Build system idea

[Simon Peyton-Jones]

| Yes this means that Cabal is less general than autoconf.  It was quite a
| revelation when we discovered this during the design of Cabal - originally
| we were going to have everything done programmatically in the Setup.hs
| file, but then we realised that having the package configuration available
| *as data* gave us a lot more scope for automation, albeit at the expense of
| some generality.

Now there's a useful insight for the paper I hope Duncan (or someone) is going to write

        configuration as code [autoconf]
vs
        configuration as data [cabal]

Simon