[Haskell-cafe] "Graphical Haskell"

[peterv]

In the book "Haskell School of Expression", streams are nicely explained
using a graphical flow graph.

This is also done more or less in
http://research.microsoft.com/~simonpj/papers/marktoberdorf/Marktoberdorf.pp
t to explain monads and other concepts.

I would like to create a program that allows you to create such flow graphs,
and then let GHC generate the code and do type inference. 

I found a paper where Haskell is used to create a GUI application with
undo/redo etc for creating graphical Basian networks
(http://www.cs.uu.nl/dazzle/f08-schrage.pdf), so this gave me confidence
that I could it do all in Haskell.

Now, instead of generating Haskell code (which I could do first, would be
easier to debug), I would like to directly create an AST, and use an Haskell
API to communicate with GHC. 

I already found out that GHC indeed has such an API, but how possible is
this idea? Has this been done before? I only found a very old attempt at
this, confusingly also called "Visual Haskell", see
http://ptolemy.eecs.berkeley.edu/%7Ejohnr/papers/visual.html, but I can't
find any source code for that project.

I did a similar project in C# that generated C++ code, so I've done it
before, just not in Haskell.

Thanks a lot,
Peter