[Haskell-cafe] Re: Matrices in Haskell

[Ivan Miljenovic]

On 21/03/07, apfelmus <apfelmus at quantentunnel.de> wrote:
> Concerning Sudoku, there is a beautiful talk from R. Bird
>
>    http://icfp06.cs.uchicago.edu/bird-talk.pdf

I based my Latin Squares algorithms on Bird's Functional Pearl article
"A Program to play Sudoku"

> > The other problem with using a list of lists is that the only reason I'm sure
> > that the matrix is valid (i.e. all the rows are the same length, etc.)
> > is because I created it that way, not because the data structure
> > requires it.
>
> You can use nested data types in order to ensure squareness, see also
>
>    C. Okasaki.
>    From Fast Exponentiation to Square Matrices: An Adventure in Types
>    http://www.eecs.usma.edu/webs/people/okasaki/pubs.html#icfp99

At first glance, this looks like the kind of thing I want.  Thanks!

-- 
Ivan Lazar Miljenovic