Proposal: Add hasBitSize to Data.Bits.Bits

Andreas Abel andreas.abel at
Sat Jul 28 18:57:37 CEST 2012

On 28.07.12 4:40 PM, John Lato wrote:
>> From: Edward Kmett <ekmett at>
>> On Fri, Jul 27, 2012 at 3:42 PM, Ian Lynagh <igloo at> wrote:
>>> On Fri, Jul 27, 2012 at 03:06:04PM -0400, Edward Kmett wrote:
>>>> There is currently no way to know whether or not calling
>>>> Data.Bits.bitSizewill crash your program.
>>>> I propose extending the Bits class to include:
>>>> hasBitSize :: Bits b => b -> Bool
> I'm in favor of changing the type of bitSize, although since none of
> my code uses that function it's an easy position for me to take.

+1.  The Haskellish solution would let return bitSize a Maybe.

Andreas Abel  <><      Du bist der geliebte Mensch.

Theoretical Computer Science, University of Munich
Oettingenstr. 67, D-80538 Munich, GERMANY

andreas.abel at

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