> On 20 Dec 2015, at 14:10, Tudor Girba <tu...@tudorgirba.com> 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. > > Cheers, > Doru > > >> On Dec 20, 2015, at 1:47 PM, Max Leske <maxle...@gmail.com> wrote: >> >>> >>> On 20 Dec 2015, at 13:43, Gabriel Cotelli <g.cote...@gmail.com> 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 <maxle...@gmail.com> wrote: >>> I would like to wrap up this discussion. >>> >>> >>>> On 05 Dec 2015, at 18:14, stepharo <steph...@free.fr> 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." > > > > >
