June 2017 - Pharo-users - lists.pharo.org

Re: [Pharo-users] Wiring objects, IoC and Service Locator

by Vitor Medina Cruz

Thanks for the answer Ben and Stephane. I already read A Mentoring Course on Smalltalk, Valloud, there is nothing there I could use in this case :( . I will look after for The Design Patterns Smalltalk Companion. Most of the sources provided I already know of or went in the same lines lines of what I have already found. About TDD, I am experienced with the discipline and have tested it on Pharo living system already, but I could not understand how this is related with object wiring, DI and service locator. >From ben: "I'm not really familiar with IoC or DI patterns, so just taking your > example at face value, in Pharo I'd do... > > MovieLister>>moviesDirectedBy: director > allMovies := finder allMovies. > ^ allMovies select: [ :movie | movie getDirector = director ]. > "although typically #getDirector would be renamed #director" > > MovieLister>>finder: movieFinder > finder := movieFinder. > > to be used like this... > lister := MovieLister new finder: (ColonDelimitedMovieFinder on: > 'movies1.txt'). > movies := lister moviesDirectedBy: 'Tarantino'." and Stephane: Why don't you simply pass the class and use that class in your MovieLister? > > MovieLister new > finderClass: MySuperCoolFinderClass > > ... > MovieLister finder > finderClass new ..... > > What is wrong with that. That was what I meant when I said: "I know that in Smalltalk I can make MovieLister to receive, upon construction, a class representing MovieFinder and call it construction message.". The code I had in mind is a bit of mix from the one provided by you both: MovieLister>>moviesDirectedBy: director allMovies := finder allMovies. ^ allMovies select: [ :movie | movie getDirector = director ]. "although typically #getDirector would be renamed #director" MovieLister>>finder: aMovieFinderBuilder finder := aMovieFinderClass new. to be used like this... lister := MovieLister new finder: (ColonDelimitedMovieFinder builderOn: 'movies1.txt'). movies := lister moviesDirectedBy: 'Tarantino'." But that means I will have to wire dependencies by hand whenever I create a MovieLister and seek through code when and if those dependencies change. When there are lot's of dependencies it's is a considerable and tedious work. Let's see an image from Fowlers article: [image: Inline image 1] In this case, the service locator provides me with an instance and I configure the instance in the assembler, the scheme is alike for an IoC, and that would mean my implementation could be like this: MovieLister>>moviesDirectedBy: director allMovies := finder allMovies. ^ allMovies select: [ :movie | movie getDirector = director ]. "although typically #getDirector would be renamed #director" MovieLister>>initialize finder := ServiceLocator locate: FinderClass <--- This would bring the instance of finder class configured by the assembler to be used like this... lister := MovieLister new. movies := lister moviesDirectedBy: 'Tarantino'." and the assembler: Assember class>>configure: aMap put: (ColonDelimitedMovieFinder builderOn: 'movies1.txt') at: FinderClass My assembler and service locator could be even more elaborated, and provide a different MovieFinder in test scope, for different classes or wharever. It is a little convenience for Smalltalk, I will give that, but I was wandering if there was something alike in Pharo, by your answers I assuming there is nothing like that. If you do not want to have a reference at runtime to a Finder then you > need to use announcement and registration. I didn't understand that, could you elaborate? On Mon, Jun 5, 2017 at 6:41 AM, Stephane Ducasse <stepharo.self(a)gmail.com> wrote: > Why don't you simply pass the class and use that class in your MovieLister? > > MovieLister new > finderClass: MySuperCoolFinderClass > > ... > MovieLister finder > finderClass new ..... > > What is wrong with that. > > If you do not want to have a reference at runtime to a Finder then you > need to use announcement and registration. > > Stef > > > > On Sun, Jun 4, 2017 at 11:17 PM, Vitor Medina Cruz <vitormcruz(a)gmail.com> > wrote: > > Hello, > > > > I would like to know how people in Pharo ecosystem do to deal with object > > wiring, as described by Marting Fowler in > > https://martinfowler.com/articles/injection.html# > FormsOfDependencyInjection: > > > > "A common issue to deal with is how to wire together different elements: > how > > do you fit together this web controller architecture with that database > > interface backing when they were built by different teams with little > > knowledge of each other." > > > > He gives an example, I will leave it in java as it is simple enough to > > understand: > > > > "class MovieLister... > > > > public Movie[] moviesDirectedBy(String arg) { > > List allMovies = finder.findAll(); > > for (Iterator it = allMovies.iterator(); it.hasNext();) { > > Movie movie = (Movie) it.next(); > > if (!movie.getDirector().equals(arg)) it.remove(); > > } > > return (Movie[]) allMovies.toArray(new Movie[allMovies.size()]); > > > > }" > > > > The question is how to provide the finder object in a decoupled matter, a > > naive approach would be: > > > > " private MovieFinder finder; > > > > public MovieLister() { > > finder = new ColonDelimitedMovieFinder("movies1.txt"); > > > > }" > > > > Which couples the MovieLister to the specific ColonDelimitedMovieFinder > > class. > > > > Fowler explains how to decouple using an IoC framework or a Service > Locator. > > In Java and .Net IoC is used most of the time. I Googled how this > problem is > > approached in Smalltalk/Pharo, and I generally I found answers "that is > easy > > to do in Smalltalk, so there is no need of a framework", what I miss is a > > description on *how* to do that: > > > > https://stackoverflow.com/questions/243905/smalltalk-and-ioc > > https://stackoverflow.com/questions/2684326/is-there-a- > dependency-injection-framework-for-smalltalk > > https://stackoverflow.com/questions/243905/smalltalk- > and-ioc/347477#347477 > > > > I know that in Smalltalk I can make MovieLister to receive, upon > > construction, a class representing MovieFinder and call it construction > > message. As long an object that responds to this message is provided, I > can > > create as many derivations I want and the MovieLister will be decoupled > from > > the MovieFinder. That way, however, I still have to wire things by hand, > and > > I am not sure if this is what I am supposed to do in order to solve the > > decouple problem. > > > > Can you explain me how this is done in Pharo? It's is usually wiring by > > hand? Is there a simple construction that deals with the wiring problem > that > > I cannot foresee? > > > > Thanks in advance, > > Vitor > > > > > > > >

June 5, 2017

XPath has unresolved dependencies

by Henrik Nergaard

Hi, Loading XPath from the catalog browser into the latest image raises a warning that there are unresolved references, and that the package depends on the following classes: XMLHighlighter, XMLHighlighterDefaults, GLMXMLHighlighterTextStylerDecorator. The regular XPath works fine ignoring the warnings, but inspecting an XML document and clicking the XPath pane gives an error. Best regards, Henrik

June 5, 2017

Re: [Pharo-users] Deprecating Auto-fix: WOW

by Stephane Ducasse

:) little improvements one at a time but many many many times :) On Sat, Jun 3, 2017 at 3:32 PM, Sean P. DeNigris <sean(a)clipperadams.com> wrote: > Either I died and went to heaven, or my Pharo 6 image just ported all my > deprecated methods auto-magically. Very cool! Thanks!!! > > > > ----- > Cheers, > Sean > -- > View this message in context: http://forum.world.st/Deprecating-Auto-fix-WOW-tp4949164.html > Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com. >

June 5, 2017

Re: [Pharo-users] Wiring objects, IoC and Service Locator

by Stephane Ducasse

Why don't you simply pass the class and use that class in your MovieLister? MovieLister new finderClass: MySuperCoolFinderClass ... MovieLister finder finderClass new ..... What is wrong with that. If you do not want to have a reference at runtime to a Finder then you need to use announcement and registration. Stef On Sun, Jun 4, 2017 at 11:17 PM, Vitor Medina Cruz <vitormcruz(a)gmail.com> wrote: > Hello, > > I would like to know how people in Pharo ecosystem do to deal with object > wiring, as described by Marting Fowler in > https://martinfowler.com/articles/injection.html#FormsOfDependencyInjection: > > "A common issue to deal with is how to wire together different elements: how > do you fit together this web controller architecture with that database > interface backing when they were built by different teams with little > knowledge of each other." > > He gives an example, I will leave it in java as it is simple enough to > understand: > > "class MovieLister... > > public Movie[] moviesDirectedBy(String arg) { > List allMovies = finder.findAll(); > for (Iterator it = allMovies.iterator(); it.hasNext();) { > Movie movie = (Movie) it.next(); > if (!movie.getDirector().equals(arg)) it.remove(); > } > return (Movie[]) allMovies.toArray(new Movie[allMovies.size()]); > > }" > > The question is how to provide the finder object in a decoupled matter, a > naive approach would be: > > " private MovieFinder finder; > > public MovieLister() { > finder = new ColonDelimitedMovieFinder("movies1.txt"); > > }" > > Which couples the MovieLister to the specific ColonDelimitedMovieFinder > class. > > Fowler explains how to decouple using an IoC framework or a Service Locator. > In Java and .Net IoC is used most of the time. I Googled how this problem is > approached in Smalltalk/Pharo, and I generally I found answers "that is easy > to do in Smalltalk, so there is no need of a framework", what I miss is a > description on *how* to do that: > > https://stackoverflow.com/questions/243905/smalltalk-and-ioc > https://stackoverflow.com/questions/2684326/is-there-a-dependency-injection… > https://stackoverflow.com/questions/243905/smalltalk-and-ioc/347477#347477 > > I know that in Smalltalk I can make MovieLister to receive, upon > construction, a class representing MovieFinder and call it construction > message. As long an object that responds to this message is provided, I can > create as many derivations I want and the MovieLister will be decoupled from > the MovieFinder. That way, however, I still have to wire things by hand, and > I am not sure if this is what I am supposed to do in order to solve the > decouple problem. > > Can you explain me how this is done in Pharo? It's is usually wiring by > hand? Is there a simple construction that deals with the wiring problem that > I cannot foresee? > > Thanks in advance, > Vitor > > >

June 5, 2017

Re: [Pharo-users] Porting Transducers to Pharo

by phil＠highoctane.be

Coupling this with Olek's work on the DataFrame could really come handy. Phil On Mon, Jun 5, 2017 at 9:14 AM, Stephane Ducasse <stepharo.self(a)gmail.com> wrote: > Hi Steffen > > > > The short answer is that the compact notation turned out to work much > better > > for me in my code, especially, if multiple transducers are involved. But > > that's my personal taste. You can choose which suits you better. In fact, > > > > 1000 take. > > > > just sits on top and simply calls > > > > Take number: 1000. > > To me this is much much better. > > > > If the need arises, we could of course factor the compact notation out > into > > a separate package. > Good idea > > Btw, would you prefer (Take n: 1000) over (Take number: > > 1000)? > > I tend to prefer explicit selector :) > > > > Damien, you're right, I experimented with additional styles. Right now, > we > > already have in the basic Transducer package: > > > > (collection transduce: #squared map * 1000 take. "which is equal to" > > (collection transduce: #squared map) transduce: 1000 take. > > > > Basically, one can split #transduce:reduce:init: into single calls of > > #transduce:, #reduce:, and #init:, depending on the needs. > > I also have an (unfinished) extension, that allows to write: > > > > (collection transduce map: #squared) take: 1000. > > To me this is much mre readable. > I cannot and do not want to use the other forms. > > > > This feels familiar, but becomes a bit hard to read if more than two > steps > > are needed. > > > > collection transduce > > map: #squared; > > take: 1000. > > Why this is would hard to read. We do that all the time everywhere. > > > > I think, this alternative would reads nicely. But as the message chain > has > > to modify the underlying object (an eduction), very snaky side effects > may > > occur. E.g., consider > > > > eduction := collection transduce. > > squared := eduction map: #squared. > > take := squared take: 1000. > > > > Now, all three variables hold onto the same object, which first squares > all > > elements and than takes the first 1000. > > This is because the programmer did not understand what he did. No? > > > > Stef > > PS: I played with infinite stream and iteration back in 1993 in CLOS. > Now I do not like to mix things because it breaks my flow of thinking. > > > > > > Best, > > Steffen > > > > > > > > > > > > Am .06.2017, 21:28 Uhr, schrieb Damien Pollet > > <damien.pollet+pharo(a)gmail.com>: > > > >> If I recall correctly, there is an alternate protocol that looks more > like > >> xtreams or the traditional select/collect iterations. > >> > >> On 2 June 2017 at 21:12, Stephane Ducasse <stepharo.self(a)gmail.com> > wrote: > >> > >>> I have a design question > >>> > >>> why the library is implemented in functional style vs messages? > >>> I do not see why this is needed. To my eyes the compact notation > >>> goes against readibility of code and it feels ad-hoc in Smalltalk. > >>> > >>> > >>> I really prefer > >>> > >>> square := Map function: #squared. > >>> take := Take number: 1000. > >>> > >>> Because I know that I can read it and understand it. > >>> From that perspective I prefer Xtreams. > >>> > >>> Stef > >>> > >>> > >>> > >>> > >>> > >>> > >>> > >>> > >>> > >>> On Wed, May 31, 2017 at 2:23 PM, Steffen MÃ¤rcker <merkste(a)web.de> > wrote: > >>> > >>>> Hi, > >>>> > >>>> I am the developer of the library 'Transducers' for VisualWorks. It > was > >>>> formerly known as 'Reducers', but this name was a poor choice. I'd > like > >>>> to > >>>> port it to Pharo, if there is any interest on your side. I hope to > learn > >>>> more about Pharo in this process, since I am mainly a VW guy. And most > >>>> likely, I will come up with a bunch of questions. :-) > >>>> > >>>> Meanwhile, I'll cross-post the introduction from VWnc below. I'd be > very > >>>> happy to hear your optinions, questions and I hope we can start a > >>>> fruitful > >>>> discussion - even if there is not Pharo port yet. > >>>> > >>>> Best, Steffen > >>>> > >>>> > >>>> > >>>> Transducers are building blocks that encapsulate how to process > elements > >>>> of a data sequence independently of the underlying input and output > >>>> source. > >>>> > >>>> > >>>> > >>>> # Overview > >>>> > >>>> ## Encapsulate > >>>> Implementations of enumeration methods, such as #collect:, have the > >>>> logic > >>>> how to process a single element in common. > >>>> However, that logic is reimplemented each and every time. Transducers > >>>> make > >>>> it explicit and facilitate re-use and coherent behavior. > >>>> For example: > >>>> - #collect: requires mapping: (aBlock1 map) > >>>> - #select: requires filtering: (aBlock2 filter) > >>>> > >>>> > >>>> ## Compose > >>>> In practice, algorithms often require multiple processing steps, e.g., > >>>> mapping only a filtered set of elements. > >>>> Transducers are inherently composable, and hereby, allow to make the > >>>> combination of steps explicit. > >>>> Since transducers do not build intermediate collections, their > >>>> composition > >>>> is memory-efficient. > >>>> For example: > >>>> - (aBlock1 filter) * (aBlock2 map) "(1.) filter and (2.) map > elements" > >>>> > >>>> > >>>> ## Re-Use > >>>> Transducers are decoupled from the input and output sources, and > hence, > >>>> they can be reused in different contexts. > >>>> For example: > >>>> - enumeration of collections > >>>> - processing of streams > >>>> - communicating via channels > >>>> > >>>> > >>>> > >>>> # Usage by Example > >>>> > >>>> We build a coin flipping experiment and count the occurrence of heads > >>>> and > >>>> tails. > >>>> > >>>> First, we associate random numbers with the sides of a coin. > >>>> > >>>> scale := [:x | (x * 2 + 1) floor] map. > >>>> sides := #(heads tails) replace. > >>>> > >>>> Scale is a transducer that maps numbers x between 0 and 1 to 1 and 2. > >>>> Sides is a transducer that replaces the numbers with heads an tails by > >>>> lookup in an array. > >>>> Next, we choose a number of samples. > >>>> > >>>> count := 1000 take. > >>>> > >>>> Count is a transducer that takes 1000 elements from a source. > >>>> We keep track of the occurrences of heads an tails using a bag. > >>>> > >>>> collect := [:bag :c | bag add: c; yourself]. > >>>> > >>>> Collect is binary block (reducing function) that collects events in a > >>>> bag. > >>>> We assemble the experiment by transforming the block using the > >>>> transducers. > >>>> > >>>> experiment := (scale * sides * count) transform: collect. > >>>> > >>>> From left to right we see the steps involved: scale, sides, count > and > >>>> collect. > >>>> Transforming assembles these steps into a binary block (reducing > >>>> function) > >>>> we can use to run the experiment. > >>>> > >>>> samples := Random new > >>>> reduce: experiment > >>>> init: Bag new. > >>>> > >>>> Here, we use #reduce:init:, which is mostly similar to #inject:into:. > >>>> To execute a transformation and a reduction together, we can use > >>>> #transduce:reduce:init:. > >>>> > >>>> samples := Random new > >>>> transduce: scale * sides * count > >>>> reduce: collect > >>>> init: Bag new. > >>>> > >>>> We can also express the experiment as data-flow using #<~. > >>>> This enables us to build objects that can be re-used in other > >>>> experiments. > >>>> > >>>> coin := sides <~ scale <~ Random new. > >>>> flip := Bag <~ count. > >>>> > >>>> Coin is an eduction, i.e., it binds transducers to a source and > >>>> understands #reduce:init: among others. > >>>> Flip is a transformed reduction, i.e., it binds transducers to a > >>>> reducing > >>>> function and an initial value. > >>>> By sending #<~, we draw further samples from flipping the coin. > >>>> > >>>> samples := flip <~ coin. > >>>> > >>>> This yields a new Bag with another 1000 samples. > >>>> > >>>> > >>>> > >>>> # Basic Concepts > >>>> > >>>> ## Reducing Functions > >>>> > >>>> A reducing function represents a single step in processing a data > >>>> sequence. > >>>> It takes an accumulated result and a value, and returns a new > >>>> accumulated > >>>> result. > >>>> For example: > >>>> > >>>> collect := [:col :e | col add: e; yourself]. > >>>> sum := #+. > >>>> > >>>> A reducing function can also be ternary, i.e., it takes an accumulated > >>>> result, a key and a value. > >>>> For example: > >>>> > >>>> collect := [:dic :k :v | dict at: k put: v; yourself]. > >>>> > >>>> Reducing functions may be equipped with an optional completing action. > >>>> After finishing processing, it is invoked exactly once, e.g., to free > >>>> resources. > >>>> > >>>> stream := [:str :e | str nextPut: each; yourself] completing: > >>>> #close. > >>>> absSum := #+ completing: #abs > >>>> > >>>> A reducing function can end processing early by signaling Reduced > with a > >>>> result. > >>>> This mechanism also enables the treatment of infinite sources. > >>>> > >>>> nonNil := [:res :e | e ifNil: [Reduced signalWith: res] ifFalse: > >>>> [res]]. > >>>> > >>>> The primary approach to process a data sequence is the reducing > protocol > >>>> with the messages #reduce:init: and #transduce:reduce:init: if > >>>> transducers > >>>> are involved. > >>>> The behavior is similar to #inject:into: but in addition it takes care > >>>> of: > >>>> - handling binary and ternary reducing functions, > >>>> - invoking the completing action after finishing, and > >>>> - stopping the reduction if Reduced is signaled. > >>>> The message #transduce:reduce:init: just combines the transformation > and > >>>> the reducing step. > >>>> > >>>> However, as reducing functions are step-wise in nature, an application > >>>> may > >>>> choose other means to process its data. > >>>> > >>>> > >>>> ## Reducibles > >>>> > >>>> A data source is called reducible if it implements the reducing > >>>> protocol. > >>>> Default implementations are provided for collections and streams. > >>>> Additionally, blocks without an argument are reducible, too. > >>>> This allows to adapt to custom data sources without additional effort. > >>>> For example: > >>>> > >>>> "XStreams adaptor" > >>>> xstream := filename reading. > >>>> reducible := [[xstream get] on: Incomplete do: [Reduced signal]]. > >>>> > >>>> "natural numbers" > >>>> n := 0. > >>>> reducible := [n := n+1]. > >>>> > >>>> > >>>> ## Transducers > >>>> > >>>> A transducer is an object that transforms a reducing function into > >>>> another. > >>>> Transducers encapsulate common steps in processing data sequences, > such > >>>> as > >>>> map, filter, concatenate, and flatten. > >>>> A transducer transforms a reducing function into another via > #transform: > >>>> in order to add those steps. > >>>> They can be composed using #* which yields a new transducer that does > >>>> both > >>>> transformations. > >>>> Most transducers require an argument, typically blocks, symbols or > >>>> numbers: > >>>> > >>>> square := Map function: #squared. > >>>> take := Take number: 1000. > >>>> > >>>> To facilitate compact notation, the argument types implement > >>>> corresponding > >>>> methods: > >>>> > >>>> squareAndTake := #squared map * 1000 take. > >>>> > >>>> Transducers requiring no argument are singletons and can be accessed > by > >>>> their class name. > >>>> > >>>> flattenAndDedupe := Flatten * Dedupe. > >>>> > >>>> > >>>> > >>>> # Advanced Concepts > >>>> > >>>> ## Data flows > >>>> > >>>> Processing a sequence of data can often be regarded as a data flow. > >>>> The operator #<~ allows define a flow from a data source through > >>>> processing steps to a drain. > >>>> For example: > >>>> > >>>> squares := Set <~ 1000 take <~ #squared map <~ (1 to: 1000). > >>>> fileOut writeStream <~ #isSeparator filter <~ fileIn readStream. > >>>> > >>>> In both examples #<~ is only used to set up the data flow using > reducing > >>>> functions and transducers. > >>>> In contrast to streams, transducers are completely independent from > >>>> input > >>>> and output sources. > >>>> Hence, we have a clear separation of reading data, writing data and > >>>> processing elements. > >>>> - Sources know how to iterate over data with a reducing function, > e.g., > >>>> via #reduce:init:. > >>>> - Drains know how to collect data using a reducing function. > >>>> - Transducers know how to process single elements. > >>>> > >>>> > >>>> ## Reductions > >>>> > >>>> A reduction binds an initial value or a block yielding an initial > value > >>>> to > >>>> a reducing function. > >>>> The idea is to define a ready-to-use process that can be applied in > >>>> different contexts. > >>>> Reducibles handle reductions via #reduce: and #transduce:reduce: > >>>> For example: > >>>> > >>>> sum := #+ init: 0. > >>>> sum1 := #(1 1 1) reduce: sum. > >>>> sum2 := (1 to: 1000) transduce: #odd filter reduce: sum. > >>>> > >>>> asSet := [:set :e | set add: e; yourself] initializer: [Set new]. > >>>> set1 := #(1 1 1) reduce: asSet. > >>>> set2 := #(1 to: 1000) transduce: #odd filter reduce: asSet. > >>>> > >>>> By combining a transducer with a reduction, a process can be further > >>>> modified. > >>>> > >>>> sumOdds := sum <~ #odd filter > >>>> setOdds := asSet <~ #odd filter > >>>> > >>>> > >>>> ## Eductions > >>>> > >>>> An eduction combines a reducible data sources with a transducer. > >>>> The idea is to define a transformed (virtual) data source that needs > not > >>>> to be stored in memory. > >>>> > >>>> odds1 := #odd filter <~ #(1 2 3) readStream. > >>>> odds2 := #odd filter <~ (1 to 1000). > >>>> > >>>> Depending on the underlying source, eductions can be processed once > >>>> (streams, e.g., odds1) or multiple times (collections, e.g., odds2). > >>>> Since no intermediate data is stored, transducers actions are lazy, > >>>> i.e., > >>>> they are invoked each time the eduction is processed. > >>>> > >>>> > >>>> > >>>> # Origins > >>>> > >>>> Transducers is based on the same-named Clojure library and its ideas. > >>>> Please see: > >>>> http://clojure.org/transducers > >>>> > >>>> > > > > >

June 5, 2017

Re: [Pharo-users] Saving selected changes in Monticello

by Peter Uhnak

Komitter could indeed help you, see https://www.peteruhnak.com/blog/2016/08/12/fine-grained-committing-and-exte… Peter On Mon, Jun 05, 2017 at 08:27:23AM +0200, serge.stinckwich(a)gmail.com wrote: > Kommiter available in default image allows you do cherry pick quite easily. > > EnvoyÃ© de mon iPhone > > > Le 5 juin 2017 Ã 07:14, Ben Coman <btc(a)openinworld.com> a Ã©crit : > > > > > > > >> On Mon, Jun 5, 2017 at 10:12 AM, Andreas Sunardi <a.sunardi(a)gmail.com> wrote: > >> I have a half done changes in my image, but I need to distribute the other changes that are done. I thought I was going to do this all at once, but now I realize I should split this into 2 commit versions. > >> > >> Is there a way in Monticello to say save my changes, but not this and that changes? I can't seem to find it nor in books. How do people deal with this situation? > > > > AFAIK, Monticello cannot cherry pick. One work around is probably something like... > > 1. Save the mcz locally > > 2. Merge back into a fresh image selecting only the bits you want. > > 3. Save as a second mcz. > > One issue is that the second mcz will have the first mcz as an ancestor, so before 2 you might create a new changeset to file out after 2, and load that into a second new image. yuck! > > > > Another alternative might be to use Tools > ChangeSorter to move the code you want to exclude from the mcz to a changeset, file that out and then revert that code in the image. After save the package to a mcz, reload the changeset. > > > > cheers -ben

June 5, 2017

Re: [Pharo-users] snap morphs/windows to each other when dragging

by Stephane Ducasse

I do not know that by default. Especially since the drag and drop is when the mous is inside. this is anice scenario for bloc :) On Sun, Jun 4, 2017 at 2:51 PM, Peter Uhnak <i.uhnak(a)gmail.com> wrote: > Hi, > > is it possible to tell windows to "snap" to other windows when dragging? > > So e.g. when I am dragging Playground window, it will try to snap side by side with a close-by another window, so they don't overlap (unless I e.g. press shift or something). > > Thanks, > Peter >

June 5, 2017

Re: [Pharo-users] Porting Transducers to Pharo

by Stephane Ducasse

Hi Steffen > The short answer is that the compact notation turned out to work much better > for me in my code, especially, if multiple transducers are involved. But > that's my personal taste. You can choose which suits you better. In fact, > > 1000 take. > > just sits on top and simply calls > > Take number: 1000. To me this is much much better. > If the need arises, we could of course factor the compact notation out into > a separate package. Good idea Btw, would you prefer (Take n: 1000) over (Take number: > 1000)? I tend to prefer explicit selector :) > Damien, you're right, I experimented with additional styles. Right now, we > already have in the basic Transducer package: > > (collection transduce: #squared map * 1000 take. "which is equal to" > (collection transduce: #squared map) transduce: 1000 take. > > Basically, one can split #transduce:reduce:init: into single calls of > #transduce:, #reduce:, and #init:, depending on the needs. > I also have an (unfinished) extension, that allows to write: > > (collection transduce map: #squared) take: 1000. To me this is much mre readable. I cannot and do not want to use the other forms. > This feels familiar, but becomes a bit hard to read if more than two steps > are needed. > > collection transduce > map: #squared; > take: 1000. Why this is would hard to read. We do that all the time everywhere. > I think, this alternative would reads nicely. But as the message chain has > to modify the underlying object (an eduction), very snaky side effects may > occur. E.g., consider > > eduction := collection transduce. > squared := eduction map: #squared. > take := squared take: 1000. > > Now, all three variables hold onto the same object, which first squares all > elements and than takes the first 1000. This is because the programmer did not understand what he did. No? Stef PS: I played with infinite stream and iteration back in 1993 in CLOS. Now I do not like to mix things because it breaks my flow of thinking. > > Best, > Steffen > > > > > > Am .06.2017, 21:28 Uhr, schrieb Damien Pollet > <damien.pollet+pharo(a)gmail.com>: > >> If I recall correctly, there is an alternate protocol that looks more like >> xtreams or the traditional select/collect iterations. >> >> On 2 June 2017 at 21:12, Stephane Ducasse <stepharo.self(a)gmail.com> wrote: >> >>> I have a design question >>> >>> why the library is implemented in functional style vs messages? >>> I do not see why this is needed. To my eyes the compact notation >>> goes against readibility of code and it feels ad-hoc in Smalltalk. >>> >>> >>> I really prefer >>> >>> square := Map function: #squared. >>> take := Take number: 1000. >>> >>> Because I know that I can read it and understand it. >>> From that perspective I prefer Xtreams. >>> >>> Stef >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> On Wed, May 31, 2017 at 2:23 PM, Steffen MÃ¤rcker <merkste(a)web.de> wrote: >>> >>>> Hi, >>>> >>>> I am the developer of the library 'Transducers' for VisualWorks. It was >>>> formerly known as 'Reducers', but this name was a poor choice. I'd like >>>> to >>>> port it to Pharo, if there is any interest on your side. I hope to learn >>>> more about Pharo in this process, since I am mainly a VW guy. And most >>>> likely, I will come up with a bunch of questions. :-) >>>> >>>> Meanwhile, I'll cross-post the introduction from VWnc below. I'd be very >>>> happy to hear your optinions, questions and I hope we can start a >>>> fruitful >>>> discussion - even if there is not Pharo port yet. >>>> >>>> Best, Steffen >>>> >>>> >>>> >>>> Transducers are building blocks that encapsulate how to process elements >>>> of a data sequence independently of the underlying input and output >>>> source. >>>> >>>> >>>> >>>> # Overview >>>> >>>> ## Encapsulate >>>> Implementations of enumeration methods, such as #collect:, have the >>>> logic >>>> how to process a single element in common. >>>> However, that logic is reimplemented each and every time. Transducers >>>> make >>>> it explicit and facilitate re-use and coherent behavior. >>>> For example: >>>> - #collect: requires mapping: (aBlock1 map) >>>> - #select: requires filtering: (aBlock2 filter) >>>> >>>> >>>> ## Compose >>>> In practice, algorithms often require multiple processing steps, e.g., >>>> mapping only a filtered set of elements. >>>> Transducers are inherently composable, and hereby, allow to make the >>>> combination of steps explicit. >>>> Since transducers do not build intermediate collections, their >>>> composition >>>> is memory-efficient. >>>> For example: >>>> - (aBlock1 filter) * (aBlock2 map) "(1.) filter and (2.) map elements" >>>> >>>> >>>> ## Re-Use >>>> Transducers are decoupled from the input and output sources, and hence, >>>> they can be reused in different contexts. >>>> For example: >>>> - enumeration of collections >>>> - processing of streams >>>> - communicating via channels >>>> >>>> >>>> >>>> # Usage by Example >>>> >>>> We build a coin flipping experiment and count the occurrence of heads >>>> and >>>> tails. >>>> >>>> First, we associate random numbers with the sides of a coin. >>>> >>>> scale := [:x | (x * 2 + 1) floor] map. >>>> sides := #(heads tails) replace. >>>> >>>> Scale is a transducer that maps numbers x between 0 and 1 to 1 and 2. >>>> Sides is a transducer that replaces the numbers with heads an tails by >>>> lookup in an array. >>>> Next, we choose a number of samples. >>>> >>>> count := 1000 take. >>>> >>>> Count is a transducer that takes 1000 elements from a source. >>>> We keep track of the occurrences of heads an tails using a bag. >>>> >>>> collect := [:bag :c | bag add: c; yourself]. >>>> >>>> Collect is binary block (reducing function) that collects events in a >>>> bag. >>>> We assemble the experiment by transforming the block using the >>>> transducers. >>>> >>>> experiment := (scale * sides * count) transform: collect. >>>> >>>> From left to right we see the steps involved: scale, sides, count and >>>> collect. >>>> Transforming assembles these steps into a binary block (reducing >>>> function) >>>> we can use to run the experiment. >>>> >>>> samples := Random new >>>> reduce: experiment >>>> init: Bag new. >>>> >>>> Here, we use #reduce:init:, which is mostly similar to #inject:into:. >>>> To execute a transformation and a reduction together, we can use >>>> #transduce:reduce:init:. >>>> >>>> samples := Random new >>>> transduce: scale * sides * count >>>> reduce: collect >>>> init: Bag new. >>>> >>>> We can also express the experiment as data-flow using #<~. >>>> This enables us to build objects that can be re-used in other >>>> experiments. >>>> >>>> coin := sides <~ scale <~ Random new. >>>> flip := Bag <~ count. >>>> >>>> Coin is an eduction, i.e., it binds transducers to a source and >>>> understands #reduce:init: among others. >>>> Flip is a transformed reduction, i.e., it binds transducers to a >>>> reducing >>>> function and an initial value. >>>> By sending #<~, we draw further samples from flipping the coin. >>>> >>>> samples := flip <~ coin. >>>> >>>> This yields a new Bag with another 1000 samples. >>>> >>>> >>>> >>>> # Basic Concepts >>>> >>>> ## Reducing Functions >>>> >>>> A reducing function represents a single step in processing a data >>>> sequence. >>>> It takes an accumulated result and a value, and returns a new >>>> accumulated >>>> result. >>>> For example: >>>> >>>> collect := [:col :e | col add: e; yourself]. >>>> sum := #+. >>>> >>>> A reducing function can also be ternary, i.e., it takes an accumulated >>>> result, a key and a value. >>>> For example: >>>> >>>> collect := [:dic :k :v | dict at: k put: v; yourself]. >>>> >>>> Reducing functions may be equipped with an optional completing action. >>>> After finishing processing, it is invoked exactly once, e.g., to free >>>> resources. >>>> >>>> stream := [:str :e | str nextPut: each; yourself] completing: >>>> #close. >>>> absSum := #+ completing: #abs >>>> >>>> A reducing function can end processing early by signaling Reduced with a >>>> result. >>>> This mechanism also enables the treatment of infinite sources. >>>> >>>> nonNil := [:res :e | e ifNil: [Reduced signalWith: res] ifFalse: >>>> [res]]. >>>> >>>> The primary approach to process a data sequence is the reducing protocol >>>> with the messages #reduce:init: and #transduce:reduce:init: if >>>> transducers >>>> are involved. >>>> The behavior is similar to #inject:into: but in addition it takes care >>>> of: >>>> - handling binary and ternary reducing functions, >>>> - invoking the completing action after finishing, and >>>> - stopping the reduction if Reduced is signaled. >>>> The message #transduce:reduce:init: just combines the transformation and >>>> the reducing step. >>>> >>>> However, as reducing functions are step-wise in nature, an application >>>> may >>>> choose other means to process its data. >>>> >>>> >>>> ## Reducibles >>>> >>>> A data source is called reducible if it implements the reducing >>>> protocol. >>>> Default implementations are provided for collections and streams. >>>> Additionally, blocks without an argument are reducible, too. >>>> This allows to adapt to custom data sources without additional effort. >>>> For example: >>>> >>>> "XStreams adaptor" >>>> xstream := filename reading. >>>> reducible := [[xstream get] on: Incomplete do: [Reduced signal]]. >>>> >>>> "natural numbers" >>>> n := 0. >>>> reducible := [n := n+1]. >>>> >>>> >>>> ## Transducers >>>> >>>> A transducer is an object that transforms a reducing function into >>>> another. >>>> Transducers encapsulate common steps in processing data sequences, such >>>> as >>>> map, filter, concatenate, and flatten. >>>> A transducer transforms a reducing function into another via #transform: >>>> in order to add those steps. >>>> They can be composed using #* which yields a new transducer that does >>>> both >>>> transformations. >>>> Most transducers require an argument, typically blocks, symbols or >>>> numbers: >>>> >>>> square := Map function: #squared. >>>> take := Take number: 1000. >>>> >>>> To facilitate compact notation, the argument types implement >>>> corresponding >>>> methods: >>>> >>>> squareAndTake := #squared map * 1000 take. >>>> >>>> Transducers requiring no argument are singletons and can be accessed by >>>> their class name. >>>> >>>> flattenAndDedupe := Flatten * Dedupe. >>>> >>>> >>>> >>>> # Advanced Concepts >>>> >>>> ## Data flows >>>> >>>> Processing a sequence of data can often be regarded as a data flow. >>>> The operator #<~ allows define a flow from a data source through >>>> processing steps to a drain. >>>> For example: >>>> >>>> squares := Set <~ 1000 take <~ #squared map <~ (1 to: 1000). >>>> fileOut writeStream <~ #isSeparator filter <~ fileIn readStream. >>>> >>>> In both examples #<~ is only used to set up the data flow using reducing >>>> functions and transducers. >>>> In contrast to streams, transducers are completely independent from >>>> input >>>> and output sources. >>>> Hence, we have a clear separation of reading data, writing data and >>>> processing elements. >>>> - Sources know how to iterate over data with a reducing function, e.g., >>>> via #reduce:init:. >>>> - Drains know how to collect data using a reducing function. >>>> - Transducers know how to process single elements. >>>> >>>> >>>> ## Reductions >>>> >>>> A reduction binds an initial value or a block yielding an initial value >>>> to >>>> a reducing function. >>>> The idea is to define a ready-to-use process that can be applied in >>>> different contexts. >>>> Reducibles handle reductions via #reduce: and #transduce:reduce: >>>> For example: >>>> >>>> sum := #+ init: 0. >>>> sum1 := #(1 1 1) reduce: sum. >>>> sum2 := (1 to: 1000) transduce: #odd filter reduce: sum. >>>> >>>> asSet := [:set :e | set add: e; yourself] initializer: [Set new]. >>>> set1 := #(1 1 1) reduce: asSet. >>>> set2 := #(1 to: 1000) transduce: #odd filter reduce: asSet. >>>> >>>> By combining a transducer with a reduction, a process can be further >>>> modified. >>>> >>>> sumOdds := sum <~ #odd filter >>>> setOdds := asSet <~ #odd filter >>>> >>>> >>>> ## Eductions >>>> >>>> An eduction combines a reducible data sources with a transducer. >>>> The idea is to define a transformed (virtual) data source that needs not >>>> to be stored in memory. >>>> >>>> odds1 := #odd filter <~ #(1 2 3) readStream. >>>> odds2 := #odd filter <~ (1 to 1000). >>>> >>>> Depending on the underlying source, eductions can be processed once >>>> (streams, e.g., odds1) or multiple times (collections, e.g., odds2). >>>> Since no intermediate data is stored, transducers actions are lazy, >>>> i.e., >>>> they are invoked each time the eduction is processed. >>>> >>>> >>>> >>>> # Origins >>>> >>>> Transducers is based on the same-named Clojure library and its ideas. >>>> Please see: >>>> http://clojure.org/transducers >>>> >>>> >

June 5, 2017

Re: [Pharo-users] Porting Transducers to Pharo

by Stephane Ducasse

About NG this is strange but may be we were working on an old VW version. - I can help producing a nice document :) >> > > Do you mean like the booklets published over the last weeks? This would be > great. > yes now I do not want to help promoting a syntax that alienates me (and others because other people reported the saem to me). :) Do you have an idea, how to add a package comment to the simple file-out it > used? I think, a simple message send should suffice. > produce a monticello package, select the package and comment. >>>

June 5, 2017

Re: [Pharo-users] Porting Transducers to Pharo

by Stephane Ducasse

We do not work with fileouts :) You should produce packages with also a configuration and published them on smalltalkhub or git and in the MetaRepository. You can also add package comments On Sat, Jun 3, 2017 at 10:29 PM, Steffen MÃ¤rcker <merkste(a)web.de> wrote: > Dear all, > > attached are updated file-outs. I fixed a couple of annoyances that > slipped through yesterday evening. Most notable: > > 1) Random generator now works. > 2) Early termination via Reduced exception does MNU anymore. > 3) Printing a transducer holding a block does not MNU anymore. > > Please, give it a spin and tell me your impressions. (At least) The > coin-flipping the example from the package comment works now: > > scale := [:x | (x * 2 + 1) floor] map. > sides := #(heads tails) replace. > count := 1000 take. > collect := [:bag :c | bag add: c; yourself]. > experiment := (scale * sides * count) transform: collect. > "experiment cannot be re-used" > samples := Random new > reduce: experiment > init: Bag new. > "transform and reduce in one step" > samples := Random new > transduce: scale * sides * count > reduce: collect > init: Bag new. > "assemble coin (eduction) and flip (reduction) objects" > coin := sides <~ scale <~ Random new. > flip := Bag <~ count. > "flip coin =)" > samples := flip <~ coin. > > Cheers! > Steffen > > > > Am .06.2017, 23:08 Uhr, schrieb Steffen MÃ¤rcker <merkste(a)web.de>: > > Thanks, this appears to work. Attached you'll find the file-out from >> VisualWorks and the file-out from Pharo (includes package comment). >> >> Cheers! >> Steffen >> >> >> Am .06.2017, 20:06 Uhr, schrieb Yanni Chiu <yanni.code(a)gmail.com>: >> >> To get the extension methods into the Transducers package, the following >>> worked for me - edit the category to have the prefix '*Transducers-' >>> >>> 2710c2710 >>> >>> < !Number methodsFor: 'transforming' stamp: ' 2/6/17 15:38'! >>> >>> --- >>> >>> !Number methodsFor: '*Transducers-transforming' stamp: ' 2/6/17 15:38'! >>>> >>> >>> >>> On Fri, Jun 2, 2017 at 11:05 AM, Steffen MÃ¤rcker <merkste(a)web.de> wrote: >>> >>> Dear all, >>>> >>>> thanks for the many suggestions. I didn't had time to test all >>>> import/export ways yet. But for now, I can report on two: >>>> >>>> 1) NGFileOuter >>>> Unfortunately It raised several MNUs in my image. I'll investigate them >>>> later. >>>> >>>> 2) FileOut30 (VW Contributed) >>>> I was able to file out the code except for the package definition. >>>> Replacing {category: ''} in the class definitions with {package: >>>> 'Transducers'} fixed that. However, methods that extend existing classes >>>> did not end up in the Transducers package. Is there a similar easy >>>> change >>>> to the file-out making that happen? Also I'd like to add the package >>>> comment if that's possible. >>>> >>>> Most things appear to work as far as I can see. Two exceptions: >>>> 1) Random is a subclass of Stream in VW and in Pharo it is not. Hence, >>>> I'll have to copy some methods from Stream to Random. >>>> 2) I used #beImmutable in VW but I couldn't yet figure out how to make >>>> objects immutable in Pharo. >>>> >>>> However, until the tests are ported, I cannot guarantee. Porting the >>>> test >>>> suite will be another beast, since I rely on the excellent >>>> mocking/stubbing >>>> library DoubleAgents by Randy Coulman. I am not sure how I will handle >>>> that. In general, I think it would be really worth the effort to be >>>> ported >>>> to Pharo, too. DoubleAgents is pretty powerful and produces easy to read >>>> and understand mocking/stubbing code. Personally, I prefer it clearly, >>>> e.g., over Mocketry (no offence intended!). >>>> >>>> Attached you'll find the file-out that I loaded into Pharo. The issues >>>> above are not addressed yet. However, the following example works: >>>> >>>> | scale sides count collect experiment random samples coin flip | >>>> scale := [:x | (x * 2 + 1) floor] map. >>>> sides := #(heads tails) replace. >>>> count := 1000 take. >>>> collect := [:bag :c | bag add: c; yourself]. >>>> experiment := (scale * sides * count) transform: collect. >>>> random := #(0.1 0.3 0.4 0.5 0.6 0.7 0.8 0.9). >>>> >>>> samples := random >>>> reduce: experiment >>>> init: Bag new. >>>> >>>> samples := random >>>> transduce: scale * sides * count >>>> reduce: collect >>>> init: Bag new. >>>> >>>> coin := sides <~ scale <~ random. >>>> flip := Bag <~ count. >>>> >>>> samples := flip <~ coin. >>>> >>>> >>>> Best, Steffen >>>> >>>> >>>> >>>> Am .06.2017, 08:16 Uhr, schrieb Stephane Ducasse >>>> <stepharo.self(a)gmail.com >>>> >: >>>> >>>> There is a package for that NGFileOuter or something like that on cincom >>>> >>>>> store. >>>>> We used it for mobydic code. >>>>> >>>>> On Wed, May 31, 2017 at 6:35 PM, Alexandre Bergel < >>>>> alexandre.bergel(a)me.com> >>>>> wrote: >>>>> >>>>> If I remember correctly, there is a parcel in VisualWorks to export a >>>>> file >>>>> >>>>>> out (Squeak format). >>>>>> >>>>>> @Milton, can you give a hand to Steffen? >>>>>> >>>>>> Alexandre >>>>>> -- >>>>>> _,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;: >>>>>> Alexandre Bergel http://www.bergel.eu >>>>>> ^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;. >>>>>> >>>>>> >>>>>> >>>>>> On May 31, 2017, at 10:32 AM, Steffen MÃ¤rcker <merkste(a)web.de> wrote: >>>>>> >>>>>> Thanks for the encouraging response! First question: Which is the >>>>>> recommended (friction free) way to exchange code between VW and Pharo? >>>>>> >>>>>> Cheers! >>>>>> Steffen >>>>>> >>>>>> Am .05.2017, 16:22 Uhr, schrieb Alexandre Bergel < >>>>>> alexandre.bergel(a)me.com >>>>>> >: >>>>>> >>>>>> I second Sven. This is very exciting! >>>>>> >>>>>> Let us know when you have something ready to be tested. >>>>>> >>>>>> Alexandre >>>>>> >>>>>>

June 5, 2017

Re: [Pharo-users] STON Question

by Stephane Ducasse

Sven I know what Ston is :) Now Pillar dev used Ston as input and it works. Then with some hooks they let the user convert the strings into specific objects and this is ok. Now I want to add export in Ston and for configurations I need to control for the application and not as a ston object the value saved. For example a file reference should not be just a file reference in Ston but a string relative the the baseDirectory of the configuration. So I thought that I can build a hook and control the call to Ston (convert the object before to the correct values) and export. It should be working now doing this I found myself redoing the output of Ston. So I will do it. Then I thought that may be I could reuse this logic. Stef On Sun, Jun 4, 2017 at 11:49 PM, Sven Van Caekenberghe <sven(a)stfx.eu> wrote: > Stef, > > STON is like FUEL, it can write any object to a stream and read it back. > Although you can customise how this is done, only one way of doing so is > supported (i.e. you cannot change the format for each application). > > People have used STON for various applications now, including for > configuration stuff (because it is a textual format that is easy to read). > > I would suggest you just try to see what your config looks like once you > have the objects in Pharo. > > STON toStringPretty: myConfig. > > Then we can see how to tune the representation. > > Sven > > > On 4 Jun 2017, at 22:58, Stephane Ducasse <stepharo.self(a)gmail.com> > wrote: > > > > Hi sven > > > > I'm working on a new configuration frameworks similar to the one use > pillar.conf. > > > > So basically I have > > > > ston := '{ > > "newLine":#unix, > > "separateOutputFiles":true > > }'. > > and I want to recreate it. > > > > So I did > > > > Object >> toConfigurationString > > > > ^ STON toString: self > > > > SimpleConfiguration >> exportStream > > > > ^ String streamContents: [ :str | > > str << '{' . > > self propertiesKeysAndValuesDo: [ :key :value| > > str << key toConfigurationString. > > str << ':'. > > str << value toConfigurationString. > > str << ','. > > str lf. > > ]. > > str << '}'. > > str contents > > ] > > > > The idea is that for special configuration values people should be able > to define > > how to go from the object to configuration. > > For example for some FileReference I want to have just the path up to > the baseDirectory. > > > > Now I wonder if I could not better reuse ston. > > I saw the stonOn: > > but I did not look further because I was wondering how the writer where > passed. > > > > Any feedback is welcome. > > > > Stef (now bed time). > > > > >

June 5, 2017

Re: [Pharo-users] Saving selected changes in Monticello

by serge.stinckwich＠gmail.com

Kommiter available in default image allows you do cherry pick quite easily. EnvoyÃ© de mon iPhone > Le 5 juin 2017 Ã 07:14, Ben Coman <btc(a)openinworld.com> a Ã©crit : > > > >> On Mon, Jun 5, 2017 at 10:12 AM, Andreas Sunardi <a.sunardi(a)gmail.com> wrote: >> I have a half done changes in my image, but I need to distribute the other changes that are done. I thought I was going to do this all at once, but now I realize I should split this into 2 commit versions. >> >> Is there a way in Monticello to say save my changes, but not this and that changes? I can't seem to find it nor in books. How do people deal with this situation? > > AFAIK, Monticello cannot cherry pick. One work around is probably something like... > 1. Save the mcz locally > 2. Merge back into a fresh image selecting only the bits you want. > 3. Save as a second mcz. > One issue is that the second mcz will have the first mcz as an ancestor, so before 2 you might create a new changeset to file out after 2, and load that into a second new image. yuck! > > Another alternative might be to use Tools > ChangeSorter to move the code you want to exclude from the mcz to a changeset, file that out and then revert that code in the image. After save the package to a mcz, reload the changeset. > > cheers -ben

June 5, 2017

Re: [Pharo-users] Saving selected changes in Monticello

by Ben Coman

On Mon, Jun 5, 2017 at 10:12 AM, Andreas Sunardi <a.sunardi(a)gmail.com> wrote: > I have a half done changes in my image, but I need to distribute the other > changes that are done. I thought I was going to do this all at once, but > now I realize I should split this into 2 commit versions. > > Is there a way in Monticello to say save my changes, but not this and that > changes? I can't seem to find it nor in books. How do people deal with this > situation? > AFAIK, Monticello cannot cherry pick. One work around is probably something like... 1. Save the mcz locally 2. Merge back into a fresh image selecting only the bits you want. 3. Save as a second mcz. One issue is that the second mcz will have the first mcz as an ancestor, so before 2 you might create a new changeset to file out after 2, and load that into a second new image. yuck! Another alternative might be to use Tools > ChangeSorter to move the code you want to exclude from the mcz to a changeset, file that out and then revert that code in the image. After save the package to a mcz, reload the changeset. cheers -ben

June 5, 2017

Re: [Pharo-users] Wiring objects, IoC and Service Locator

by Ben Coman

Sorry I'm not familiar with the pattern, so I don't have a direct answer, and the following might not have a direct answer either, but in general I'd strongly suggest two books for adapting from static OO languages. 1. The Design Patterns Smalltalk Companion, Alpert, Brown & Woolf - including some discussion on why certain patterns required for static-OO are redundant in Smalltalk. My naive guess is the Factory, Strategy and/or Template patterns may apply. 2. A Mentoring Course on Smalltalk, Valloud On Mon, Jun 5, 2017 at 5:17 AM, Vitor Medina Cruz <vitormcruz(a)gmail.com> wrote: > Hello, > > I would like to know how people in Pharo ecosystem do to deal with object > wiring, as described by Marting Fowler in https://martinfowler.com/ > articles/injection.html#FormsOfDependencyInjection: > > "A common issue to deal with is how to wire together different elements: > how do you fit together this web controller architecture with that database > interface backing when they were built by different teams with little > knowledge of each other." > > He gives an example, I will leave it in java as it is simple enough to > understand: > > "class MovieLister... > > public Movie[] moviesDirectedBy(String arg) { > List allMovies = finder.findAll(); > for (Iterator it = allMovies.iterator(); it.hasNext();) { > Movie movie = (Movie) it.next(); > if (!movie.getDirector().equals(arg)) it.remove(); > } > return (Movie[]) allMovies.toArray(new Movie[allMovies.size()]); > > }" > > The question is how to provide the finder object in a decoupled matter, a > naive approach would be: > > " private MovieFinder finder; > > public MovieLister() { > finder = new ColonDelimitedMovieFinder("movies1.txt"); > > }" > I'm not really familiar with IoC or DI patterns, so just taking your example at face value, in Pharo I'd do... MovieLister>>moviesDirectedBy: director allMovies := finder allMovies. ^ allMovies select: [ :movie | movie getDirector = director ]. "although typically #getDirector would be renamed #director" MovieLister>>finder: movieFinder finder := movieFinder. to be used like this... lister := MovieLister new finder: (ColonDelimitedMovieFinder on: 'movies1.txt'). movies := lister moviesDirectedBy: 'Tarantino'. > > Which couples the MovieLister to the specific ColonDelimitedMovieFinder > class. > > Fowler explains how to decouple using an IoC framework or a Service > Locator. In Java and .Net IoC is used most of the time. I Googled how this > problem is approached in Smalltalk/Pharo, and I generally I found answers > "that is easy to do in Smalltalk, so there is no need of a framework", what > I miss is a description on *how* to do that: > Just to satisfy my curiosity, I did find... "MVC was invented on Smalltalk and is arguably the original Inversion of Control framework. ... I think that IOC or the Dependency Injection pattern solves a problem that doesn't really exist in the Smalltalk environment. Smalltalk is an untyped dynamic language and uses message passing to communicate. This makes for objects that are loosely coupled by nature at the language level" http://www.weizhishi.tech/questions/296612/smalltalk-and-ioc And this... "In an explicitly-typed language like C++, C#, or Java, it is necessary to define an explicit interface for the injected collaborator. The real collaborator and the substitute both have to implement the interface. In a dynamically-typed language like Ruby [& Smalltalk], explicit interfaces are not necessary. We can just take advantage of 'duck-typing'." http://randycoulman.com/blog/2013/06/04/affordances-dependency-injection/ And GIlad Bracha knows a bit about Java... "I think that if youâre stuck with a mainstream language, [dependency Injection] may be a reasonable work around. It requires a significant degree of preplanning, and makes your application dependent on one more piece of machinery that has nothing to do with the actual problem the application is trying to solve. On the positive side, it helps guarantee employment for software engineers. That said, itâs important to understand that DIFs are just a work around for a deficiency in the underlying language. So why not get rid of constructors and have a class declaration create a factory object instead? Well, Smalltalk did just that a generation ago. Every time you define a class, you define the factory object for its instances." https://gbracha.blogspot.com.au/2007/06/constructors-considered-harmful.html btw, following Randy's example the two steps #new & #finder: should hidden/combined by renaming MovieLister>>finder: to MovieLister>>initializeWithFinder: and adding... MovieLister class >> newWithFinder: finder ^ self basicNew initializeWithFinder: finder to be used like this... lister := MovieLister newWithFinder: (ColonDelimitedMovieFinder on: 'movies1.txt'). movies := lister moviesDirectedBy: 'Tarantino'. btw, while you are at it, if you haven't done this before, try implementing this using Smalltalk's version of TDD... https://www.youtube.com/watch?v=ymITEeAOtEA https://www.youtube.com/watch?v=XxqZVAOomfM In a clean image, first implement the following method and run the test, then fill code as needed just-in-time... MovieListerTest>>testColonDelimitedFinder lister := MovieLister newWithFinder: (ColonDelimitedMovieFinder on: 'movies1.txt'). movies := lister moviesDirectedBy: 'Tarantino'. self assert: (movies includes: 'Pulp Fiction') > https://stackoverflow.com/questions/243905/smalltalk-and-ioc > https://stackoverflow.com/questions/2684326/is-there-a- > dependency-injection-framework-for-smalltalk > https://stackoverflow.com/questions/243905/smalltalk-and-ioc/347477#347477 > I see similar comments to my references in these. I hope the bits I've focussed on are not redundant . > I know that in Smalltalk I can make MovieLister to receive, upon > construction, a class representing MovieFinder and call it construction > message. As long an object that responds to this message is provided, I can > create as many derivations I want and the MovieLister will be decoupled > from the MovieFinder. > Reading this, I think maybe all I've done with my example is echo this. So what I'm not clear on is what you mean by "wire things by hand" > That way, however, I still have to wire things by hand, and I am not sure > if this is what I am supposed to do in order to solve the decouple problem. > I would say use Pharo's TDD approach of coding-from-within-the-debugger. The beauty of it is not that you get a lot of test coverage. There other significant benefits are: A. Your API ends up designed "in the most natural way to be used" since each time you code how you want to use your API before you define the implementation. B. You only need to code the minimum to get that API aspect working. So you get a faster feedback loop on your design. C. You consistency API implementation, you might define a test like... MovieListerTest>>testAllFinders AbstractMovieFinder allSubclasses do: [ :finderclass | lister := MovieLister newWithFinder: (finderclass on: 'movies1.txt'). movies := lister moviesDirectedBy: 'Tarantino'. self assert: (movies includes: 'Pulp Fiction'). ] and then each time you add an AbstractMovieFinder subclass, you implementation is again just work through fixing the tests from within the debugger. > Can you explain me how this is done in Pharo? It's is usually wiring by > hand? Is there a simple construction that deals with the wiring problem > that I cannot foresee? > TDD helps you avoid worrying about problems that might not exist. cheers -ben > > Thanks in advance, > Vitor > > > >

June 5, 2017

Saving selected changes in Monticello

by Andreas Sunardi

I have a half done changes in my image, but I need to distribute the other changes that are done. I thought I was going to do this all at once, but now I realize I should split this into 2 commit versions. Is there a way in Monticello to say save my changes, but not this and that changes? I can't seem to find it nor in books. How do people deal with this situation? -- Andreas Sunardi

June 5, 2017

Re: [Pharo-users] Creating a BaselineOf from a ConfigurationOf>>#baselineXyz:

by HernÃ¡n Morales Durand

Hi Sean, I didn't tried too much but you may first have to match the node in the parse tree. Something like this: | node | node := (RBParseTreeRewriter treeMatching: '`@expr blessing: `#lit' in: (YourClass >> #baseline01:) parseTree). (node parent removeNode: node) newSource. Cheers, HernÃ¡n 2017-06-04 0:48 GMT-03:00 Sean P. DeNigris <sean(a)clipperadams.com>: > I'm trying to write a rewrite rule, but can't quite get it. > > I first want to remove `spec blessing: #baseline.` > > I tried the following with no effect: > > RBParseTreeRewriter new > replace: '`@expr blessing: `#lit' > with: ''; > executeTree: methodTree; > tree. > > NB: If I try to edit the expression instead of remove, by passing something > like '`@expr assert: `#lit' for #with:, it works > > What am I missing here? > > Thanks! > > > > ----- > Cheers, > Sean > -- > View this message in context: http://forum.world.st/ > Creating-a-BaselineOf-from-a-ConfigurationOf-baselineXyz-tp4949192.html > Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com. > >

June 5, 2017

Re: [Pharo-users] STON Question

by Sven Van Caekenberghe

Stef, STON is like FUEL, it can write any object to a stream and read it back. Although you can customise how this is done, only one way of doing so is supported (i.e. you cannot change the format for each application). People have used STON for various applications now, including for configuration stuff (because it is a textual format that is easy to read). I would suggest you just try to see what your config looks like once you have the objects in Pharo. STON toStringPretty: myConfig. Then we can see how to tune the representation. Sven > On 4 Jun 2017, at 22:58, Stephane Ducasse <stepharo.self(a)gmail.com> wrote: > > Hi sven > > I'm working on a new configuration frameworks similar to the one use pillar.conf. > > So basically I have > > ston := '{ > "newLine":#unix, > "separateOutputFiles":true > }'. > and I want to recreate it. > > So I did > > Object >> toConfigurationString > > ^ STON toString: self > > SimpleConfiguration >> exportStream > > ^ String streamContents: [ :str | > str << '{' . > self propertiesKeysAndValuesDo: [ :key :value| > str << key toConfigurationString. > str << ':'. > str << value toConfigurationString. > str << ','. > str lf. > ]. > str << '}'. > str contents > ] > > The idea is that for special configuration values people should be able to define > how to go from the object to configuration. > For example for some FileReference I want to have just the path up to the baseDirectory. > > Now I wonder if I could not better reuse ston. > I saw the stonOn: > but I did not look further because I was wondering how the writer where passed. > > Any feedback is welcome. > > Stef (now bed time). >

June 4, 2017

Wiring objects, IoC and Service Locator

by Vitor Medina Cruz

Hello, I would like to know how people in Pharo ecosystem do to deal with object wiring, as described by Marting Fowler in https://martinfowler.com/articles/injection.html#FormsOfDependencyInjection: "A common issue to deal with is how to wire together different elements: how do you fit together this web controller architecture with that database interface backing when they were built by different teams with little knowledge of each other." He gives an example, I will leave it in java as it is simple enough to understand: "class MovieLister... public Movie[] moviesDirectedBy(String arg) { List allMovies = finder.findAll(); for (Iterator it = allMovies.iterator(); it.hasNext();) { Movie movie = (Movie) it.next(); if (!movie.getDirector().equals(arg)) it.remove(); } return (Movie[]) allMovies.toArray(new Movie[allMovies.size()]); }" The question is how to provide the finder object in a decoupled matter, a naive approach would be: " private MovieFinder finder; public MovieLister() { finder = new ColonDelimitedMovieFinder("movies1.txt"); }" Which couples the MovieLister to the specific ColonDelimitedMovieFinder class. Fowler explains how to decouple using an IoC framework or a Service Locator. In Java and .Net IoC is used most of the time. I Googled how this problem is approached in Smalltalk/Pharo, and I generally I found answers "that is easy to do in Smalltalk, so there is no need of a framework", what I miss is a description on *how* to do that: https://stackoverflow.com/questions/243905/smalltalk-and-ioc https://stackoverflow.com/questions/2684326/is-there-a-dependency-injection… https://stackoverflow.com/questions/243905/smalltalk-and-ioc/347477#347477 I know that in Smalltalk I can make MovieLister to receive, upon construction, a class representing MovieFinder and call it construction message. As long an object that responds to this message is provided, I can create as many derivations I want and the MovieLister will be decoupled from the MovieFinder. That way, however, I still have to wire things by hand, and I am not sure if this is what I am supposed to do in order to solve the decouple problem. Can you explain me how this is done in Pharo? It's is usually wiring by hand? Is there a simple construction that deals with the wiring problem that I cannot foresee? Thanks in advance, Vitor

June 4, 2017

STON Question

by Stephane Ducasse

Hi sven I'm working on a new configuration frameworks similar to the one use pillar.conf. So basically I have ston := '{ "newLine":#unix, "separateOutputFiles":true }'. and I want to recreate it. So I did Object >> toConfigurationString ^ STON toString: self SimpleConfiguration >> exportStream ^ String streamContents: [ :str | str << '{' . self propertiesKeysAndValuesDo: [ :key :value| str << key toConfigurationString. str << ':'. str << value toConfigurationString. str << ','. str lf. ]. str << '}'. str contents ] The idea is that for special configuration values people should be able to define how to go from the object to configuration. For example for some FileReference I want to have just the path up to the baseDirectory. Now I wonder if I could not better reuse ston. I saw the stonOn: but I did not look further because I was wondering how the writer where passed. Any feedback is welcome. Stef (now bed time).

June 4, 2017

Deadline Extension - SLE 2017 (10th ACM SIGPLAN International Conference on Software Language Engineering)

by Andrei Chis

======================================================================== **Call for Papers** - **Deadline Extension** **Abstract Submission**: Friday 9, June 2017 **Paper Submission**: Friday 16, June 2017 ======================================================================== 10th ACM SIGPLAN International Conference on Software Language Engineering (SLE 2017) 23-24 October 2017, Vancouver, Canada (Co-located with SPLASH 2017) General chair: Benoit Combemale, University of Rennes 1, France Program co-chairs: Marjan Mernik, University of Maribor, Slovenia Bernhard Rumpe, RWTH Aachen University, Germany Artifact evaluation chairs: Tanja Mayerhofer, TU Wien, Austria Laurence Tratt, King's College London, UK Keynote Speaker: Peter D. Mosses, Swansea University, UK (http://cs.swan.ac.uk/~cspdm/) http://conf.researchr.org/track/sle-2017/sle-2017-papers http://www.sleconf.org/2017 Follow us on twitter: https://twitter.com/sleconf ======================================================================== Software Language Engineering (SLE) is the application of systematic, disciplined, and measurable approaches to the development, use, deployment, and maintenance of software languages. The term "software language" is used broadly, and includes: general-purpose programming languages; domain-specific languages (e.g. BPMN, Simulink, Modelica); modeling and metamodeling languages (e.g. SysML and UML); data models and ontologies (e.g. XML-based and OWL-based languages and vocabularies). ### Important Dates Fri 9 Jun 2017 - Abstract Submission Fri 16 Jun 2017 - Paper Submission Fri 4 Aug 2017 - Author Notification Thu 10 Aug 2017 - Artifact Submission Fri 1 Sep 2017 - Artifact Notification Fri 8 Sep 2017 - Camera Ready Deadline Sun 22 Oct - SLE workshops Mon 23 Oct - Tue 24 Oct 2017 - SLE Conference ### Topics of Interest SLE aims to be broad-minded and inclusive about relevance and scope. We solicit high-quality contributions in areas ranging from theoretical and conceptual contributions to tools, techniques, and frameworks in the domain of language engineering. Topics relevant to SLE cover generic aspects of software languages development rather than aspects of engineering a specific language. In particular, SLE is interested in principled engineering approaches and techniques in the following areas: * Language Design and Implementation * Approaches and methodologies for language design * Static semantics (e.g., design rules, well-formedness constraints) * Techniques for behavioral / executable semantics * Generative approaches (incl. code synthesis, compilation) * Meta-languages, meta-tools, language workbenches * Language Validation * Verification and formal methods for languages * Testing techniques for languages * Simulation techniques for languages * Language Integration and Composition * Coordination of heterogeneous languages and tools * Mappings between languages (incl. transformation languages) * Traceability between languages * Deployment of languages to different platforms * Language Maintenance * Software language reuse * Language evolution * Language families and variability * Domain-specific approaches for any aspects of SLE (design, implementation, validation, maintenance) * Empirical evaluation and experience reports of language engineering tools * User studies evaluating usability * Performance benchmarks * Industrial applications ### Types of Submissions * **Research papers**: These should report a substantial research contribution to SLE or successful application of SLE techniques or both. Full paper submissions must not exceed 12 pages including bibliography in ACM SIGPLAN acmart conference style ( http://www.sigplan.org/Resources/Author/) * **Tool papers**: Because of SLE's interest in tools, we seek papers that present software tools related to the field of SLE. Selection criteria include originality of the tool, its innovative aspects, and relevance to SLE. Any of the SLE topics of interest are appropriate areas for tool demonstrations. Submissions must provide a tool description of 4 pages including bibliography in ACM SIGPLAN acmart conference style ( http://www.sigplan.org/Resources/Author/) and a demonstration outline including screenshots of up to 6 pages. Tool demonstrations must have the keywords âTool Demoâ or âTool Demonstrationâ in the title. The 4-page tool description will, if the demonstration is accepted, be published in the proceedings. The 6-page demonstration outline will be used by the program committee only for evaluating the submission. * **Industrial papers**: These should describe real-world application scenarios of SLE in industry, explained in their context with an analysis of the challenges that were overcome and the lessons which the audience can learn from this experience. Industry paper submissions must not exceed 6 pages including bibliography in ACM SIGPLAN acmart conference style ( http://www.sigplan.org/Resources/Author/) * **New ideas / vision papers**: New ideas papers should describe new, non-conventional SLE research approaches that depart from standard practice. They are intended to describe well-defined research ideas that are at an early stage of investigation. Vision papers are intended to present new unifying theories about existing SLE research that can lead to the development of new technologies or approaches. New ideas / vision papers must not exceed 4 pages including bibliography in ACM SIGPLAN acmart conference style (http://www.sigplan.org/Resources/Author/) ### Artifact evaluation SLE will for the second year use an evaluation process for assessing the quality of artifacts on which papers are based. The aim of this evaluation process is to foster a culture of experimental reproducibility as well as a higher quality in the research area as a whole. Authors of papers accepted for SLE 2017 will be invited to submit artifacts. Any kind of artifact that is presented in the paper, supplements the paper with further details, or underlies the paper can be submitted. This includes, for instance, tools, grammars, metamodels, models, programs, algorithms, scripts, proofs, datasets, statistical tests, checklists, surveys, interview scripts, visualizations, annotated bibliographies, and tutorials. The submitted artifacts will be reviewed by a dedicated Artifact Evaluation Committee (AEC). Artifacts that live up to the expectations created by the paper will receive a badge of approval from the AEC. The approved artifacts will be invited for inclusion in the electronic conference proceedings published in the ACM Digital Library. This will ensure the permanent and durable storage of the artifacts alongside the published papers fostering the repeatability of experiments, enabling precise comparison with alternative approaches, and helping the dissemination of the authorâs ideas in detail. Participating in the artifact evaluation and publishing approved artifacts in the ACM Digital Library is voluntary. However, we strongly encourage authors to consider this possibility as the availability of artifacts will greatly benefit readers of papers and increase the impact of the work. Note that the artifact evaluation cannot affect the acceptance of the paper, because it only happens after the decision about acceptance has been made. ### Publications All submitted papers will be reviewed by at least three members of the program committee. All accepted papers, including tool papers, industrial papers and new ideas / vision papers will be published in ACM Digital Library. Selected accepted papers will be invited to a special issue of the Computer Languages, Systems and Structures (COMLAN) journal. ### Awards * **Distinguished paper**: Award for most notable paper, as determined by the PC chairs based on the recommendations of the program committee. * **Distinguished reviewer**: Award for distinguished reviewer, as determined by the PC chairs using feedback from the authors. * **Distinguished artifact**: Award for the artifact most significantly exceeding expectations, as determined by the AEC chairs based on the recommendations of the artifact evaluation committee. ### Program Committee Marjan Mernik (co-chair), University of Maribor, Slovenia Bernhard Rumpe (co-chair), RWTH Aachen University, Germany Christian Berger, Chalmers, Sweden Mark van den Brand, TU Eindhoven, The Netherlands Ruth Breu, University of Innsbruck, Austria Jordi Cabot, ICREA, Spain Walter Cazzola, University of Milan, Italy Marsha Chechik, University of Toronto, Canada Tony Clark, Middlesex University, UK Tom Dinkelaker, Ericsson, Germany Bernd Fischer, Stellenbosch University, South Africa Sebastian Gerard, CEA, France Jeff Gray, University of Alabama, USA Esther Guerra, Autonomous University of Madrid, Spain Michael Homer, Victoria University of Wellington, New Zealand Ralf LÃ¤mmel, University of Koblenz-Landau, Germany Tihamer Levendovszky, Microsoft, USA Gunter Mussbacher, McGill University, Canada Terence Parr, University of San Francisco, USA Jaroslav PorubÃ¤n, University of KoÅ¡ice, Slovakia Jan Ringert, Tel Aviv University, Israel Julia Rubin, University of British Columbia, Canada Tony Sloane, Macquarie University, Australia Eugene Syriani, University of Montreal, Canada Emma SÃ¶derberg, Google, Denmark Eric Van Wyk, University of Minnesota, USA Jurgen Vinju, CWI, Netherlands Eric Walkingshaw, Oregon State University, USA Andreas Wortmann, RWTH Aachen University, Germany Tian Zhang, Nanjing University, China ### Contact For any question, please contact the organizers via email: sle2017(a)inria.fr

June 4, 2017

snap morphs/windows to each other when dragging

by Peter Uhnak

Hi, is it possible to tell windows to "snap" to other windows when dragging? So e.g. when I am dragging Playground window, it will try to snap side by side with a close-by another window, so they don't overlap (unless I e.g. press shift or something). Thanks, Peter

June 4, 2017

Creating a BaselineOf from a ConfigurationOf>>#baselineXyz:

by Sean P. DeNigris

I'm trying to write a rewrite rule, but can't quite get it. I first want to remove `spec blessing: #baseline.` I tried the following with no effect: RBParseTreeRewriter new replace: '`@expr blessing: `#lit' with: ''; executeTree: methodTree; tree. NB: If I try to edit the expression instead of remove, by passing something like '`@expr assert: `#lit' for #with:, it works What am I missing here? Thanks! ----- Cheers, Sean -- View this message in context: http://forum.world.st/Creating-a-BaselineOf-from-a-ConfigurationOf-baseline… Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com.

June 4, 2017

Re: [Pharo-users] Porting Transducers to Pharo

by Steffen MÃ¤rcker

Dear all, attached are updated file-outs. I fixed a couple of annoyances that slipped through yesterday evening. Most notable: 1) Random generator now works. 2) Early termination via Reduced exception does MNU anymore. 3) Printing a transducer holding a block does not MNU anymore. Please, give it a spin and tell me your impressions. (At least) The coin-flipping the example from the package comment works now: scale := [:x | (x * 2 + 1) floor] map. sides := #(heads tails) replace. count := 1000 take. collect := [:bag :c | bag add: c; yourself]. experiment := (scale * sides * count) transform: collect. "experiment cannot be re-used" samples := Random new reduce: experiment init: Bag new. "transform and reduce in one step" samples := Random new transduce: scale * sides * count reduce: collect init: Bag new. "assemble coin (eduction) and flip (reduction) objects" coin := sides <~ scale <~ Random new. flip := Bag <~ count. "flip coin =)" samples := flip <~ coin. Cheers! Steffen Am .06.2017, 23:08 Uhr, schrieb Steffen MÃ¤rcker <merkste(a)web.de>: > Thanks, this appears to work. Attached you'll find the file-out from > VisualWorks and the file-out from Pharo (includes package comment). > > Cheers! > Steffen > > > Am .06.2017, 20:06 Uhr, schrieb Yanni Chiu <yanni.code(a)gmail.com>: > >> To get the extension methods into the Transducers package, the following >> worked for me - edit the category to have the prefix '*Transducers-' >> >> 2710c2710 >> >> < !Number methodsFor: 'transforming' stamp: ' 2/6/17 15:38'! >> >> --- >> >>> !Number methodsFor: '*Transducers-transforming' stamp: ' 2/6/17 15:38'! >> >> >> On Fri, Jun 2, 2017 at 11:05 AM, Steffen MÃ¤rcker <merkste(a)web.de> wrote: >> >>> Dear all, >>> >>> thanks for the many suggestions. I didn't had time to test all >>> import/export ways yet. But for now, I can report on two: >>> >>> 1) NGFileOuter >>> Unfortunately It raised several MNUs in my image. I'll investigate them >>> later. >>> >>> 2) FileOut30 (VW Contributed) >>> I was able to file out the code except for the package definition. >>> Replacing {category: ''} in the class definitions with {package: >>> 'Transducers'} fixed that. However, methods that extend existing >>> classes >>> did not end up in the Transducers package. Is there a similar easy >>> change >>> to the file-out making that happen? Also I'd like to add the package >>> comment if that's possible. >>> >>> Most things appear to work as far as I can see. Two exceptions: >>> 1) Random is a subclass of Stream in VW and in Pharo it is not. Hence, >>> I'll have to copy some methods from Stream to Random. >>> 2) I used #beImmutable in VW but I couldn't yet figure out how to make >>> objects immutable in Pharo. >>> >>> However, until the tests are ported, I cannot guarantee. Porting the >>> test >>> suite will be another beast, since I rely on the excellent >>> mocking/stubbing >>> library DoubleAgents by Randy Coulman. I am not sure how I will handle >>> that. In general, I think it would be really worth the effort to be >>> ported >>> to Pharo, too. DoubleAgents is pretty powerful and produces easy to >>> read >>> and understand mocking/stubbing code. Personally, I prefer it clearly, >>> e.g., over Mocketry (no offence intended!). >>> >>> Attached you'll find the file-out that I loaded into Pharo. The issues >>> above are not addressed yet. However, the following example works: >>> >>> | scale sides count collect experiment random samples coin flip | >>> scale := [:x | (x * 2 + 1) floor] map. >>> sides := #(heads tails) replace. >>> count := 1000 take. >>> collect := [:bag :c | bag add: c; yourself]. >>> experiment := (scale * sides * count) transform: collect. >>> random := #(0.1 0.3 0.4 0.5 0.6 0.7 0.8 0.9). >>> >>> samples := random >>> reduce: experiment >>> init: Bag new. >>> >>> samples := random >>> transduce: scale * sides * count >>> reduce: collect >>> init: Bag new. >>> >>> coin := sides <~ scale <~ random. >>> flip := Bag <~ count. >>> >>> samples := flip <~ coin. >>> >>> >>> Best, Steffen >>> >>> >>> >>> Am .06.2017, 08:16 Uhr, schrieb Stephane Ducasse >>> <stepharo.self(a)gmail.com >>> >: >>> >>> There is a package for that NGFileOuter or something like that on >>> cincom >>>> store. >>>> We used it for mobydic code. >>>> >>>> On Wed, May 31, 2017 at 6:35 PM, Alexandre Bergel < >>>> alexandre.bergel(a)me.com> >>>> wrote: >>>> >>>> If I remember correctly, there is a parcel in VisualWorks to export a >>>> file >>>>> out (Squeak format). >>>>> >>>>> @Milton, can you give a hand to Steffen? >>>>> >>>>> Alexandre >>>>> -- >>>>> _,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;: >>>>> Alexandre Bergel http://www.bergel.eu >>>>> ^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;. >>>>> >>>>> >>>>> >>>>> On May 31, 2017, at 10:32 AM, Steffen MÃ¤rcker <merkste(a)web.de> wrote: >>>>> >>>>> Thanks for the encouraging response! First question: Which is the >>>>> recommended (friction free) way to exchange code between VW and >>>>> Pharo? >>>>> >>>>> Cheers! >>>>> Steffen >>>>> >>>>> Am .05.2017, 16:22 Uhr, schrieb Alexandre Bergel < >>>>> alexandre.bergel(a)me.com >>>>> >: >>>>> >>>>> I second Sven. This is very exciting! >>>>> >>>>> Let us know when you have something ready to be tested. >>>>> >>>>> Alexandre >>>>> >>>>>

June 3, 2017

Re: Morphic or forking bug?

by Milan Vavra

Sven's Clock example. Just unzip & file in. MyClock.zip <http://forum.world.st/file/n4949170/MyClock.zip> Best Regards, Milan Vavra -- View this message in context: http://forum.world.st/Morphic-or-forking-bug-tp4948727p4949170.html Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com.

June 3, 2017

Re: [Pharo-users] Morphic or forking bug?

by horrido

Okay, let me explain my application... It displays a Morphic window containing lines of information that are updateable in real time on a periodic basis. As I indicated in the original post, the code skeleton is basically: initA a := ((StringMorph contents: '####') color: Color white) position: (0@0). m addMorph: a initialize f := Form fromFileNamed: 'hot_air_balloon_mysticmorning.jpg'. m := ImageMorph new. m form: f. self initA. m openInWindowLabeled: 'Cranky'. delay := (Delay forSeconds: 5). [ [ true ] whileTrue: [ a contents: 0 asString. delay wait ] fork Imagine that #initA creates many such StringMorphs, each displaying a different kind of information. In the endless loop, imagine that instead of 'a contents: 0 asString', I'm updating all of the StringMorphs I created in #initA. The need to do this in a separate thread is to prevent Pharo from being completely frozen during the 'delay wait', which is practically all the time! Now, I did try Hilaire's suggestion to use Morphic's step protocol instead. But in my test scenario of closing the app/saving and exiting the image/restarting the image, repeatedly (in may take 10-20 times), it still causes the occasional segmentation fault. So if the problem is updating a structure in the main thread from another process, then why did Hilaire's suggestion not solve the problem? It seems to me, then, either way, it's an issue of multithreading...whether my way or Hilaire's way. Sven Van Caekenberghe-2 wrote > Hi Horrido, > > It is very hard to follow what you are exactly doing or trying to do. > > Here is the simplest example I can think of that updates something in > Morphic on a regular basis. > > StringMorph subclass: #MyClock > instanceVariableNames: '' > classVariableNames: '' > package: '_UnpackagedPackage' > > MyClock>>#initialize > super initialize. > self updateClock > > MyClock>>#step > self updateClock > > MyClock>>#updateClock > self contents: Time now printString > > MyClock class>>#open > "self open" > > ^ self new openInWindow > > This inherits #stepTime as 1 second. If I open such a window and save my > image, it is still there when the image is restarted, with the clock still > working. > > Updating (data structures in) the main UI process from another process is > dangerous. Saving such constructs is even more dangerous. > > HTH, > > Sven > >> On 2 Jun 2017, at 15:54, horrido < > horrido.hobbies@ > > wrote: >> >> Sorry, I could be mistaken. I just checked my notes. The *0 asString* >> test >> failed once, but I've not been able to replicate it. I might've been >> working >> with an unclean image. >> >> So perhaps it is related to Morphic, after all. >> >> >> horrido wrote >>> Yup, they all fail. Interesting that >> * >>> 0 asString >> * >>> fails. This means it has NOTHING to do with Morphic (or Morphic being >>> thread-unsafe). >>> >>> Ben Coman wrote >>>> On Wed, May 31, 2017 at 10:23 PM, horrido < >> >>>> horrido.hobbies@ >> >>>> > wrote: >>>> >>>> Can you try a few other variations... >>>> [ [ true ] whileTrue: [ 0 asString. delay wait ] fork. >>>> [ [ true ] whileTrue: [ a contents: '0'. delay wait ] fork. >>>> [ [ true ] whileTrue: [ a contents: '0'. ] forkAt: 20. >>>> >>>> cheers -ben >> >> >> >> >> >> -- >> View this message in context: >> http://forum.world.st/Morphic-or-forking-bug-tp4948727p4948984.html >> Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com. -- View this message in context: http://forum.world.st/Morphic-or-forking-bug-tp4948727p4949166.html Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com.

June 3, 2017