[Haskell-cafe] What Haskell Records Need

[Andrew Butterfield]

Ah yes - the joy of Haskell

It so easy to roll your own, rather than search to find someone else's
(better/more elegant) solution...   :-)


On 2 Aug 2012, at 11:41, Erik Hesselink wrote:

> On Thu, Aug 2, 2012 at 12:30 PM, Andrew Butterfield
> <Andrew.Butterfield at scss.tcd.ie> wrote:
>> 
>> On 2 Aug 2012, at 09:25, Erik Hesselink wrote:
>> 
>>> Isn't this exactly the problem solved by all the lens packages?
>>> Current popular ones are fclabels [0] and data-lens [1].
>>> 
>>> [0] http://hackage.haskell.org/package/fclabels
>>> [1] http://hackage.haskell.org/package/data-lens
>> 
>> Not sure what all of these do, but I have a simple solution I use
>> in my work:
> 
> They do exactly that. They create 'lenses' which are
> getters/setters/modifiers combined, and allow you to compose these to
> get/set/modify deep inside nested data types. Look at the examples in
> the fclabels documentation [2] for more details.
> 
> [2] http://hackage.haskell.org/packages/archive/fclabels/1.1.4/doc/html/Data-Label.html

--------------------------------------------------------------------
Andrew Butterfield     Tel: +353-1-896-2517     Fax: +353-1-677-2204
Lero at TCD, Head of Foundations & Methods Research Group
Director of Teaching and Learning - Undergraduate,
School of Computer Science and Statistics,
Room G.39, O'Reilly Institute, Trinity College, University of Dublin
                          http://www.scss.tcd.ie/Andrew.Butterfield/
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