On Wed, Jun 12, 2013 at 07:47:22AM +, harry wrote:
> Tillmann Rendel writes:
>
> > In general, I would be against removing features just because they are
> > confusing for beginners. I don't think that's a good design principle
> > for a language that is primarily targeted at professional p
Tillmann Rendel writes:
> In general, I would be against removing features just because they are
> confusing for beginners. I don't think that's a good design principle
> for a language that is primarily targeted at professional programmers
> and computer scientists.
They're confusing to begi
Johan Tibell writes:
> If we truly believe that the instance is dangerous for users (and not
merely for people who don't understand floating point arithmetic on
computers), then we should add a deprecation pragma to the instance and
discourage its use. But what would the deprecation message encou
* Johan Tibell [2013-06-11 15:03:10-0700]
> On Tue, Jun 11, 2013 at 3:00 PM, Roman Cheplyaka wrote:
>
> > Does such thing as a deprecation pragma for an instance exist?
> > What triggers it?
> >
>
> I don't know. We'll need one if we're going to deprecating core instances.
> Just deleting them
On Tue, Jun 11, 2013 at 3:00 PM, Roman Cheplyaka wrote:
> Does such thing as a deprecation pragma for an instance exist?
> What triggers it?
>
I don't know. We'll need one if we're going to deprecating core instances.
Just deleting them is not an option (as it gives users with large code
bases n
Does such thing as a deprecation pragma for an instance exist?
What triggers it?
Roman
* Johan Tibell [2013-06-11 14:18:41-0700]
> If we truly believe that the instance is dangerous for users (and not
> merely for people who don't understand floating point arithmetic on
> computers), then we sho
Hi,
The primary motivation for removing these instances is that they cause
endless confusion for beginners [...]
Not sure what that means for this discussion, but enumFromTo is already
confusing without considering floating point numbers:
Prelude> [fromInteger 1, fromInteger 3 .. fromInteg
On Tue, Jun 11, 2013 at 2:18 PM, Johan Tibell wrote:
> If we truly believe that the instance is dangerous for users (and not merely
> for people who don't understand floating point arithmetic on computers),
> then we should add a deprecation pragma to the instance and discourage its
> use. But wha
If we truly believe that the instance is dangerous for users (and not
merely for people who don't understand floating point arithmetic on
computers), then we should add a deprecation pragma to the instance and
discourage its use. But what would the deprecation message encourage
instead, for users t
More to supply evidence in answer to your question than to present a point
of view, the following is an example of code I wrote fairly recently:
phi :: Double -> Double -> Complex Double
phi x y = sum [ exp((-pi * (x + n)^2) :+ (2 * pi * n * y)) | n <-
[-100..100] ]
I wouldn't claim for a second
Johan Tibell writes:
> I don't see much gain. It will break previously working code and the
workaround to the breakage will likely be manually reimplementing enumFromTo
in each instance.
I forgot the main point of my post :-)
The primary motivation for removing these instances is that they caus
> I don't see much gain. It will break previously working code and the
> workaround to the breakage will likely be manually reimplementing enumFromTo
> in each instance.
As an aside, many years ago I did exactly that after being bit by Enum
infelicities, and while you could say it's a reimplementa
Hi Harry,
On Tue, Jun 11, 2013 at 3:51 AM, harry wrote:
> There have been several discussions over the years regarding Enum instances
> for Float and Double. The conclusion each time appears to have been that
> there are no instances which are both sane and practical.
>
Do you have a link to so
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