Hi,

I am not sure I understand the meaning of NO in the context of the previous 
message.

Is the NO related to the sumNumbers, or to the min, max?

Cheers,
Doru


> On Dec 20, 2015, at 2:43 PM, Sven Van Caekenberghe <[email protected]> wrote:
> 
> NO
> 
>> On 20 Dec 2015, at 14:32, Tudor Girba <[email protected]> wrote:
>> 
>> Hi,
>> 
>>> On Dec 20, 2015, at 2:30 PM, Max Leske <[email protected]> wrote:
>>> 
>>> 
>>>> On 20 Dec 2015, at 14:10, Tudor Girba <[email protected]> wrote:
>>>> 
>>>> Hi,
>>>> 
>>>> Could we not have sum, but sumNumbers instead? So, we would end up with:
>>>> 
>>>> sum:ifEmpty:
>>>> sum: (with error)
>>>> sumNumbers (without error)
>>>> 
>>>> From the outside, #sum: looks like it should parameterize #sum, but the 
>>>> implementation is actually different. So, given that in this 
>>>> implementation #sum is not a special case of #sum: the two should be named 
>>>> differently to reflect that difference. Hence my proposal is to keep 
>>>> #sumNumbers instead of #sum.
>>> 
>>> I could live with that. We would sacrifice the beautiful selector #sum for 
>>> the more intention revealing #sumNumbers. I think that makes sense.
>>> 
>>> Concerning the #min and #max methods that means we’d end up with e.g. 
>>> #minNumbers, #min: and #min:ifEmpty: etc.
>> 
>> Yes.
>> 
>> Doru
>> 
>> 
>>> 
>>>> 
>>>> Cheers,
>>>> Doru
>>>> 
>>>> 
>>>>> On Dec 20, 2015, at 1:47 PM, Max Leske <[email protected]> wrote:
>>>>> 
>>>>>> 
>>>>>> On 20 Dec 2015, at 13:43, Gabriel Cotelli <[email protected]> wrote:
>>>>>> 
>>>>>> Max,
>>>>>> 
>>>>>> sum: aBlock ifEmpty: emptyBlock needs to obtain the sample evaluating 
>>>>>> the block.
>>>>>> 
>>>>>> sum: aBlock ifEmpty: emptyBlock
>>>>>>  | sum sample |
>>>>>>  self isEmpty ifTrue: [ ^ emptyBlock value ].
>>>>>>  sample := aBlock value: self anyOne.
>>>>>>  sum := self
>>>>>>          inject: sample
>>>>>>          into: [ :accum :each | accum + (aBlock value: each) ].
>>>>>>  ^ sum - sample
>>>>> 
>>>>> 
>>>>> Thanks! Missed that.
>>>>> 
>>>>>> 
>>>>>> On Sun, Dec 20, 2015 at 8:59 AM, Max Leske <[email protected]> wrote:
>>>>>> I would like to wrap up this discussion. 
>>>>>> 
>>>>>> 
>>>>>>> On 05 Dec 2015, at 18:14, stepharo <[email protected]> wrote:
>>>>>>> 
>>>>>>> So what is the conclusion?
>>>>>>> I like the idea of Esteban M to have iterator because it moves some 
>>>>>>> behavior out of core classes.
>>>>>>> 
>>>>>>> [[[
>>>>>>> 
>>>>>>> aCollection arithmetic sum: [...] or.... aCollection
>>>>>>> arithmetic avg.
>>>>>>> 
>>>>>>> ]]]
>>>>>>> 
>>>>>> 
>>>>>> While I think that iterators are an intriguing idea I also believe that 
>>>>>> they are beyond the scope of this issue. If anybody wants to follow up 
>>>>>> on iterators (or unit types for that matter) please start a new thread / 
>>>>>> issue.
>>>>>> 
>>>>>> 
>>>>>> I propose to use Sven’s version for #sum:ifEmpty:. The result would be 
>>>>>> these three methods:
>>>>>> 
>>>>>> sum
>>>>>>  ^ self
>>>>>>          sum: [ :each | each ]
>>>>>>          ifEmpty: [ 0 ]
>>>>>> 
>>>>>> sum: aBlock
>>>>>>  ^ self
>>>>>>          sum: aBlock
>>>>>>          ifEmpty: [ self errorEmptyCollection ]
>>>>>> 
>>>>>> sum: aBlock ifEmpty: emptyBlock
>>>>>>  | sum sample |
>>>>>>  self isEmpty ifTrue: [ ^ emptyBlock value ].
>>>>>>  sample := self anyOne.
>>>>>>  sum := self
>>>>>>          inject: sample
>>>>>>          into: [ :accum :each | accum + (aBlock value: each) ].
>>>>>>  ^ sum - sample
>>>>>> 
>>>>>> 
>>>>>> I’ve attached a couple of benchmark results below. To me they show that
>>>>>> 1. the new implementation is maybe a tiny bit slower but insignificantly 
>>>>>> so (if you’re going for performance you’ll probably write your own 
>>>>>> optimised version anyway)
>>>>>> 2. there is no need to duplicate the code (like #sum and #sum: currently 
>>>>>> do). It’s perfectly fine to delegate to #sum:ifEmpty:
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>> In addition to the above changes I would like to remove #detectSum: (-> 
>>>>>> #sum:) and #sumNumbers (-> #sum).
>>>>>> 
>>>>>> 
>>>>>> Note that once we agree on changing this API, we will need to also 
>>>>>> change #detectMin:, #detectMax:, #min, #max as well as all overrides 
>>>>>> (e.g. RunArray, Interval) of these and of #sum et. al. to stay 
>>>>>> consistent. The changes would of course be in line with this change, 
>>>>>> such that every operation has a unary selector with a sensible default, 
>>>>>> one that takes a block and throws an error for empty collections and a 
>>>>>> third that takes a block for the iteration and one for the empty case.
>>>>>> 
>>>>>> 
>>>>>> Please cast your vote for these changes:
>>>>>> 
>>>>>> 1. Do you agree to changing #sum and #sum: in the suggested way?
>>>>>> 
>>>>>> 2. Do you agree to the removal of #detectSum:?
>>>>>> 
>>>>>> 3. Do you agree to the removal of #sumNumbers?
>>>>>> 
>>>>>> 4. Do you agree that the #max and #min selectors also need to be adapted?
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>> Thanks for you help.
>>>>>> 
>>>>>> Cheers,
>>>>>> Max
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>> Benchmarks
>>>>>> ============
>>>>>> (Note that these aren’t very good benchmarks. There’s quite some 
>>>>>> variation on each run.)
>>>>>> 
>>>>>> 
>>>>>> Machine:
>>>>>>  MacBook Pro (15-inch, Early 2011)
>>>>>>  CPU: 2.2 GHz Intel Core i7
>>>>>>  Memory: 8 GB 1333 MHz DDR3
>>>>>>  Disk: APPLE SSD TS512C (500 GB)
>>>>>> 
>>>>>> 
>>>>>> Benchmarks of the current versions:
>>>>>> 
>>>>>> [ (1 to: 1000000) asArray sum ] benchFor: 10 seconds.
>>>>>>  75 iterations, 7.470 per second
>>>>>> 
>>>>>> [ (1 to: 1000000) asArray sum: [ :e | e ] ] benchFor: 10 seconds.
>>>>>>  72 iterations, 7.128 per second
>>>>>> 
>>>>>> 
>>>>>> [ (1 to: 100) asArray sum ] benchFor: 10 seconds.
>>>>>>  1,189,477 iterations, 118,912 per second
>>>>>> 
>>>>>> 
>>>>>> [ (1 to: 100) asArray sum: [ :e | e ] ] benchFor: 10 seconds.
>>>>>>  1,171,467 iterations, 117,112 per second
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>> Benchmarks of the new versions:
>>>>>> 
>>>>>> [ (1 to: 1000000) asArray sum ] benchFor: 10 seconds.
>>>>>>  73 iterations, 7.244 per second
>>>>>> 
>>>>>> [ (1 to: 1000000) asArray sum: [ :e | e ] ] benchFor: 10 seconds.
>>>>>>  75 iterations, 7.480 per second
>>>>>> 
>>>>>> [ (1 to: 1000000) asArray sum: [ :e | e ] ifEmpty: [ 0 ] ] benchFor: 10 
>>>>>> seconds.
>>>>>>  72 iterations, 7.141 per second
>>>>>> 
>>>>>> 
>>>>>> [ (1 to: 100) asArray sum ] benchFor: 10 seconds.
>>>>>>  1,115,827 iterations, 111,560 per second
>>>>>> 
>>>>>> [ (1 to: 100) asArray sum: [ :e | e ] ] benchFor: 10 seconds.
>>>>>>  1,154,595 iterations, 115,425 per second
>>>>>> 
>>>>>> [ (1 to: 100) asArray sum: [ :e | e ] ifEmpty: [ 0 ] ] benchFor: 10 
>>>>>> seconds.
>>>>>>  1,102,358 iterations, 110,203 per second
>>>> 
>>>> --
>>>> www.tudorgirba.com
>>>> www.feenk.com
>>>> 
>>>> "There are no old things, there are only old ways of looking at them."
>>>> 
>>>> 
>>>> 
>>>> 
>>>> 
>>> 
>>> 
>> 
>> --
>> www.tudorgirba.com
>> www.feenk.com
>> 
>> "If you can't say why something is relevant, 
>> it probably isn't."
> 
> 

--
www.tudorgirba.com
www.feenk.com

"Beauty is where we see it."





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