README

Adaptive version 0.22 2008-07-14
================================

This is a minor update to Adaptive version 0.21 to make it work with
recent versions of GHC and Hugs. Adaptive is now cabalized, and any
problems with the packaging is my fault, not Magnus.

Peter A. Jonsson, pj@csee.ltu.se


Adaptive version 0.21  2005-07-09
=================================

This is a Haskell (plus some extensions) implementation of a library
for incremental computing.  It closely follows the implementation in
the nice POPL 2002 paper "Adaptive Functional Programming", by Umut
Acar, Guy Blelloch and Bob Harper.  As of writing, their paper can be
found at

      http://ttic.uchicago.edu/~umut/papers/popl02.html

However, this Haskell library provides a monadic interface, which
doesn't need the "write" operation or the "destination" type.  In
addition, the monadic types enforce correct usage, which means that a
modifiable variable must be defined before it can be used.  This is
achieved within Haskell's type system plus some popular extensions
(multi-parameter classes and functional dependencies).

The library is parameterised over any monad that has references (such
as IO and ST).  This means that it should be possible to put it on top
of e.g. many GUI monads too.

There is a small demo program of a classical incremental computation
problem: a spreadsheet.  Try it by typing

   runhugs -98 spreadsheet.hs

and type, say 

  c0 <Return> Cell c1 <Return> c1 <Return> Const 42 <Return>.

This has been tested with the Hugs September 2006 version.

Feedback is welcome!

Magnus Carlsson, magnus@galois.com