[Haskell-cafe] ANN: A Functional Implementation of the Garsia-Wachs Algorithm

[Don Stewart]

nicolas.pouillard:
> Hi All,
> 
> Here is an Haskell implementation of an algorithm that builds a binary tree with
> minimum weighted path length from weighted leaf nodes given in symmetric order.
> 
> This can be used to build optimum search tables, to balance a
> 'ropes' data structure in an optimal way.
> 
> This module a direct translation from OCaml of a functional pearl
> by Jean-Christophe Filliâtre yesterday on ML Workshop 2008.
> 
> There was an interesting point to porting it to Haskell, indeed there is a
> crucial use of first-class references used only locally. A good reason to
> show the power of the ST monad and it's runST function!
> 
> Here is the hackage URL:
>   http://hackage.haskell.org/cgi-bin/hackage-scripts/package/garsia-wachs
> 
> And the darcs 2 URL:
>   http://darcs.feydakins.org/garsia-wachs
> 

And packaged for Arch,

    http://aur.archlinux.org/packages.php?ID=20149

-- Don