A Pandoc filter that identifies code blocks(Haskell), executes the code in GHCI and embeds the results in the returned Markdown.

Often a markdown(or any pandoc supported document) for any Haskell related documentation or a technical blog post involves code blocks. The code block could include definitions and also a demonstration of output with an interactive prompt. For, example, take this code block:

-- README.md -- definition increment:: Integer -> Integer increment x = x + 1 -- interactive prompt to demostrate the working of definitions so far >> increment 41

It would be nice if this code block was automatically evaluated and output of increment 41 is automatically recorded below >> increment 41, as follows:

-- README.md -- definition increment:: Integer -> Integer increment x = x + 1 -- interactive prompt to demostrate the working of definitions so far >> increment 41 42

Notice, that the 42 is automatically populated by this filter while transforming the original document.

To transform the document, we need to run the document through the pandoc filter, as follows:

-- set up pandoc_filter to the executable of this program (see Installation) pandoc -s -t json README.md | pandoc_filter | pandoc -f json -t markdown 

cd your_folder git clone https://github.com/gdevanla/pandoc-markdown-ghci-filter.git cd your_folder/pandoc-markdown-ghci-filter stack build # find build folder using the following command stack path --dist-dir # create a link to that executable depending on your OS # test it on a test_markdown file pandoc -s -t json README.md | pandoc_filter | pandoc -f json -t markdown