[squeak-dev] The Trunk: Regex-Core-pre.51.mcz
Nicolas Cellier
nicolas.cellier.aka.nice at gmail.com
Fri May 20 06:41:32 UTC 2016
2016-05-19 23:21 GMT+02:00 Rein, Patrick <Patrick.Rein at hpi.de>:
> Hi Nicolas,
>
>
> thanks for looking into this, as this is kind of tricky to get right on my
> own without any discussions. What I did is to look into the value of
> anRmxLink in #makeQuantified:min:max: before and after a copy. What happens
> is that the backward references in RxmBranch nodes back to other RxmLink
> nodes break as the references get only copied separately and result in two
> different objects. As a result the copied structure does not include any
> back references. The postCopy callbacks do not solve that issue but do, to
> my understanding at that point, only implement the recursion of the
> copying. veryDeepCopy however produces the same node structure which is
> what is actually needed for the quantified structures. This way the
> termiateWith: method works correctly and the generating of broken matcher
> structures is fixed. However, it changes the behavior slightly (as in the
> Regex-Tests-Core commit in the inbox) so I am not yet sure whether this is
> only a technical fix or also a correct fix of the behavior.
>
>
> Does that sound somewhat reasonable? :)
>
>
> Bests
>
> Patrick
>
>
> Perfectly, i missed that point, thanks for explanations.
Still, copy should do something correct and i prefer the solution posted by
Levente, even if it may sound more heavy than a clever veryDeepCopy.
>
> ------------------------------
> *From:* squeak-dev-bounces at lists.squeakfoundation.org <
> squeak-dev-bounces at lists.squeakfoundation.org> on behalf of Nicolas
> Cellier <nicolas.cellier.aka.nice at gmail.com>
> *Sent:* Thursday, May 19, 2016 22:18
> *To:* The general-purpose Squeak developers list
> *Subject:* Re: [squeak-dev] The Trunk: Regex-Core-pre.51.mcz
>
> Hi Patrick,
> IMO copy should copy deep enough without the need to invoke veryDeepCopy.
> Wouldn't it be a missing postCopy in RxmLookahead?
>
> postCopy
> super postCopy.
> lookahead := lookahead copy
>
> 2016-05-19 20:49 GMT+02:00 <commits at source.squeak.org>:
>
>> Patrick Rein uploaded a new version of Regex-Core to project The Trunk:
>> http://source.squeak.org/trunk/Regex-Core-pre.51.mcz
>>
>> ==================== Summary ====================
>>
>> Name: Regex-Core-pre.51
>> Author: pre
>> Time: 19 May 2016, 8:49:05.994548 pm
>> UUID: 49e3e29a-cf96-4f42-a8f1-4af75dbb9bca
>> Ancestors: Regex-Core-ul.50
>>
>> Fixes an erroring test of RxMatcher by replacing a copy with a
>> veryDeepCopy to sustain the integrity of the RxmLink tree.
>>
>> =============== Diff against Regex-Core-ul.50 ===============
>>
>> Item was changed:
>> ----- Method: RxMatcher>>makeQuantified:min:max: (in category
>> 'private') -----
>> makeQuantified: anRxmLink min: min max: max
>> "Perform recursive poor-man's transformation of the {<min>,<max>}
>> quantifiers."
>> | aMatcher |
>>
>> "<atom>{,<max>} ==> (<atom>{1,<max>})?"
>> min = 0 ifTrue: [
>> ^ self makeOptional: (self makeQuantified: anRxmLink min:
>> 1 max: max) ].
>>
>> "<atom>{<min>,} ==> <atom>{<min>-1, <min>-1}<atom>+"
>> max ifNil: [
>> + ^ (self makeQuantified: anRxmLink min: 1 max: min-1)
>> pointTailTo: (self makePlus: anRxmLink veryDeepCopy) ].
>> - ^ (self makeQuantified: anRxmLink min: 1 max: min-1)
>> pointTailTo: (self makePlus: anRxmLink copy) ].
>>
>> "<atom>{<max>,<max>} ==> <atom><atom> ... <atom>"
>> min = max
>> ifTrue: [
>> + aMatcher := anRxmLink veryDeepCopy.
>> + (min-1) timesRepeat: [ aMatcher pointTailTo:
>> anRxmLink veryDeepCopy ].
>> - aMatcher := anRxmLink copy.
>> - (min-1) timesRepeat: [ aMatcher pointTailTo:
>> anRxmLink copy ].
>> ^ aMatcher ].
>>
>> "<atom>{<min>,<max>} ==>
>> <atom>{<min>,<min>}(<atom>{1,<max>-1})?"
>> + aMatcher := self makeOptional: anRxmLink veryDeepCopy.
>> - aMatcher := self makeOptional: anRxmLink copy.
>> (max - min - 1) timesRepeat: [
>> + aMatcher := self makeOptional: (anRxmLink veryDeepCopy
>> pointTailTo: aMatcher) ].
>> - aMatcher := self makeOptional: (anRxmLink copy
>> pointTailTo: aMatcher) ].
>> ^ (self makeQuantified: anRxmLink min: min max: min) pointTailTo:
>> aMatcher!
>>
>>
>>
>
>
>
>
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