Proposal: Add &&& and *** to Data.Tuple

Josef Svenningsson josef.svenningsson at
Thu Sep 27 09:44:16 EDT 2007

Sorry for my slow reply.

On 9/21/07, Henning Thielemann <lemming at> wrote:
> On Fri, 21 Sep 2007, Josef Svenningsson wrote:
> > Henrik and Ian,
> >
> > You've expressed worries that having functions with the same name but
> > different types could be problematic since it would cause confusing
> > error messages. While I can sympathize with that argument I don't
> > think it is an argument against having such functions. It is an
> > indication that the tools we're using don't report errors very well.
> People often forget that there are more Haskell tools than the one
> compiler they use. There are also tools like Haddock, extended static
> checkers and tools that still do not exist, like an IDE for refactoring,
> which will be complicated by such extensions. Thus language extensions
> should be considered carefully before adoption. In this case, I have the
> feeling that people have just aversions against using the possibilities of
> the module system that already exist.
I'm not sure what you're talking about here. You refer to language
extensions but that was not what we were talking about. We were
talking about the potential problem of adding functions to a base
library module which have the same name as some other functions in the
base library. Ian and Henrik were worried that that might cause
confusing error messages to which I responded that I think that's a
problem with the tool that we shouldn't let that constrain the way we
design our libraries.

I hope that clear things up. And I totally agree with you that we
should use the name space handling features of the module system much
more that what we currently do. After all, that it what it is for!



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