Re: Proposal: add new Data.Bits.Bits(bitZero) method (was: Proposal: Explicitly require "Data.Bits.bit (-1) == 0" property)

The last time this topic came up (back when Num was split off) the discussion was derailed by the idea of a Bool class and then forgotten. I've hoped for an explicit zero element since then. +1 zeroBits On Feb 16, 2014 8:45 AM, "Edward Kmett" wrote:

`bitZero` sounds like it should equal `bit 0`, which it doesn't.

zeroBits ?

-Edward

On Sun, Feb 16, 2014 at 11:42 AM, Herbert Valerio Riedel wrote:

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Hi,

On 2014-02-16 at 15:10:42 +0100, ARJANEN Loïc Jean David wrote:

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I'll have to come down against that proposal because, at least on amd64 for 64 bits-sized types (Int, Int64, Word & Word64), it doesn't works.

You're right, I don't know how I could have missed that :-/

Since the presumed pre-condition for the proposal (that 'bit (-1) == 0' would already hold) I hereby amend the proposal to

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Introduce a new class method

class Bits a where ... -- | Value with all bits cleared bitZero :: a ...

modulo naming of 'bitZero'

(I'm hesitant to consume "zero" from the namespace as was suggested by Henning) _______________________________________________ Libraries mailing list Libraries@haskell.org http://www.haskell.org/mailman/listinfo/libraries

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