September 2017 - Pharo-dev - lists.pharo.org

Non-deterministic ombu errors
by Gabriel Cotelli Oct. 5, 2017

Oct. 5, 2017

Hi, I'm having some non-deterministic errors in the Travis builds, the error is always something like: *OmFileStoreReadingError: Reading entry from File @ pharo-local/ombu-sessions/Pharo.4p8buz6mww48y1noxrolgwkl1.ombu@17432579: Invalid utf8 input detected* If I retried the build it works without any change. I think it happens during the code loading phase. Is anyone experiencing this issue? Here's an extract of the travis log: *OmFileStoreReadingError: Reading entry from File @ pharo-local/ombu-sessions/Pharo.4p8buz6mww48y1noxrolgwkl1.ombu@17432579: Invalid utf8 input detected* [ :error | (OmFileStoreReadingError readingError: error on: self fileReference position: readStream position) signal ] in [ :readStream | [ ^ aBlockClosure value: readStream ascii ] on: Error do: [ :error | (OmFileStoreReadingError readingError: error on: self fileReference position: readStream position) signal ] ] in OmBlockFileStore(OmFileStore)>>readEntriesWith: in Block: [ :error | ... BlockClosure>>cull: Context>>evaluateSignal: Context>>handleSignal: UTF8InvalidText(Exception)>>signal UTF8InvalidText(Exception)>>signal: UTF8TextConverter>>errorMalformedInput UTF8TextConverter>>nextFromStream: MultiByteFileStream>>next MultiByteFileStream(PositionableStream)>>match: MultiByteFileStream(PositionableStream)>>upToAll: OmSTONEntryReader>>nextEntryPositionIfFound:ifNone: OmBlockFileStore>>refreshNewBlocksFrom: [ :readStream | self refreshNewBlocksFrom: readStream ] in OmBlockFileStore>>refreshEntryPositionsByLocalNameStartingAt:since: in Block: [ :readStream | self refreshNewBlocksFrom: readStr...etc... [ ^ aBlockClosure value: readStream ascii ] in [ :readStream | [ ^ aBlockClosure value: readStream ascii ] on: Error do: [ :error | (OmFileStoreReadingError readingError: error on: self fileReference position: readStream position) signal ] ] in OmBlockFileStore(OmFileStore)>>readEntriesWith: in Block: [ ^ aBlockClosure value: readStream ascii ] BlockClosure>>on:do: [ :readStream | [ ^ aBlockClosure value: readStream ascii ] on: Error do: [ :error | (OmFileStoreReadingError readingError: error on: self fileReference position: readStream position) signal ] ] in OmBlockFileStore(OmFileStore)>>readEntriesWith: in Block: [ :readStream | ... [ aBlock value: stream ] in FileReference(AbstractFileReference)>>readStreamDo: in Block: [ aBlock value: stream ] BlockClosure>>ensure: FileReference(AbstractFileReference)>>readStreamDo: OmBlockFileStore(OmFileStore)>>readEntriesWith: OmBlockFileStore>>refreshEntryPositionsByLocalNameStartingAt:since: [ | initialPosition initialLocalName | self entryBuffer isEmpty ifTrue: [ ^ self ]. fileReference writeStreamDo: [ :fileStream | fileStream setToEnd. initialPosition := fileStream position. initialLocalName := self entryBuffer first value. ZnBufferedWriteStream on: fileStream do: [ :aWriteStream | | anEntryWriter | anEntryWriter := self newEntryWriter. [ self entryBuffer isEmpty ] whileFalse: [ | next entry | next := self entryBuffer removeFirst. entry := next key. "Write entry to file" anEntryWriter on: aWriteStream nextEntryPut: entry ] ]. "In Linux it was necessary to explicitely flush the file stream" fileStream flush. lastStreamPosition := fileStream size ]. self refreshEntryPositionsByLocalNameStartingAt: initialPosition since: initialLocalName ] in OmBlockFileStore(OmFileStore)>>flushEntryBuffer in Block: [ | initialPosition initialLocalName |... [ caught := true. self wait. blockValue := mutuallyExcludedBlock value ] in Semaphore>>critical: in Block: [ caught := true.... BlockClosure>>ensure: Semaphore>>critical: OmBlockFileStore(OmFileStore)>>critical: OmBlockFileStore(OmFileStore)>>flushEntryBuffer OmDeferrer>>sendMessage [ self sendMessage ] in OmDeferrer>>flush in Block: [ self sendMessage ]

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String Interpolation
by Sven Van Caekenberghe Oct. 4, 2017

Oct. 4, 2017

Hi, I got into a little office discussion about string interpolation as it is done in different programming languages. In Pharo we have String>>#format: which is pretty nice. It works as follows: | x y | x := 123. y := #foo. 'x={1} and y={2}' format: { x. y }. It is also possible to use a dictionary with keys, like this: | x y | x := 123. y := #foo. 'x={x} and y={y}' format: { #x->x. #y->y } asDictionary. But this is not true string interpolation as described in [ https://en.wikipedia.org/wiki/String_interpolation ]. The idea is to write the value generating expressions directly inside the strings. Since in Pharo we add features not by extending the syntax but by adding messages I wondered if it could be done for string interpolation. The goal is to make the following work: | x y | x := 123. y := #foo. 'It seems x equals {x} and y equals {y} while Pi is still {Float pi}' interpolate. => 'It seems x equals 123 and y equals foo while Pi is still 3.141592653589793' Here is the implementation I came up with: String>>#interpolate "Format the receiver by interpolating the evaluation of expressions in between curly brackets in the context of the sender as in the following 3 oneline examples. 'Today is {Date today}' interpolate. | x | x := 123. 'x equals {x} and pi equals {Float pi}' interpolate. 'In {#strings} you can escape \{ by prefixing it with \\' interpolate." | senderContext | senderContext := thisContext sender. ^ self class new: self size streamContents: [ :out | | stream | stream := self readStream. [ stream atEnd ] whileFalse: [ | currentChar | (currentChar := stream next) == ${ ifTrue: [ | expression result | expression := stream upTo: $}. result := Compiler new evaluate: expression in: senderContext to: nil notifying: nil ifFail: [ ^ nil ] logged: false. out nextPutAll: result asString ] ifFalse: [ currentChar == $\ ifTrue: [ stream atEnd ifFalse: [ out nextPut: stream next ] ] ifFalse: [ out nextPut: currentChar ] ] ] ] It is a hack that could certainly be improved. And there is of course an obvious security problem. Thoughts ? Sven

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Scraping HTML chapter 2 (soon chapter 3 coming)
by Stephane Ducasse Oct. 4, 2017

Oct. 4, 2017

I came with the idea of this booklet thank to Peter Kenny that kindly answered a question on the Pharo mailing-list. To help, Peter showed to a Pharoer how to scrap a web site using XPath. In addition, some years ago I was maintaining Soup a scraping framework because I was scraping magic web sites and I wanted an application to manage my magic cards. Since then I always wanted to try XPath and in addition I wanted to offer this booklet to Peter. Why because I asked Peter if he would like to write something and he told that he was at a great age where he would not take any commitment. I realised that I would like to get as old as him and be able to hack like a mad in Pharo with new technology. So this booklet is a gift to Peter, a great and gentle Pharoer. Stef

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[Ann] Class meta annotations
by Denis Kudriashov Oct. 4, 2017

Oct. 4, 2017

Hi. I glad to present one class package which introduces reusable mechanism for first class annotations. The project can be found on github https://github.com/dionisiydk/ClassMetaAnnotation. And I tried to describe why it is needed in my blog http://dionisiydk.blogspot.fr/2017/09/class-meta-annotations.html. And here is overview: Every annotation should be subclass of ClassMetaAnnotation. To attach it to class you create new class side method which will return an instance of the annotation. Method should be marked with pragma #classMetaAnnotation: MyClass class>>specialAnnotation <classMetaAnnotation> ^MySpecialAnnotation new To query annotations from system there are two methods: 1) You can ask concrete annotation class for all declared instances: MySpecialAnnotation declaredInstances 2) You can ask given class for all attached annotations: MyClass metaAnnotations Every annotation includes information about annotated class and the selector of declaring method. All annotations are cached. So it is cheap to query them. There are extra messages to enumerate annotations using block. Now let's discuss it. I think it can be good addition for the Pharo 7. Especially that it is very small code. Also I would like to thank Marcus who helps me realize this concept in Commander and Calypso which I start simplify with this library. Best regards, Denis

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Should we always put application file paths into FileLocator?
by Denis Kudriashov Oct. 3, 2017

Oct. 3, 2017

Hi. Many times I was trying to find "global" files of some packages in system. For example do you know how to find epicea session logs? There is class side method for this at EpMonitor: EpMonitor logsDirectory Is it easy to find when you never look at it? No. Do you know how to find sources file? There is message in Smalltalk global: Smalltalk sourcesFile Is it easy to find? No. And there are many other examples. But if you read about FileSystem library. You know the common place where to find well known files. It is FileLocator. For example changes file is here: FileLocator changes. So my idea is to introduce kind of pattern, the good style, how to access global application files: they should be in FileLocator as extensions. Then it would be super easy to find files of any applications. What do you think? If it is good idea then we should fix current places in system to follow this pattern. Best regards, Denis

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About a discord channel for the mooc?
by Stephane Ducasse Oct. 3, 2017

Oct. 3, 2017

Hi guys The students of the lectures at Prague and the forthcoming mooc will be strongly suggested to use discord. So now how can we organise it? How do we create a channel? Stef

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Two GitHub organizations
by Sean P. DeNigris Oct. 2, 2017

Oct. 2, 2017

What is the difference between pharo-project and pharo-vcs? ----- Cheers, Sean -- Sent from: http://forum.world.st/Pharo-Smalltalk-Developers-f1294837.html

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Iceberg Contribution Barrier
by Sean P. DeNigris Oct. 2, 2017

Oct. 2, 2017

I wanted to make a fix to Iceberg. I downloaded a fresh Pharo 7.0 image via Launcher, and pasted the Iceberg updating script from the GH readme [1]: #('Iceberg-UI' 'Iceberg-Plugin-GitHub' 'Iceberg-Plugin' 'Iceberg-Metacello-Integration' 'Iceberg-Libgit' 'Iceberg' 'BaselineOfIceberg' 'LibGit-Core' 'BaselineOfLibGit') do: [ :each | each asPackage removeFromSystem ]. Metacello new baseline: 'Iceberg'; repository: 'github://pharo-vcs/iceberg'; load. I got "Instance of AnObsoleteIceMetacelloRepositoryAdapter did not understand #isValid" 1. https://github.com/seandenigris/iceberg ----- Cheers, Sean -- Sent from: http://forum.world.st/Pharo-Smalltalk-Developers-f1294837.html

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people on discord are asking were is the wiki to list projects?
by Stephane Ducasse Oct. 1, 2017

Oct. 1, 2017

2 1

Iceberg question
by Gabriel Cotelli Sept. 30, 2017

Sept. 30, 2017

Hi, I've started a new and empty repository and noticed that after adding some code the .filetree file generated by Iceberg on Sync is not commited. Is this file necessary or I can just ignore it? Thanks, Gabriel

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