Re: [Haskell-cafe] NaN as Integer value

On Sun, Apr 14, 2013 at 7:53 PM, Kim-Ee Yeoh wrote:

On Sun, Apr 14, 2013 at 3:28 PM, wren ng thornton wrote:

...

Whereas the problematic values due to infinities are overspecified, so no matter which answer you pick it's guaranteed to be the wrong answer half the time.

Part of this whole problem comes from the fact that floats *do* decide to give a meaning to 1/0 (namely Infinity).

I'm not sure what you mean about overspecification here, but in setting 1/0 as +infinity (as opposed to -infinity), there's an easily overlooked assumption that the limit is obtained "from above" as opposed to "from below."

Not quite. 0.0 designates "positive zero" or +0.0 in IEEE 754 notation. There is also "negative zero" or -0.0 in IEEE 754 notation. If you want the limit from below, use negative zero. This is all standard IEEE 754 concepts. -- Gaby