Re: [Haskell-cafe] ANN: has-0.4 Entity based records

Sorry for spamming, what I wanted to write is I think `has' has better interface than other record packages in types. There are many libraries to write function "takes an record has Foo and Bar and returns something." But writing type of the function is still difficult. I can't write such types using HList or records without reading documents. I think, using has, There's few effort to write such types. I think `has' fits the needs of Haskellers who have the good habit of writing a type of a function before its definition. On 14 May 2010 07:58, HASHIMOTO, Yusaku wrote:

On 11 May 2010 03:25, adam vogt wrote:

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On Tue, May 4, 2010 at 12:18 PM, HASHIMOTO, Yusaku wrote:

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This library is inspired by HList[2], and interfaces are stealed from data-accessors[3]. And lenses[4], fclabels[5], and records[6] devote themselves to similar purposes.

[2]: http://hackage.haskell.org/package/HList [3]: http://hackage.haskell.org/package/data-accessor [4]: http://hackage.haskell.org/package/lenses [5]: http://hackage.haskell.org/package/fclabels [6]: http://hackage.haskell.org/package/records

Enjoy!

-nwn

Which niche does `has' fit between extensible (and more complicated) records like HList and records vs the libraries that provide only accessors?

You may find `has' useful when you want to use a label name in more than one record structures. This is achieved by HList, records and wreckage, But I think has at its interface.