> On 15.06.2017, at 22:52, Chris Muller <asqueaker at gmail.com> wrote:
> 
> ^ self select: [ : each | seen addNew: each ]

I would expect that to return each not true/false…
> 
> ?
> 
> 
> On Thu, Jun 15, 2017 at 3:50 PM, Chris Cunningham
> <cunningham.cb at gmail.com> wrote:
>> 
>> 
>> On Thu, Jun 15, 2017 at 1:22 PM, Tobias Pape <Das.Linux at gmx.de> wrote:
>>> 
>>> 
>>>> On 15.06.2017, at 21:40, Eliot Miranda <eliot.miranda at gmail.com> wrote:
>>>> 
>>>> Hi Tobias,
>>>> 
>>>> On Thu, Jun 15, 2017 at 12:32 PM, Tobias Pape <Das.Linux at gmx.de> wrote:
>>>> 
>>>>> On 15.06.2017, at 21:22, Chris Cunningham <cunningham.cb at gmail.com>
>>>>> wrote:
>>>>> 
>>>>> #testMissingThenAdd:  ?
>>>>> 
>>>> 
>>>> #isAdding:
>>>> #ingests:
>>>> 
>>>> #wasAbsentButNowIsPresent:
>>>> 
>>>> (just rambling…)
>>>> 
>>>> I like added:.  Its concise, accurate and reads nicely:
>>> 
>>> 
>>> Ok, but then maybe #addedNew: ? So as we know more than just an adding
>>> operation succeeded… :)
>> 
>> 
>> So it reads:
>> 
>> ^self select: [:each| seen addedNew: each]
>> 
>> I like that how that reads.
>> 
>> #added: wasn't bad - but I could see myself thinking it meant roughly 'was
>> this value already in the collection'?  Which misses the add part and is
>> backwards on the result (true if present, false if added).
>> 
>> -cbc
>>> 
>>> 
>>>> 
>>>> withoutDuplicates
>>>>      "Answer a copy of the receiver that preserves order but eliminates
>>>> any duplicates."
>>>>      | seen |
>>>>      seen := Set new: self size.
>>>>      ^self select: [:each| seen added: each]
>>>> 
>>>> messagesDo: aBlock
>>>>      "Evaluate aBlock exactly once with all the message selectors sent
>>>> by me."
>>>> 
>>>>      | scanner aSet |
>>>>      self isQuick ifTrue: [ ^self ].
>>>>      scanner := InstructionStream on: self.
>>>>      scanner scanFor: [ :x |
>>>>              | selector |
>>>>              (selector := scanner selectorToSendOrSelf) == scanner
>>>> ifFalse: [
>>>>                      ((aSet ifNil: [ aSet := IdentitySet new ]) added:
>>>> selector) ifTrue: [
>>>>                              aBlock value: selector ] ].
>>>>              false "keep scanning" ]
>>>> 
>>>> 
>>>> 
>>>>> On Jun 15, 2017 12:19 PM, "Eliot Miranda" <eliot.miranda at gmail.com>
>>>>> wrote:
>>>>> Hi Tobias,
>>>>> 
>>>>> On Thu, Jun 15, 2017 at 12:06 PM, Tobias Pape <Das.Linux at gmx.de>
>>>>> wrote:
>>>>> 
>>>>>> On 15.06.2017, at 20:30, Eliot Miranda <eliot.miranda at gmail.com>
>>>>>> wrote:
>>>>>> 
>>>>>> Hi Levente, Hi Chris,
>>>>>> 
>>>>>> On Wed, Jun 14, 2017 at 1:10 PM, Levente Uzonyi
>>>>>> <leves at caesar.elte.hu> wrote:
>>>>>> On Wed, 14 Jun 2017, commits at source.squeak.org wrote:
>>>>>> 
>>>>>> Eliot Miranda uploaded a new version of Collections to project The
>>>>>> Trunk:
>>>>>> http://source.squeak.org/trunk/Collections-eem.756.mcz
>>>>>> 
>>>>>> ==================== Summary ====================
>>>>>> 
>>>>>> Name: Collections-eem.756
>>>>>> Author: eem
>>>>>> Time: 14 June 2017, 11:03:24.917631 am
>>>>>> UUID: 8d7c03bc-1cdb-44c7-9173-10d50c0dae29
>>>>>> Ancestors: Collections-eem.755
>>>>>> 
>>>>>> Add SequenceableCollection>>withoutDuplicates for a more elegant fix
>>>>>> to MailMessage>>to:
>>>>>> 
>>>>>> =============== Diff against Collections-eem.755 ===============
>>>>>> 
>>>>>> Item was added:
>>>>>> + ----- Method: SequenceableCollection>>withoutDuplicates (in
>>>>>> category 'copying') -----
>>>>>> + withoutDuplicates
>>>>>> +       "Answer a copy of the receiver that preserves order but
>>>>>> eliminates any duplicates."
>>>>>> +       | seen |
>>>>>> +       seen := Set new: self size.
>>>>>> +       ^self select: [:each|
>>>>>> +                                 (seen includes: each)
>>>>>> +                                       ifTrue: [false]
>>>>>> +                                       ifFalse: [seen add: each.
>>>>>> true]]!
>>>>>> 
>>>>>> What a great opportunity to use #addNewElement::
>>>>>> 
>>>>>>        ^self select: [ :each | seen addNewElement: each ]
>>>>>> 
>>>>>> I love the functionality but I don't like the selector. It seems to
>>>>>> imply that one must only add a new element.  So why not call this something
>>>>>> like addIfAbsent: ?
>>>>>> 
>>>>>> Here are some suggestions.  Votes?
>>>>>> - don't change it; stick with addNewElement:
>>>>>> - addIfAbsent:
>>>>>> - ifAbsentAdd:
>>>>>> - ifMissingAdd:
>>>>>> 
>>>>>> I think I prefer ifAbsentAdd: cuz addIfAbsent: looks too much like a
>>>>>> potential spelling error, and conflicts with typical ifAbsent: arguments
>>>>>> supplying exception blocks.  But I could go with ifMissingAdd: because it is
>>>>>> more distinctive.
>>>>> 
>>>>> Well, we do have
>>>>> 
>>>>>        Collection>>addIfNotPresent:
>>>>> 
>>>>> So why invent a new one?
>>>>> 
>>>>> Because addIfNotPresent: answers its argument and we need one that
>>>>> answers whether the element was absent.  So alas addIfNotPresent: is not a
>>>>> suitable candidate.
>>>>> 
>>>>> 
>>>>> I think the important thing with #addNewElement: is that it returns
>>>>> *whether* it added a new element
>>>>> but then again it breaks the tradition of #add* returning its
>>>>> argument…
>>>>> 
>>>>> a very clear and very strange one that would reveal that a boolean is
>>>>> returned would be #isAbsentAndIfSoAdd: …
>>>>> 
>>>>> wasAbsentAdding: or ifWasAbsentAdding: would be less cumbersome but I
>>>>> like something snappier that people will remember.  ifMissingAdd: looks good
>>>>> because it doesn't conflict with the add*: methods answering their argument,
>>>>> and the ifMissing implies the answer is true if the element wasn't already
>>>>> present.
>>>>> 
>>>>> Stéphane, can you live with ifMissingAdd: ?  Chris?
>>>>> 
>>>>> Best regards
>>>>>        -Tobias
>>>>> 
>>>>>> _,,,^..^,,,_
>>>>>> best, Eliot
>>>>> 
>>>>> _,,,^..^,,,_
>>>>> best, Eliot
>>>> 
>>>> _,,,^..^,,,_
>>>> best, Eliot
>>>> 
>>> 
>>> 
>> 
>> 
>> 
>> 
>