The Inbox: Collections-jar.924.mcz

> A new version of Collections was added to project The Inbox:
> http://source.squeak.org/inbox/Collections-jar.924.mcz
>
> ==================== Summary ====================
>
> Name: Collections-jar.924
> Author: jar
> Time: 7 February 2021, 9:42:07.649004 am
> UUID: 073b26bc-8e5e-ba41-9aac-9d424bbe6848
> Ancestors: Collections-dtl.923
>
> Fixes SharedQueue >> nextOrNilSuchThat bug to pass the existing test
>
> =============== Diff against Collections-dtl.923 ===============
>
> Item was changed:
>   ----- Method: SharedQueue>>nextOrNilSuchThat: (in category 'accessing') -----
>   nextOrNilSuchThat: aBlock
>   "Answer the next object that satisfies aBlock, skipping any intermediate objects.
>   If no object has been sent, answer <nil> and leave me intact.
>   NOTA BENE:  aBlock MUST NOT contain a non-local return (^)."
>  
>   ^accessProtect critical: [
>   | value readPos |
>   value := nil.
>   readPos := readPosition.
>   [ readPos < writePosition and: [ value isNil ] ] whileTrue: [
>   value := contentsArray at: readPos.
>   readPos := readPos + 1.
>   (aBlock value: value)
>   ifFalse: [ value := nil ]
>   ifTrue: [
>   readSynch waitIfLocked: [ ^nil ]. "We found the value, but someone else booked it."
> + readPos-1 to: readPosition+1 by: -1 do: [ :j | contentsArray at: j put: (contentsArray at: j-1) ].
> + contentsArray at: readPosition put: nil.
> + readPosition := readPosition+1 ] ].
> - readPosition to: readPos - 1 do: [ :j | contentsArray at: j put: nil ].
> - readPosition := readPos ] ].
>   value ].
>   "===
>   q := SharedQueue new.
>   1 to: 10 do: [ :i | q nextPut: i].
>   c := OrderedCollection new.
>   [
>   v := q nextOrNilSuchThat: [ :e | e odd].
>   v notNil
>   ] whileTrue: [
>   c add: {v. q size}
>   ].
>   {c. q} explore
>   ==="!
>
>

>
> Thanks Jaromir for putting this in the inbox :-)
>
> Dave
>
>
> On Sun, Feb 07, 2021 at 08:42:11AM +0000, [hidden email] wrote:
>> A new version of Collections was added to project The Inbox:
>> http://source.squeak.org/inbox/Collections-jar.924.mcz
>>
>> ==================== Summary ====================
>>
>> Name: Collections-jar.924
>> Author: jar
>> Time: 7 February 2021, 9:42:07.649004 am
>> UUID: 073b26bc-8e5e-ba41-9aac-9d424bbe6848
>> Ancestors: Collections-dtl.923
>>
>> Fixes SharedQueue >> nextOrNilSuchThat bug to pass the existing test
>>
>> =============== Diff against Collections-dtl.923 ===============
>>
>> Item was changed:
>>   ----- Method: SharedQueue>>nextOrNilSuchThat: (in category 'accessing') -----
>>   nextOrNilSuchThat: aBlock
>>   "Answer the next object that satisfies aBlock, skipping any intermediate objects.
>>   If no object has been sent, answer <nil> and leave me intact.
>>   NOTA BENE:  aBlock MUST NOT contain a non-local return (^)."
>>
>>   ^accessProtect critical: [
>>   | value readPos |
>>   value := nil.
>>   readPos := readPosition.
>>   [ readPos < writePosition and: [ value isNil ] ] whileTrue: [
>>   value := contentsArray at: readPos.
>>   readPos := readPos + 1.
>>   (aBlock value: value)
>>   ifFalse: [ value := nil ]
>>   ifTrue: [
>>   readSynch waitIfLocked: [ ^nil ]. "We found the value, but someone else booked it."
>> + readPos-1 to: readPosition+1 by: -1 do: [ :j | contentsArray at: j put: (contentsArray at: j-1) ].
>> + contentsArray at: readPosition put: nil.
>> + readPosition := readPosition+1 ] ].
>> - readPosition to: readPos - 1 do: [ :j | contentsArray at: j put: nil ].
>> - readPosition := readPos ] ].
>>   value ].
>>   "===
>>   q := SharedQueue new.
>>   1 to: 10 do: [ :i | q nextPut: i].
>>   c := OrderedCollection new.
>>   [
>>   v := q nextOrNilSuchThat: [ :e | e odd].
>>   v notNil
>>   ] whileTrue: [
>>   c add: {v. q size}
>>   ].
>>   {c. q} explore
>>   ==="!
>>
>>

> Hi David,
>
> On Sun, 7 Feb 2021, David T. Lewis wrote:
>
> >This looks good to me, and it fixes the failing test.
> >
> >Note that none of the historical versions of
> >SharedQueue>>nextOrNilSuchThat:
> >pass the test, but the issue became visible after CollectionsTests-eem.342
> >last September when the existing test for SharedQueue2 was applied to
> >SharedQueue as well.
> >
> >It would be good if Levente or Nicolas can review this, but +1 from me.
>
> The fix looks right in the sense that it does what the test case requires.
> But it may affect the way events are processed.
> The only sender of this method is EventSensor which may rely on the
> current behavior.
> So, I would like someone who understands how EventSensor works confirm
> that the change is okay before pushing it to the Trunk.
>