Re: [Haskell-cafe] Little errors in number calculations

It's curious that Hugs "lies"... Thanks for the answers :) . 2009/11/15 Lennart Augustsson :

Hugs is wrong, as you can easily see by evaluating   let x = 123.35503 * 10.0 in x == read (show x) With ghc it comes out as True and with Hugs as False.

 -- Lennart

On Sat, Nov 14, 2009 at 9:00 PM, Abby Henríquez Tejera wrote:

...

Hi.

I've seen that in GHC sometimes there are little errors in some basic number calculations:

*Prelude> 123.35503 * 10.0 1233.5502999999999

*Prelude> properFraction 123.35503 (123,0.3550299999999993)

whereas in Hugs no such errors seem to occur (that I have found, at least):

*Hugs> 123.35503 * 10.0 1233.5503

(but:)

*Hugs> properFraction 123.35503 (123,0.355029999999999)

I understand that error may (and will) happen in floating point, but it surprises me that they do so easily, and, above all, the difference between GHC and Hugs. Does someone know why does this difference occur?

(Thanks in advance, by the way :) ). _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe