[Haskell-cafe] curious about sum

[Keith Sheppard]

OK, I think I went off on a tangent that isn't very useful anyway

thanks
-Keith

On Wed, Jun 17, 2009 at 6:32 PM, Lennart
Augustsson<lennart at augustsson.net> wrote:
> The creators of Haskell didn't pick any particular representation for numbers.
> (Well, literals are kind of In..tegers.)  You can pick what types you
> make instances of Num.
> Some of them are lazy, some of them are strict.
>
> On Wed, Jun 17, 2009 at 11:05 PM, Keith Sheppard<keithshep at gmail.com> wrote:
>> In lambda calculus numbers are just functions and you evaluate them
>> just like any other function. Haskell could have chosen the same
>> representation for numbers and all evaluation on numbers would be lazy
>> (assuming normal order evaluation). I think that would have been the
>> "Purist Lazy" way to go. That is not the way the creators of Haskell
>> designed language though... am i missing something?
>>
>> On Wed, Jun 17, 2009 at 4:05 PM, Lennart
>> Augustsson<lennart at augustsson.net> wrote:
>>> What do you mean by "literals are strict"?  Strictness is a semantic
>>> property of functions, and while literals can be overloaded to be
>>> functions I don't know what you mean.
>>>
>>> On Wed, Jun 17, 2009 at 9:50 PM, Keith Sheppard<keithshep at gmail.com> wrote:
>>>> Haskell's numeric literals are strict. You wouldn't want that to
>>>> change right? It seems to me that having sum and product be strict is
>>>> consistent with this.
>>>>
>>>> -Keith
>>>>
>>>> On Wed, Jun 17, 2009 at 11:15 AM, Thomas Davie<tom.davie at gmail.com> wrote:
>>>>>
>>>>> On 17 Jun 2009, at 13:32, Yitzchak Gale wrote:
>>>>>
>>>>>> Henk-Jan van Tuyl wrote:
>>>>>>>
>>>>>>> reverse
>>>>>>> maximum
>>>>>>> minimum
>>>>>>
>>>>>> Oh yes, please fix those also!
>>>>>
>>>>> import Prelude.Strict?
>>>>>
>>>>> Honestly, these functions are ones that I've *deffinately* used lazy
>>>>> versions of, in fact, in the cases of minimum/maximum I've even used ones
>>>>> that are super-lazy and parallel using unamb.
>>>>>
>>>>> It would be extremely odd to randomly decide "most people would want this to
>>>>> be strict" based on no knowledge of what they're actually doing.  Instead,
>>>>> why don't we stand by the fact that haskell is a lazy language, and that the
>>>>> functions we get by default are lazy, and then write a strict prelude as I
>>>>> suggest above to complement the lazy version.
>>>>>
>>>>> Bob
>>>>> _______________________________________________
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>>>>> Haskell-Cafe at haskell.org
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>>>>>
>>>>
>>>>
>>>>
>>>> --
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>>>
>>
>>
>>
>> --
>> keithsheppard.name
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>



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