January 2019 - Pharo-users - lists.pharo.org

Re: [Pharo-users] Transforming objects

by LoÃ¯c PagÃ¨s

Hi Esteban, In the present model, the plant has a tree-like structure. It is a well suited structure, even for a dandelion since the leaves are connected on a shoot. The plant root system has a tree structure as well ! Thank you, LoÃ¯c Le 16/01/2019 Ã 13:52, Esteban Maringolo a Ã©critÂ : > This is a challenging modelling issue, life progress or any other > dissipative/emergent structure are "restricted" by the boundaries of > your objects (e.g. if you model a flock, and it divides into two > flocks, and then merges again, which flock remains? Note: I wouldn't > model the Flock at all). > > So it is hard to advice without knowing exactly what the use case is > or how the simulation is done,Â but in the past I had to model a > non-organic tree structure that was changing on a daily basis, where > each part had it's own attributes and we should be able to query (aka > "reconstruct") the "tree structure" at any point in time and query > specific parts history, my solution to that was to have an "invariant" > identity (E.g. "Plant #1234") and a subtree of elements, where each > child wasn't the "organ" directly, but a "node" that contains the > "organ" with a starting and an end date (like Joachim suggested) and > know the parent "organ" (or the plant itself). In your case, the > organs are not going to be transplanted (as was in my case), so the > organ/node could be merged into one, which simplifies everything. > > I don't know if your model has a tree like structure, whether it's a > lemon tree or just a dandelion :), so I don't know if, e.g., the > flower contains the fruit, or as I understand biology, the plant > contains the flower until some point where it stops being a flower and > then you replace it by a fruit. > > I hope it helps you. > > > Esteban A. Maringolo > > > El miÃ©., 16 ene. 2019 a las 9:19, Richard O'Keefe (<raoknz(a)gmail.com > <mailto:raoknz@gmail.com>>) escribiÃ³: > > It seems to me that in the real world, a bud does not get replaced > by a flower > nor a flower by a fruit, nor is there a definite point at which a > thing stops > being a bud and starts being a flower, and so on.Â It's summer > now, but spring > wasn't that long ago, and I enjoyed watching the imperceptible > *continuous* > changes.Â So anything you do is going to be imposing discontinuity > on a more- > or-less continuous process and is definitely going to be an > approximation. > > You may perhaps be looking for the "State" design pattern where > there is an > object with a fixed identity (*this* bud/flower/fruit) which behaves > differently at different times, and this is modelled by the > "outer" object > delegating some of its behaviour to a "state" which can be replaced. > So you would have > Â PlantOrgan > PlantReproductiveOrgan (state) > > PlantReproductiveOrganState > Â Â Bud > Â Â Flower > Â Â DeadFlower > Â Â ImmatureFruit > Â Â MatureFruit > > You will find abundant material about the "State" design pattern > on the web. > > > On Thu, 17 Jan 2019 at 00:29, LoÃ¯c PagÃ¨s <loic.pages(a)inra.fr > <mailto:loic.pages@inra.fr>> wrote: > > Hi Joachim, > > Thank you for your reply and for your ideas. I will reply to your > questions below. > > Le 16/01/2019 Ã 10:25, jtuchel(a)objektfabrik.de > <mailto:jtuchel@objektfabrik.de> a Ã©critÂ : > > LoÃ¯c, > > > > Am I correct in assuming you are thinking about a model in > which a > > plant can have a growing and shrinking list of organs over > time and > > some of them even have (a growing list of) stages? > > Yes, the plant can be seen as a growing and shrinking list of > organs. > Very short list at the beginning, and becoming larger. Some > organs can > fall (leaves, roots) or even be pruned (shoots in fruit > trees), so that > shrinking can also occur. > > However, the list of stages for each organ is usually known at > the > beginning, for each type of organ. It depends of knowledge and > level of > detail that we include in the model. > > > > > I am not an expert on the matter, but to me the stages idea > sounds > > good. It even allows for historic information (it was a bud > from Date1 > > to Date2 and since then it is a flower). So transformation > would be > > adding a new Stage and "terminate" the previous one. > > This can be an approach. But the conditions for passing from > one stage > to another can be more complex and involve several aspects (age, > previous growth, pollination, etc) with a lot of code. So, if > you keep > this code into the general "reproductive organ" class, you > make a "fat > class" with a lot of tests. This was not recommended in the > Pharo course > :-) > > > > > With this you can ask a plant about its current stage on the > > reproductive front and maybe other organs as well at any > point time. > > This may be helpful if you want to build an animation of the > plant's > > development over time. You can have separate life cycles for > each organ. > This is actually an objective of such models, to be able to > get the > status of the whole plant, regarding the stages of organs. > > > > Does the plant transform in the real world? I mean, is a > cherry tree > > still a cherry tree, even if it's not blooming any more and > carries > > fruit instead? So why transform the object in its abstract > model? > The plant usually changes because of its development, but a > cherry tree > remains a cherry tree !Â And flowers are necessary steps to > get fruits > !Â The idea was not to transform the whole plant, but each > individual > organ that it carries. > > > > > > Just a thought, maybe better ideas show up. > > OK, thank you again > > LoÃ¯c > > > > > > > > > Am 16.01.19 um 10:15 schrieb LoÃ¯c PagÃ¨s: > >> Dear Pharo users, > >> > >> I develop software dedicated to the simulation of plant > development > >> and 3D architecture. > >> > >> In the past, I used Java, but I am very interested in > translating > >> code in Pharo. I appreciated very much the language and the > course. > >> > >> I have a question for you all : > >> > >> During plant development (ontogeny), new organs appear, > that are > >> gradually tranformed. For example, a bud can make a flower, > and then > >> a fruit. > >> > >> Organs are conveniently modelled as classes. During the > course, I > >> learned that it was better to make several classes (bud, > flower, > >> fruit) instead of a "fat class" such as "reproductive > organ" with > >> many attributes and stages (bud stage, flower stage, fruit > stage). I > >> wonder how to transform an object into another one, to > represent for > >> example the fact that the flower may become a fruit. > >> > >> Maybe a naive question ? > >> > >> Thanks for your lights ! > >> > >> LoÃ¯c > >> > >> > >> > >> > > > > > >

Jan. 16, 2019

Re: [Pharo-users] [ANN] SETT (Store Export to Tonel Tools) for Pharo6.1

by Dale Henrichs

On 1/16/19 11:56 AM, Esteban Maringolo wrote: > This is great! > > One less fence to move code from one dialect to another. :) > > I will follow the examples and try to export code from Store and load > id in Pharo. > > Is it mandatory to use Linux? We've only tested with Linux and it looks like the current code base is wired to use Unix[1] .... Dale [1] https://github.com/GemTalk/SETT/blob/master/StoreImporter.package/SettGitRe… > > Esteban A. Maringolo > > > El miÃ©., 16 ene. 2019 a las 16:38, Dale Henrichs > (<dale.henrichs(a)gemtalksystems.com > <mailto:dale.henrichs@gemtalksystems.com>>) escribiÃ³: > > GemTalkSystems is pleased to announce SETT (Store Export to Tonel > Tools)[1]. SETT is open source project with an MIT license. > > SETT (Store Export to Tonel Tools) is a set of tools to export > Smalltalk code from Store and > write into the Tonel file format managed using Git. > > SETT is: > > * a Pharo 6.1 application, that > * connects to a Postgres Database > * containing source code history in VisualWorks Store format; and > * writes to a Git repository > * in Tonel format > * maintaining all version history, source code and SCM metadata. > > SETT was developed last year to support one of our commercial > customers in their conversion From Store to Rowan[2]. Rowan > artifacts are produced as part of the output of SETT, but the > Rowan artifacts can be ignored. The important bit is that SETT > converts from Store to Tonel and maintains version history in git. > > Please see the project ReadMe[3] and Wiki[4] for additional details. > > Dale > > [1] https://github.com/GemTalk/SETT > [2] https://github.com/GemTalk/Rowan > [3] https://github.com/GemTalk/SETT#overview > [4] https://github.com/GemTalk/SETT/wiki > >

Jan. 16, 2019

Re: [Pharo-users] [ANN] SETT (Store Export to Tonel Tools) for Pharo6.1

by Esteban Maringolo

This is great! One less fence to move code from one dialect to another. :) I will follow the examples and try to export code from Store and load id in Pharo. Is it mandatory to use Linux? Esteban A. Maringolo El miÃ©., 16 ene. 2019 a las 16:38, Dale Henrichs (< dale.henrichs(a)gemtalksystems.com>) escribiÃ³: > GemTalkSystems is pleased to announce SETT (Store Export to Tonel > Tools)[1]. SETT is open source project with an MIT license. > > SETT (Store Export to Tonel Tools) is a set of tools to export Smalltalk > code from Store and > write into the Tonel file format managed using Git. > > SETT is: > > - a Pharo 6.1 application, that > - connects to a Postgres Database > - containing source code history in VisualWorks Store format; and > - writes to a Git repository > - in Tonel format > - maintaining all version history, source code and SCM metadata. > > SETT was developed last year to support one of our commercial customers in > their conversion From Store to Rowan[2]. Rowan artifacts are produced as > part of the output of SETT, but the Rowan artifacts can be ignored. The > important bit is that SETT converts from Store to Tonel and maintains > version history in git. > > Please see the project ReadMe[3] and Wiki[4] for additional details. > > Dale > [1] https://github.com/GemTalk/SETT > [2] https://github.com/GemTalk/Rowan > [3] https://github.com/GemTalk/SETT#overview > [4] https://github.com/GemTalk/SETT/wiki > > >

Jan. 16, 2019

[ANN] SETT (Store Export to Tonel Tools) for Pharo6.1

by Dale Henrichs

GemTalkSystems is pleased to announce SETT (Store Export to Tonel Tools)[1]. SETT is open source project with an MIT license. SETT (Store Export to Tonel Tools) is a set of tools to export Smalltalk code from Store and write into the Tonel file format managed using Git. SETT is: * a Pharo 6.1 application, that * connects to a Postgres Database * containing source code history in VisualWorks Store format; and * writes to a Git repository * in Tonel format * maintaining all version history, source code and SCM metadata. SETT was developed last year to support one of our commercial customers in their conversion From Store to Rowan[2]. Rowan artifacts are produced as part of the output of SETT, but the Rowan artifacts can be ignored. The important bit is that SETT converts from Store to Tonel and maintains version history in git. Please see the project ReadMe[3] and Wiki[4] for additional details. Dale [1] https://github.com/GemTalk/SETT [2] https://github.com/GemTalk/Rowan [3] https://github.com/GemTalk/SETT#overview [4] https://github.com/GemTalk/SETT/wiki

Jan. 16, 2019

Re: [Pharo-users] Transforming objects

by Jose San Leandro

Being a fan of DDD and Event Sourcing as I am, I'd implement your domain using Aggregates and Events. Basically, your aggregate (Plant?) would respond to external information (or based on a schedule) and as a result, new events are generated ("Flower sprung", "Plant died", ...). If only we had properly documented our Pharo-EDA "framework"... https://github.com/osoco/pharo-eda El miÃ©., 16 ene. 2019 a las 18:05, LoÃ¯c PagÃ¨s (<loic.pages(a)inra.fr>) escribiÃ³: > Hi Richard, > > You are in the south hemisphere, so ! Temperatures are low here in France. > > Thank you for your comments. > I agree that development is slow if you look at the plant every day, and > in this case we perceive continuous changes. But in models, it might be > convenient to define discrete stages. If you look at a flower bud at a > given date and come back several days (or weeks) after, you can see a > flower at the bud location. This type of approximation is usual in > biological modelling and data acquisition. > > Thank you for the suggestions on the "State" design pattern. I will have a > look ! > > LoÃ¯c > > Le 16/01/2019 Ã 13:18, Richard O'Keefe a Ã©crit : > > It seems to me that in the real world, a bud does not get replaced by a > flower > nor a flower by a fruit, nor is there a definite point at which a thing > stops > being a bud and starts being a flower, and so on. It's summer now, but > spring > wasn't that long ago, and I enjoyed watching the imperceptible *continuous* > changes. So anything you do is going to be imposing discontinuity on a > more- > or-less continuous process and is definitely going to be an approximation. > > You may perhaps be looking for the "State" design pattern where there is an > object with a fixed identity (*this* bud/flower/fruit) which behaves > differently at different times, and this is modelled by the "outer" object > delegating some of its behaviour to a "state" which can be replaced. > So you would have > PlantOrgan > PlantReproductiveOrgan (state) > > PlantReproductiveOrganState > Bud > Flower > DeadFlower > ImmatureFruit > MatureFruit > > You will find abundant material about the "State" design pattern on the > web. > > > On Thu, 17 Jan 2019 at 00:29, LoÃ¯c PagÃ¨s <loic.pages(a)inra.fr> wrote: > >> Hi Joachim, >> >> Thank you for your reply and for your ideas. I will reply to your >> questions below. >> >> Le 16/01/2019 Ã 10:25, jtuchel(a)objektfabrik.de a Ã©crit : >> > LoÃ¯c, >> > >> > Am I correct in assuming you are thinking about a model in which a >> > plant can have a growing and shrinking list of organs over time and >> > some of them even have (a growing list of) stages? >> >> Yes, the plant can be seen as a growing and shrinking list of organs. >> Very short list at the beginning, and becoming larger. Some organs can >> fall (leaves, roots) or even be pruned (shoots in fruit trees), so that >> shrinking can also occur. >> >> However, the list of stages for each organ is usually known at the >> beginning, for each type of organ. It depends of knowledge and level of >> detail that we include in the model. >> >> > >> > I am not an expert on the matter, but to me the stages idea sounds >> > good. It even allows for historic information (it was a bud from Date1 >> > to Date2 and since then it is a flower). So transformation would be >> > adding a new Stage and "terminate" the previous one. >> >> This can be an approach. But the conditions for passing from one stage >> to another can be more complex and involve several aspects (age, >> previous growth, pollination, etc) with a lot of code. So, if you keep >> this code into the general "reproductive organ" class, you make a "fat >> class" with a lot of tests. This was not recommended in the Pharo course >> :-) >> >> > >> > With this you can ask a plant about its current stage on the >> > reproductive front and maybe other organs as well at any point time. >> > This may be helpful if you want to build an animation of the plant's >> > development over time. You can have separate life cycles for each organ. >> This is actually an objective of such models, to be able to get the >> status of the whole plant, regarding the stages of organs. >> > >> > Does the plant transform in the real world? I mean, is a cherry tree >> > still a cherry tree, even if it's not blooming any more and carries >> > fruit instead? So why transform the object in its abstract model? >> The plant usually changes because of its development, but a cherry tree >> remains a cherry tree ! And flowers are necessary steps to get fruits >> ! The idea was not to transform the whole plant, but each individual >> organ that it carries. >> > >> > >> > Just a thought, maybe better ideas show up. >> >> OK, thank you again >> >> LoÃ¯c >> >> > >> > >> > >> > Am 16.01.19 um 10:15 schrieb LoÃ¯c PagÃ¨s: >> >> Dear Pharo users, >> >> >> >> I develop software dedicated to the simulation of plant development >> >> and 3D architecture. >> >> >> >> In the past, I used Java, but I am very interested in translating >> >> code in Pharo. I appreciated very much the language and the course. >> >> >> >> I have a question for you all : >> >> >> >> During plant development (ontogeny), new organs appear, that are >> >> gradually tranformed. For example, a bud can make a flower, and then >> >> a fruit. >> >> >> >> Organs are conveniently modelled as classes. During the course, I >> >> learned that it was better to make several classes (bud, flower, >> >> fruit) instead of a "fat class" such as "reproductive organ" with >> >> many attributes and stages (bud stage, flower stage, fruit stage). I >> >> wonder how to transform an object into another one, to represent for >> >> example the fact that the flower may become a fruit. >> >> >> >> Maybe a naive question ? >> >> >> >> Thanks for your lights ! >> >> >> >> LoÃ¯c >> >> >> >> >> >> >> >> >> > >> > >> >> >> >

Jan. 16, 2019

Re: [Pharo-users] Transforming objects

by Joachim Tuchel

+1 about become: Donât use it for business stuff. Plus it can be very problematic when it comes to persistence mechanisms like O/R mappers... > Am 16.01.2019 um 19:01 schrieb Esteban Maringolo <emaringolo(a)gmail.com>: > >> El miÃ©., 16 ene. 2019 a las 14:49, Ben Coman via Pharo-users (<pharo-users(a)lists.pharo.org>) escribiÃ³: > >> >> >>> On Wed, 16 Jan 2019 at 17:16, LoÃ¯c PagÃ¨s <loic.pages(a)inra.fr> wrote: >>> >>> Maybe a naive question ? >> >> Maybe #become: ... >> https://gbracha.blogspot.com/2009/07/miracle-of-become.html >> > > Although miraculous, using #become: to model a business domain is harmful, and has more undesired side effects than benefits. > > So I would save it to a very limited use case scenarios, which are more related with low level stuff. > > Esteban A. Maringolo > >

Jan. 16, 2019

Re: [Pharo-users] Transforming objects

by Esteban Maringolo

El miÃ©., 16 ene. 2019 a las 14:49, Ben Coman via Pharo-users (< pharo-users(a)lists.pharo.org>) escribiÃ³: > > > On Wed, 16 Jan 2019 at 17:16, LoÃ¯c PagÃ¨s <loic.pages(a)inra.fr> wrote: > >> >> Maybe a naive question ? >> > > Maybe #become: ... > https://gbracha.blogspot.com/2009/07/miracle-of-become.html > > Although miraculous, using #become: to model a business domain is harmful, and has more undesired side effects than benefits. So I would save it to a very limited use case scenarios, which are more related with low level stuff. Esteban A. Maringolo

Jan. 16, 2019

Re: [Pharo-users] adding instance variables (data) to the Object class

by Stephan Eggermont

Petr Fischer via Pharo-users <pharo-users(a)lists.pharo.org> wrote: Hello! Weird question: why I can't add instance variables to the Object class (for example "oid" or something else)? Is it due to some internal (and different) VM "class layouts"? Or - can I inject my own information to all existing objects (any class)? You might want to take a look at the documentation of Magma. http://wiki.squeak.org/squeak/2665 Stephan

Jan. 16, 2019

Re: [Pharo-users] adding instance variables (data) to the Object class

by Benoit St-Jean

Petr, Since you seem to want to add this (these) extra instance variable(s) in the context of some kind of persistence (objects being retrieved/created from/to some kind of database), perhaps subclassing all your objects from a PersistentObject class (that inherits from Object) would be the simplest solution.

Jan. 16, 2019

Re: [Pharo-users] Transforming objects

by Richard Sargent

On Wed, Jan 16, 2019 at 9:05 AM LoÃ¯c PagÃ¨s <loic.pages(a)inra.fr> wrote: > Hi Richard, > > You are in the south hemisphere, so ! Temperatures are low here in France. > > Thank you for your comments. > I agree that development is slow if you look at the plant every day, and > in this case we perceive continuous changes. But in models, it might be > convenient to define discrete stages. If you look at a flower bud at a > given date and come back several days (or weeks) after, you can see a > flower at the bud location. This type of approximation is usual in > biological modelling and data acquisition. > > Thank you for the suggestions on the "State" design pattern. I will have a > look ! > LoÃ¯c, the state pattern is one form of composition. You may want to formally model the stages as named attributes or a collection, rather than something that "loses history". (The 0, 1, infinity guideline suggests a collection of stages is more likely the way to go.) Whether all the stages are in the collection from the beginning or whether each as added as development reaches that point is an open question. e.g. (stages at: stage) versus (stages last) to access the "state" in a state pattern implementation. > > LoÃ¯c > > Le 16/01/2019 Ã 13:18, Richard O'Keefe a Ã©crit : > > It seems to me that in the real world, a bud does not get replaced by a > flower > nor a flower by a fruit, nor is there a definite point at which a thing > stops > being a bud and starts being a flower, and so on. It's summer now, but > spring > wasn't that long ago, and I enjoyed watching the imperceptible *continuous* > changes. So anything you do is going to be imposing discontinuity on a > more- > or-less continuous process and is definitely going to be an approximation. > > You may perhaps be looking for the "State" design pattern where there is an > object with a fixed identity (*this* bud/flower/fruit) which behaves > differently at different times, and this is modelled by the "outer" object > delegating some of its behaviour to a "state" which can be replaced. > So you would have > PlantOrgan > PlantReproductiveOrgan (state) > > PlantReproductiveOrganState > Bud > Flower > DeadFlower > ImmatureFruit > MatureFruit > > You will find abundant material about the "State" design pattern on the > web. > > > On Thu, 17 Jan 2019 at 00:29, LoÃ¯c PagÃ¨s <loic.pages(a)inra.fr> wrote: > >> Hi Joachim, >> >> Thank you for your reply and for your ideas. I will reply to your >> questions below. >> >> Le 16/01/2019 Ã 10:25, jtuchel(a)objektfabrik.de a Ã©crit : >> > LoÃ¯c, >> > >> > Am I correct in assuming you are thinking about a model in which a >> > plant can have a growing and shrinking list of organs over time and >> > some of them even have (a growing list of) stages? >> >> Yes, the plant can be seen as a growing and shrinking list of organs. >> Very short list at the beginning, and becoming larger. Some organs can >> fall (leaves, roots) or even be pruned (shoots in fruit trees), so that >> shrinking can also occur. >> >> However, the list of stages for each organ is usually known at the >> beginning, for each type of organ. It depends of knowledge and level of >> detail that we include in the model. >> >> > >> > I am not an expert on the matter, but to me the stages idea sounds >> > good. It even allows for historic information (it was a bud from Date1 >> > to Date2 and since then it is a flower). So transformation would be >> > adding a new Stage and "terminate" the previous one. >> >> This can be an approach. But the conditions for passing from one stage >> to another can be more complex and involve several aspects (age, >> previous growth, pollination, etc) with a lot of code. So, if you keep >> this code into the general "reproductive organ" class, you make a "fat >> class" with a lot of tests. This was not recommended in the Pharo course >> :-) >> >> > >> > With this you can ask a plant about its current stage on the >> > reproductive front and maybe other organs as well at any point time. >> > This may be helpful if you want to build an animation of the plant's >> > development over time. You can have separate life cycles for each organ. >> This is actually an objective of such models, to be able to get the >> status of the whole plant, regarding the stages of organs. >> > >> > Does the plant transform in the real world? I mean, is a cherry tree >> > still a cherry tree, even if it's not blooming any more and carries >> > fruit instead? So why transform the object in its abstract model? >> The plant usually changes because of its development, but a cherry tree >> remains a cherry tree ! And flowers are necessary steps to get fruits >> ! The idea was not to transform the whole plant, but each individual >> organ that it carries. >> > >> > >> > Just a thought, maybe better ideas show up. >> >> OK, thank you again >> >> LoÃ¯c >> >> > >> > >> > >> > Am 16.01.19 um 10:15 schrieb LoÃ¯c PagÃ¨s: >> >> Dear Pharo users, >> >> >> >> I develop software dedicated to the simulation of plant development >> >> and 3D architecture. >> >> >> >> In the past, I used Java, but I am very interested in translating >> >> code in Pharo. I appreciated very much the language and the course. >> >> >> >> I have a question for you all : >> >> >> >> During plant development (ontogeny), new organs appear, that are >> >> gradually tranformed. For example, a bud can make a flower, and then >> >> a fruit. >> >> >> >> Organs are conveniently modelled as classes. During the course, I >> >> learned that it was better to make several classes (bud, flower, >> >> fruit) instead of a "fat class" such as "reproductive organ" with >> >> many attributes and stages (bud stage, flower stage, fruit stage). I >> >> wonder how to transform an object into another one, to represent for >> >> example the fact that the flower may become a fruit. >> >> >> >> Maybe a naive question ? >> >> >> >> Thanks for your lights ! >> >> >> >> LoÃ¯c >> >> >> >> >> >> >> >> >> > >> > >> >> >> >

Jan. 16, 2019