Re: Proposal: Make gcd total

On Tuesday 10 May 2011 08:02:50, Judah Jacobson wrote:

On Mon, May 9, 2011 at 3:49 PM, Daniel Fischer

wrote:

...

I would like to propose the elimination of the special error case

gcd 0 0 = error "Prelude.gcd: gcd 0 0 is undefined"

to replace it with

gcd 0 0 = 0

(which would be an automatic consequence of removing the above line).

In my email archives, I found two previous threads on the subject. Both ended up in favor of the proposal: http://www.haskell.org/pipermail/haskell/2001-December/008560.html http://www.haskell.org/pipermail/haskell-cafe/2009-May/060880.html

As a result of the latter discussion, a ticket was opened on GHC's trac: http://hackage.haskell.org/trac/ghc/ticket/3304 But it was eventually closed for lack of attention.

So if someone actually follows through with this as an official libraries submission (with a patch, deadline, etc.), the odds seem in favor of it.

I'll try to see it through, although the process seems rather daunting. It has annoyed me for too long. Patches for GHC are at http://hackage.haskell.org/trac/ghc/ticket/3304 (plural, because the error needs to be in the haskell98 and haskell2010 packages, since the report demands it). Although this time there has not been much discussion yet, I refer to the previous discussions linked by Judah, to conclude that after some discussion (albeit spread over many years), the proposal seems plausible. Following http://hackage.haskell.org/trac/haskell-prime/wiki/Process#Proposals I hereby volunteer to become the proposal owner. Cheers, Daniel