Ken Shan wrote:
> I think the rule you're looking for is the following: Don't equate a
> type variable with something that contains that type variable. This
> is known as the "occurs check". This rule prohibits "equi-recursive"
> types like "b" above, but not "iso-recursive" types like
>
> d
Jeffrey A. Scofield wrote:
> Say I have the following function, adapted from Pierce, Types and
> Programming languages:
>
> f n () = (n, f (n + 1))
But a simple modification seems to cures the problem:
> newtype W = W (Int, () -> W)
>
> f n () = W (n, f (n + 1))
>
> w2list (W (n,f)) = n:(w2l
G'day all.
Quoting Sven Panne <[EMAIL PROTECTED]>:
> Granted, C++'s (copy) constructors, destructors and assignment operators make
> some
> things relatively easy compared to C, but the complexity of handling
> exceptions
> *correctly* makes things worse again: There is a famous article (I can't
Jeremy Shaw wrote:
> There is a thread on comp.lang.functional that talks about why haskell
> does not support recursive types:
>
> http://groups.google.com/groups?q=ocaml+rectypes&hl=en&lr=lang_en&ie=UTF-8&oe=UTF-8&safe=off&selm=8giqpt%24oee%241%40rivesaltes.inria.fr&rnum=1
>
> (searching for '
Sven Panne <[EMAIL PROTECTED]> writes:
> [ Just one more mail and I promise to shut up on this topic... :-) ]
Surely slamming C++ is on topic? :-)
> Fergus Henderson wrote:
>> [...] C does suffer from many of the same problems as C. But in C++, it is
>> much easier to automate techniques like
On 2003-12-08T12:42:46-0800, Jeffrey A. Scofield wrote:
> b = () -> (a, b)
> [...]
> I'm wondering how to tell, as a relative newcomer to
> Haskell, that they aren't allowed.
I think the rule you're looking for is the following: Don't equate a
type variable with something that contains that ty
[EMAIL PROTECTED] wrote:
> > Say I have the following function, ... :
> >
> > f n () = (n, f (n + 1))
> > ...
> > I have two questions:
> >
> > 1. How can I tell from the Haskell 98 Revised Report that this
> > function isn't allowed? The discussions of typing in the Report
> > gener
[ Just one more mail and I promise to shut up on this topic... :-) ]
Fergus Henderson wrote:
[...] C does suffer from many of the same problems as C. But in C++, it is
much easier to automate techniques like reference counting, which can
be done manually in C but are much more cumbersome and erro
