Hi All, I've implemented support for literate markdown in a branch [1]. After doing a search on the bug tracker to see if anyone had already worked on this I came across bug #4836 [2], which details some unexpected interactions between the markdown format, unlit and CPP. Specifically, unlit attempts to keep CPP in the comment sections of a literate file, which clashes with the way that headings are defined in markdown. The approach that I took is that when GHC is processing markdown files, it passes the -r and -# flags to unlit, causing it to remove CPP in the comment parts of the file. I've added support for .markdown and .md as source file extensions supported by GHC to be able to detect when this is necessary. CPP can still be used within code blocks, giving a path forward for the case where the file was generated by something that wishes to leave #line markers. I've documented the changes on the wiki at [3]. Does this approach sound reasonable? If so, should I attach a patch to #4836, or create a new ticket? Thanks! --trevor [1] https://github.com/elliottt/ghc/tree/literate-markdown [2] http://hackage.haskell.org/trac/ghc/ticket/4836 [3] http://hackage.haskell.org/trac/ghc/wiki/LiterateMarkdown