Annotating an AST with type checking / source line number info

[Craig Innes]

Hi there,

I am not hugely familiar with compilers or the particulars of GHC, but am
interested in creating a few programs which manipulate Haskell source code
in particular ways. Two things I would like to be able to do are:

- Swap every occurrence of a particular type for a different / dummy value
of that type.

- Find the line / column number of every place a value of a particular type
is used