell"],[]) " let x = y\nin y +\ny +\ny"]

`````