April 2022 - Pharo-users - lists.pharo.org

Loading from a git repository with Metacello on a running seaside image

by Emilio Oca

Hi List I need some help with Metacello, and may be git too I would like to be able to, in a running headless image, load the last commit of a git repo Something like Metacello new baseline:'MyProject'; repository: 'github://myUser/MyProject:main/myProject'; load. works just once and may open some dialogs Something like this [ [ Metacello new baseline:'MyProject'; repository: 'github://myUser/MyProject:main/myProject'; onConflictUseIncoming; load. ] on: MetacelloSkipDirtyPackageLoad do: [ :ex | ex resume: false ]. ] on: MCMergeOrLoadWarning do: [ :ex | ex load ]. Avoids the dialogs and alerts but the code is still not updated. My intention is to be able to 'refresh' a running seaside image with its latest development version from a git repo (avoiding to personally reach the server and rebuild the docker image) What am I missing? Best Emilio

April 23, 2022

Re: A question about #beginsWith: and #endsWith:

by Richard O'Keefe

Dan Ingalls is of course a big NAME in the world of Smalltalk, but the stated reason for changing the behaviour of #beginsWith: and #endsWith: makes no sense. We have many ways to define a partial order on strings. x <= y iff y beginsWith: x x <= y iff y endsWith: x x <= y iff y includesSubCollection: x x <= y iff y includesSubSequence: x These things are supposed to obey laws: if a beginsWith: b , c then a beginsWith: b if a endsWith: b , c then a endsWith: c if a includesSubCollection: b , c then a includesSubCollection: b and a includesSubCollection: c if a includesSubSequence: b , c then a includesSubSequence: b and a includesSubSequence: c. We also expect the usual rules of equality to hold. So (1) a beginsWith: a (2) a = '' , a (3) THEREFORE a beginsWith: '' (1) a endsWith: a (2) a = a , '' (3) THEREFORE a endsWith: '' (1) a includesSubCollection: a (2) a = '' , a (3) THEREFORE a includesSubCollect: '' Reasoning about strings (as values) gets enormously more complicated if the operations do not follow simple sensible rules, and having '' be the least string under these orderings and having '' be a prefix and a suffix of any string is essential if the rules are going to be simple and coherent. '' is to strings (and more generally empty sequences are to sequences) pretty much what 0 is to integers. Denying that 'abc' beginsWith: '' is *structurally* just like denying that 0 <= 123. Now as it happens I *can* see a use for versions of #beginsWith: and #endsWith: that diverge from the ones we have, but *this* is not where they need to diverge. a beginsWithGraphemesOf: b iff a asGraphemes = b asGraphemes , c asGraphemes for some c, where s asGraphemes returns a sequence of strings each of which is a maximally long grapheme cluster, such that concatenating s asGraphemes recovers s. That is, #beginsWithGraphemesOf: and #endsWithGraphemesOf: would respect the Unicode Text Segmentation boundaries. But s beginsWithGraphemesOf: '' would still need to be true. The thing is, in practice you often DON'T KNOW whether a potential affix is empty or not. Here are some of my test cases. testTestData "Ensure that the sample string has no duplicates." [(Set withAll: string) size = stringSize] assert. testBeginsWith "Test that every prefix of the sample IS a prefix of it." 0 to: stringSize do: [:n | [string beginsWith: (string copyFrom: 1 to: n)] assert]. testEndsWith "Test that every suffix of the sample IS a suffix of it." 0 to: stringSize do: [:n | [string endsWith: (string copyFrom: stringSize - n + 1 to: stringSize)] assert]. testIndexOfSubCollectionAtBeginning "Test that every prefix of 'abcd' is found at the beginning." 0 to: stringSize do: [:n | |s i t| s := string copyFrom: 1 to: n. i := string indexOfSubCollection: s startingAt: 1. [1 = i] assert. t := string copyFrom: i to: i - 1 + n. [t = s] assert]. testIndexOfSubCollectionAtEnd "Test that every proper suffix of the sample is found at the end." 1 to: stringSize do: [:n | |s i t| s := string copyFrom: stringSize - n + 1 to: stringSize. i := string indexOfSubCollection: s startingAt: 1. [stringSize + 1 - n = i] assert. t := string copyFrom: i to: i - 1 + n. [t = s] assert]. testLastIndexOfSubCollectionAtBeginning "Test that every proper prefix of the sample is found at the beginning." 1 to: stringSize do: [:n | |s i t| s := string copyFrom: 1 to: n. i := string lastIndexOfSubCollection: s startingAt: stringSize. [1 = i] assert. t := string copyFrom: i to: i - 1 + n. [t = s] assert]. testLastIndexOfSubCollectionAtEnd "Test that every suffix of the sample is found at the end." 0 to: stringSize do: [:n | |s i t| s := string copyFrom: stringSize - n + 1 to: stringSize. i := string lastIndexOfSubCollection: s startingAt: stringSize. [stringSize + 1 - n = i] assert. t := string copyFrom: i to: i - 1 + n. [t = s] assert]. testOccurrencesOfEmptyCollection "Test that the empty string occurs at the beginning, at the end, and in between every pair of adjacent characters." [(string occurrencesOfSubCollection: '') = (stringSize + 1)] assert. testOccurrencesOfUniqueParts "Test that unique parts occur as many times as they should." |repeated| repeated := string , string , string. 1 to: stringSize do: [:start | start to: stringSize do: [:finish | |s n| s := string copyFrom: start to: finish. n := string occurrencesOfSubCollection: s. [n = 1] assert. n := repeated occurrencesOfSubCollection: s. [n = 3] assert]]. On Fri, 22 Apr 2022 at 13:57, David T. Lewis <lewis(a)mail.msen.com> wrote: > Hi Richard, > > (CC squeak-dev list, replies to the relevant list please) > > On Thu, Apr 21, 2022 at 12:07:32AM +1200, Richard O'Keefe wrote: > > I've just tracked down a nasty little problem > > porting some code to Pharo. As a result, I > > have added to the comments in my own versions > > of these methods. beginsWith: aSequence > > "Answer true if aSequence is a prefix of the receiver. > > This makes sense for all sequences. > > There is a compatibility issue concerning 'abc' beginsWith: '' > > + VisualWorks, Dolphin, astc, GNU ST (where the method is > > called #startsWith:) and VisualAge (where the method > > is called #wbBeginsWith:) > > agree than EVERY sequence begins with an empty prefix. > > - Squeak and Pharo > > agree that NO sequence begins with an empty sequence. > > # ST/X chooses compatibility with Squeak, heaving a big unhappy > > sigh, and adds #startsWith: to have something sensible to use. > > Now ST/X *thinks* it is compatible with VW, though it isn't, so > > I wonder if this was a bug that VW fixed and Squeak didn't? > > astc goes with the majority here. This is also compatible with > > Haskell, ML, and with StartsWith in C# and startsWith in Java." > > ^self beginsWith: aSequence ignoringCase: false > > > > endsWith: aSequence > > "Answer true if aSequence is a suffix of the receiver. > > This makes sense for all sequences. > > There is a compatibility issue concerning 'abc' endsWith: ''. > > + VisualWorks, Dolphin, astc, GNU ST, and VisualAge (where > > the method is called #wbEndsWith:) > > agree that EVERY sequence ends with an empty suffix. > > - Squeak and Pharo > > agree that NO sequence ends with an empty suffix. > > # ST/X chooses compatibility with the majority, apparently > > unaware that this makes #beginsWith: and #endsWith: > inconsistent. > > astc goes with the majority here. This is also compatible with > > Haskell, ML, C#, and Java." > > ^self endsWith: aSequence ignoringCase: false > > > > Does anyone have any idea > > - why Squeak and Pharo are the odd ones out? > > - why anyone thought making #beginsWith: and #endsWith:, um, "quirky" > > was a good idea (it's pretty standard in books on the theory of > > strings to define "x is a prefix of y iff there is a z such that > > y = x concatenated with z") > > The Squeak behavior was introduced in November 1998 by Dan Ingalls > in conjunction with some VM improvements that he was doing, and was > included in the Squeak2.2 release at that time. > > Prior to that update, Squeak did this: > 'abc' beginsWith: '' ==> true > 'abc' endsWith: '' ==> true > > For Squeak2.2 and later it is: > 'abc' beginsWith: '' ==> false > 'abc' endsWith: '' ==> false > > Pharo presumably inherits this from Squeak. > > I am attaching Dan's original change set from the early Squeak > update stream so you can see the context. > > The change set comment says that "endsWith:, beginsWith:, and match > have been rewritten to take advantage of this considerably faster method" > (referring to a new primitive that Dan had added to the VM in this > change set). > > > > > I was about to try to file a bug report for the first time, > > then realised that maybe other people don't think this IS a bug. > > I don't think it is a bug. I can't think of a case where it makes > sense to say that a string of characters "begins with" or "ends with" > a string that contains nothing. > > In any case, that's the history of the change in Squeak and Pharo as > best as I can reconstruct it. > > HTH, > Dave > >

April 23, 2022

Re: A question about #beginsWith: and #endsWith:

by David T. Lewis

Hi Richard, (CC squeak-dev list, replies to the relevant list please) On Thu, Apr 21, 2022 at 12:07:32AM +1200, Richard O'Keefe wrote: > I've just tracked down a nasty little problem > porting some code to Pharo. As a result, I > have added to the comments in my own versions > of these methods. beginsWith: aSequence > "Answer true if aSequence is a prefix of the receiver. > This makes sense for all sequences. > There is a compatibility issue concerning 'abc' beginsWith: '' > + VisualWorks, Dolphin, astc, GNU ST (where the method is > called #startsWith:) and VisualAge (where the method > is called #wbBeginsWith:) > agree than EVERY sequence begins with an empty prefix. > - Squeak and Pharo > agree that NO sequence begins with an empty sequence. > # ST/X chooses compatibility with Squeak, heaving a big unhappy > sigh, and adds #startsWith: to have something sensible to use. > Now ST/X *thinks* it is compatible with VW, though it isn't, so > I wonder if this was a bug that VW fixed and Squeak didn't? > astc goes with the majority here. This is also compatible with > Haskell, ML, and with StartsWith in C# and startsWith in Java." > ^self beginsWith: aSequence ignoringCase: false > > endsWith: aSequence > "Answer true if aSequence is a suffix of the receiver. > This makes sense for all sequences. > There is a compatibility issue concerning 'abc' endsWith: ''. > + VisualWorks, Dolphin, astc, GNU ST, and VisualAge (where > the method is called #wbEndsWith:) > agree that EVERY sequence ends with an empty suffix. > - Squeak and Pharo > agree that NO sequence ends with an empty suffix. > # ST/X chooses compatibility with the majority, apparently > unaware that this makes #beginsWith: and #endsWith: inconsistent. > astc goes with the majority here. This is also compatible with > Haskell, ML, C#, and Java." > ^self endsWith: aSequence ignoringCase: false > > Does anyone have any idea > - why Squeak and Pharo are the odd ones out? > - why anyone thought making #beginsWith: and #endsWith:, um, "quirky" > was a good idea (it's pretty standard in books on the theory of > strings to define "x is a prefix of y iff there is a z such that > y = x concatenated with z") The Squeak behavior was introduced in November 1998 by Dan Ingalls in conjunction with some VM improvements that he was doing, and was included in the Squeak2.2 release at that time. Prior to that update, Squeak did this: 'abc' beginsWith: '' ==> true 'abc' endsWith: '' ==> true For Squeak2.2 and later it is: 'abc' beginsWith: '' ==> false 'abc' endsWith: '' ==> false Pharo presumably inherits this from Squeak. I am attaching Dan's original change set from the early Squeak update stream so you can see the context. The change set comment says that "endsWith:, beginsWith:, and match have been rewritten to take advantage of this considerably faster method" (referring to a new primitive that Dan had added to the VM in this change set). > > I was about to try to file a bug report for the first time, > then realised that maybe other people don't think this IS a bug. I don't think it is a bug. I can't think of a case where it makes sense to say that a string of characters "begins with" or "ends with" a string that contains nothing. In any case, that's the history of the change in Squeak and Pharo as best as I can reconstruct it. HTH, Dave

April 22, 2022

[ANN] Stargate v8.1.1 [v8.1.1] released!

by Buenos Aires Smalltalk

April 21, 2022

UK Smalltalk User Group Meeting - Wednesday, April 27th

by Giovanni Corriga

The next meeting of the UK Smalltalk User Group will be held on Wednesday, April 27th 2022. Newspeak ( https://bracha.org/Site/Newspeak.html ) is a programming system in the Smalltalk tradition, whose current incarnation runs in the web browser. Newspeak is designed to provide the liveness Smalltalkers expect, as well as features atypical of Smalltalk such as modularity, security and good interoperability with the surrounding ecosystem. In this talk, we'll explain how and why Newspeak differs from Smalltalk and demonstrate the Newspeak IDE. Gilad Bracha is the creator of the Newspeak programming language and a well known researcher in the area of object-oriented programming languages. He was awarded the senior Dahl-Nygaard prize in 2017. He is currently a Technical Fellow at F5, and has held positions at Google, SAP Labs, Cadence, and Sun. He has authored or co-authored several books including the Java Language and Virtual Machine Specifications, and the Dart Programming Language. Prior to joining Sun, he worked on Strongtalk, the Animorphic Smalltalk System. He received his B.Sc in Mathematics and Computer Science from Ben Gurion University in Israel and a Ph.D. in Computer Science from the University of Utah. This will be an online meeting from home. If you'd like to join us, please sign up in advance on the meeting's Meetup page ( https://www.meetup.com/UKSTUG/events/cbklbrydcgbkc/ ) to receive the meeting details. Donât forget to bring your laptop and drinks!

April 20, 2022

Re: A question about #beginsWith: and #endsWith:

by Sven Van Caekenberghe

Since 'abc' includesSubstring: ''. "true" 'abc' indexOfSubCollection: ''. "0" and following basic principles, my first reaction would also be that 'abc' beginsWith: ''. 'abc' endsWith: ''. should both be true. On the other hand, this is really a degenerate case. You know the answer upfront (it does not depend on the actual receiver) and thus it does not tell you much. I vote for this to be a bug. > On 20 Apr 2022, at 14:07, Richard O'Keefe <raoknz(a)gmail.com> wrote: > > I've just tracked down a nasty little problem > porting some code to Pharo. As a result, I > have added to the comments in my own versions > of these methods. beginsWith: aSequence > "Answer true if aSequence is a prefix of the receiver. > This makes sense for all sequences. > There is a compatibility issue concerning 'abc' beginsWith: '' > + VisualWorks, Dolphin, astc, GNU ST (where the method is > called #startsWith:) and VisualAge (where the method > is called #wbBeginsWith:) > agree than EVERY sequence begins with an empty prefix. > - Squeak and Pharo > agree that NO sequence begins with an empty sequence. > # ST/X chooses compatibility with Squeak, heaving a big unhappy > sigh, and adds #startsWith: to have something sensible to use. > Now ST/X *thinks* it is compatible with VW, though it isn't, so > I wonder if this was a bug that VW fixed and Squeak didn't? > astc goes with the majority here. This is also compatible with > Haskell, ML, and with StartsWith in C# and startsWith in Java." > ^self beginsWith: aSequence ignoringCase: false > > endsWith: aSequence > "Answer true if aSequence is a suffix of the receiver. > This makes sense for all sequences. > There is a compatibility issue concerning 'abc' endsWith: ''. > + VisualWorks, Dolphin, astc, GNU ST, and VisualAge (where > the method is called #wbEndsWith:) > agree that EVERY sequence ends with an empty suffix. > - Squeak and Pharo > agree that NO sequence ends with an empty suffix. > # ST/X chooses compatibility with the majority, apparently > unaware that this makes #beginsWith: and #endsWith: inconsistent. > astc goes with the majority here. This is also compatible with > Haskell, ML, C#, and Java." > ^self endsWith: aSequence ignoringCase: false > > Does anyone have any idea > - why Squeak and Pharo are the odd ones out? > - why anyone thought making #beginsWith: and #endsWith:, um, "quirky" > was a good idea (it's pretty standard in books on the theory of > strings to define "x is a prefix of y iff there is a z such that > y = x concatenated with z") > > I was about to try to file a bug report for the first time, > then realised that maybe other people don't think this IS a bug. > > >

April 20, 2022

Re: A question about #beginsWith: and #endsWith:

by Kasper Osterbye

Yes, that one I have come across several times - even without trying to port anything, merely because it is how beginsWith: should work (supporting the empty string). I have no idea about the rationale though. Best, Kasper > On 20 Apr 2022, at 14.07, Richard O'Keefe <raoknz(a)gmail.com> wrote: > > I've just tracked down a nasty little problem > porting some code to Pharo. As a result, I > have added to the comments in my own versions > of these methods. beginsWith: aSequence > "Answer true if aSequence is a prefix of the receiver. > This makes sense for all sequences. > There is a compatibility issue concerning 'abc' beginsWith: '' > + VisualWorks, Dolphin, astc, GNU ST (where the method is > called #startsWith:) and VisualAge (where the method > is called #wbBeginsWith:) > agree than EVERY sequence begins with an empty prefix. > - Squeak and Pharo > agree that NO sequence begins with an empty sequence. > # ST/X chooses compatibility with Squeak, heaving a big unhappy > sigh, and adds #startsWith: to have something sensible to use. > Now ST/X *thinks* it is compatible with VW, though it isn't, so > I wonder if this was a bug that VW fixed and Squeak didn't? > astc goes with the majority here. This is also compatible with > Haskell, ML, and with StartsWith in C# and startsWith in Java." > ^self beginsWith: aSequence ignoringCase: false > > endsWith: aSequence > "Answer true if aSequence is a suffix of the receiver. > This makes sense for all sequences. > There is a compatibility issue concerning 'abc' endsWith: ''. > + VisualWorks, Dolphin, astc, GNU ST, and VisualAge (where > the method is called #wbEndsWith:) > agree that EVERY sequence ends with an empty suffix. > - Squeak and Pharo > agree that NO sequence ends with an empty suffix. > # ST/X chooses compatibility with the majority, apparently > unaware that this makes #beginsWith: and #endsWith: inconsistent. > astc goes with the majority here. This is also compatible with > Haskell, ML, C#, and Java." > ^self endsWith: aSequence ignoringCase: false > > Does anyone have any idea > - why Squeak and Pharo are the odd ones out? > - why anyone thought making #beginsWith: and #endsWith:, um, "quirky" > was a good idea (it's pretty standard in books on the theory of > strings to define "x is a prefix of y iff there is a z such that > y = x concatenated with z") > > I was about to try to file a bug report for the first time, > then realised that maybe other people don't think this IS a bug. > > >

April 20, 2022

A question about #beginsWith: and #endsWith:

by Richard O'Keefe

I've just tracked down a nasty little problem porting some code to Pharo. As a result, I have added to the comments in my own versions of these methods. beginsWith: aSequence "Answer true if aSequence is a prefix of the receiver. This makes sense for all sequences. There is a compatibility issue concerning 'abc' beginsWith: '' + VisualWorks, Dolphin, astc, GNU ST (where the method is called #startsWith:) and VisualAge (where the method is called #wbBeginsWith:) agree than EVERY sequence begins with an empty prefix. - Squeak and Pharo agree that NO sequence begins with an empty sequence. # ST/X chooses compatibility with Squeak, heaving a big unhappy sigh, and adds #startsWith: to have something sensible to use. Now ST/X *thinks* it is compatible with VW, though it isn't, so I wonder if this was a bug that VW fixed and Squeak didn't? astc goes with the majority here. This is also compatible with Haskell, ML, and with StartsWith in C# and startsWith in Java." ^self beginsWith: aSequence ignoringCase: false endsWith: aSequence "Answer true if aSequence is a suffix of the receiver. This makes sense for all sequences. There is a compatibility issue concerning 'abc' endsWith: ''. + VisualWorks, Dolphin, astc, GNU ST, and VisualAge (where the method is called #wbEndsWith:) agree that EVERY sequence ends with an empty suffix. - Squeak and Pharo agree that NO sequence ends with an empty suffix. # ST/X chooses compatibility with the majority, apparently unaware that this makes #beginsWith: and #endsWith: inconsistent. astc goes with the majority here. This is also compatible with Haskell, ML, C#, and Java." ^self endsWith: aSequence ignoringCase: false Does anyone have any idea - why Squeak and Pharo are the odd ones out? - why anyone thought making #beginsWith: and #endsWith:, um, "quirky" was a good idea (it's pretty standard in books on the theory of strings to define "x is a prefix of y iff there is a z such that y = x concatenated with z") I was about to try to file a bug report for the first time, then realised that maybe other people don't think this IS a bug.

April 20, 2022

[ANN] RenoirSt v7.1.0 [v7.1.0] released!

by Buenos Aires Smalltalk

April 20, 2022

[ANN] Cannon v1.1.0 [v1.1.0] released!

by Buenos Aires Smalltalk

April 19, 2022