[Haskell-cafe] Very crazy

Dougal Stanton ithika at gmail.com
Tue Sep 25 05:31:34 EDT 2007

On 25/09/2007, Andrew Coppin <andrewcoppin at btinternet.com> wrote:

> Type signature is
>   show_system :: [[Double]] -> String
> It takes a matrix representing a system of equations, and pretty prints
> it. Unfortunately, doing complex formatting like that is... well,
> complex. The input is quite simple (it's a bunch of numbers), the output
> is quite simple (it's a neatly formatted string), but the process in the
> middle is... a mess. I'd like to find a more readable way of doing stuff
> like this. It's not just this specific function; any general hints would
> be good. ;-)

In this instance I would suggest:

(1) Text.Printf
(2) Pull out some of those things into separate functions with
where/let clauses.

If it's a matrix you should probably have something like

> showMatrix = concatMap showRow

Since you'll be applying the same procedures to each line of digits.



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