Re: [Haskell-cafe] deepSeq vs rnf

On 24/11/06, Ross Paterson wrote:

On Fri, Nov 24, 2006 at 02:53:45PM +0000, Malcolm Wallace wrote:

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Ross Paterson wrote:

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Perhaps it would make sense to move all the NFData material to a new module called, say, Control.NormalForm, and maybe add a deepSeq function there. Control.Parallel.Strategies is a somewhat surprising place to find normal form functions, and most of the people who are using them aren't thinking about parallelism.

Agreed. [ Bikeshed time: Control.Evaluation.Strategies anyone? ]

The suggestion is a module containing just class NFData, instances for Prelude types, and perhaps

deepSeq :: NFData a => a -> b -> b deepSeq x y = rnf x `seq` y

Shouldn't it have something like NF in the name?

Well, it shouldn't just have that. There's more in Control.Parallel.Strategies which would be useful in general (e.g. seqList). Perhaps the hierarchy should flip into: Control.Strategies.Sequential Control.Strategies.Parallel Control.Strategies could reexport both. Another thing is that the library is presently under-documented as far as Haddock is concerned (what's the difference between >| and >||). It'd be nice if at least a short comment was added to each function.