Passing Curiosity


Literate Haskell


Last night I spent a while wrestling with latex, vim, make and ghc as part of my source-code reorganisation. One of the things I’ve been wanting for quite a while, is a vim syntax highlighting mode that understands the LaTeX literate Haskell syntax and displays both the Haskell code and the LaTeX code properly. Last night, I finally got it to work, though it has taken a bit of hackery in my Haskell files: I need to have a comment in every file so that the highlighter can detect the LaTeX.

This is a problem as the LaTeX detection heuristic appears to be:
  1. Look for a \documentclass macro (the begining of a LaTeX document); or
  2. Look for a LaTeX command; or
  3. Assume that the “literate” part is not LaTeX

Needless to say, this is rather annoying as I’m writing a program with a number of modules (and thus a number of files) and want to produce a single document from them. To ameliorate this problem, I just make sure to include a LaTeX-style comment on the first line of every literate Haskell file and use a few macros to do include imported modules into the LaTeX document.

I’m also using the listings package to pretty-print the Haskell code and my next goal is to use its custom keyword handling capabilities to automatically include the modules that we import (if they exist in our source tree and are LaTeX-style literate code).