# Known Issues
* For compatibility with original `doctest` parser
you cannot write
~~~~
{-# LANGUAGE MyPreferredExtension #-}
~~~~
Instead you must write
~~~~
:set -XMyPreferredExtension
~~~~
* In Literal Haskell files
only `\\begin{code} ... \\end{code}` blocks are scanned,
but not bird style code blocks.
* `prop>` does not support multi-line code,
because both original `doctest` and `haddock` do not support it.
* IO tests are not supported as `doctest` examples, so far.
We need a syntactic distinction for IO tests,
because `doctest-extract` does not employ a type-checker.
We could mark IO tests
with a specific `id` function, as in `ioTest $ runMyTest`
or a type annotation, as in `runMyTest :: IO ()`.