Re: instance overlap in 6.6 candidate

2006-09-25 Thread Christian Maeder
Simon Peyton-Jones schrieb: > | instance Show [Equation] > | where > | showsPrec _ eqs = | in a `nicer' way than by the default list [...] > Perhaps. That's what I'd like feedback about. What do others think? Overlapping Show instances are desirable for debugging pu

Re: instance overlap in 6.6 candidate

2006-09-05 Thread Brian Smith
On 9/5/06, Simon Peyton-Jones <[EMAIL PROTECTED]> wrote: The old model was that every instance is potentially overlappable; andyou only need the flag when you *use* the instances.  But peoplecomplained that the clients of their library should not need to know"import Foogle and use -fallow-overlappi

Re: instance overlap in 6.6 candidate

2006-09-05 Thread Serge D. Mechveliani
On Mon, Sep 04, 2006 at 03:39:06PM +0100, Simon Peyton-Jones wrote: > | > | data Equation = ... > | instance Show Equation where ... > | > | instance Show [Equation] > | where > | showsPrec _ eqs = | in a `nicer' way than

RE: instance overlap in 6.6 candidate

2006-09-05 Thread Simon Peyton-Jones
| What are the disadvantages of compiling every library | with -fallow-overlapping-instances? It's not H98, so it has to be an option, enabled by a flag. Of course you are free to put the flag at the top of every module. Sergey's point is that the libraries are pre-compiled, so you can't add fla

Re: instance overlap in 6.6 candidate

2006-09-04 Thread Rene de Visser
"Simon Peyton-Jones" <[EMAIL PROTECTED]> schrieb im Newsbeitrag | | This gives the user possibility to redefine a certain part of the | library instance. | Is not ghc-6.4.1 better at this point? Perhaps. That's what I'd like feedback about. What do others think? ... Simon What are the disadva

Re: instance overlap in 6.6 candidate

2006-09-04 Thread Chris Kuklewicz
Simon Peyton-Jones wrote: | | data Equation = ... | instance Show Equation where ... | | instance Show [Equation] | where | showsPrec _ eqs = | | | This gives the user possibility to redefin

Re: instance overlap in 6.6 candidate

2006-09-04 Thread Ian Lynagh
On Mon, Sep 04, 2006 at 06:22:34PM +0400, Serge D. Mechveliani wrote: > > Here is an example of how I alayws was using overlaps with standard > instances. > > > data Equation = ... > instance Show Equation where ... > > instance Show [Equation]

RE: instance overlap in 6.6 candidate

2006-09-04 Thread Simon Peyton-Jones
| | data Equation = ... | instance Show Equation where ... | | instance Show [Equation] | where | showsPrec _ eqs = | | | This gives the user possibility to redefine a certain part of the | lib

instance overlap in 6.6 candidate

2006-09-04 Thread Serge D. Mechveliani
To my request on overlapping instances in 6.6 candidate Simon Peyton-Jones <[EMAIL PROTECTED]> writes on 4 Sep 2006 > [..] > > GHC 6.6's story is that an instance declaration can only be overlapped > if you compile that module with -fallow-overlapping-instances. Since > the list instance for S