December 2019 - Pharo-users

Code overview - or maybe not
by Kasper Osterbye Jan. 7, 2020

Jan. 7, 2020

In an other thread Steve Davies mentions that Pharo can be a bit overwhelming. Indeed I have had the same feeling. I was struggling for weeks (not every day, but still) to find out how to change the system to be able to give background color to text. As part of my attempt at understanding the code, I ended up looking at Rubric and its Text morphs. I have been working at building a little tool which can help me get an overview of the objects and how the are connected. Not a static code analysis, but a snapshot view. What I did was I took a root object, and made the transitive object closure from that object, with the following restrictions: - Only Rubric, Morphic and Collections are examined, though Strings are excluded - Only instance variables which has a selector of the same name are included - The same object only appear once in the diagram, but more than one instance of a class can be present (at different places). I build on a tool named PlantUML. When I bring up the morphic halo on a playground and select "inspect morph", and then draw the diagram for that morph, I get this diagram <https://www.plantuml.com/plantuml/svg/ZLfFZzks4h_lfp1oUdieG54aHVNmq6IJea4RTD4jyCvQMzdLYsmPifncltr7iZYS6L7hFHamvpSav_yCzSjfgFhXl6zlRePcQEjDjVdh_FYmxRkshNT_rp-6Brr_VFvFMPQkB4gjRczkkiV_rzjXymu8Hu8_caFzRbETDl2_YgiJxjEFeJwSckuG26pkjRVAkaZuULyzrHDr8CfANIXTQCBjOL-rxUTTVO1JldnijWFmhFeNH3YTErFc1F6-xwkuNkIPCzOOTlhxgg-U-YfkN7ezxgpygvSioB6wVgXtTwEmfYC54cTrcIdA9oqEu-6MPUdvkO2ihnxgcUV7UjlrrT3rU1cL5IhF2otPDzjFtq52lrM7NLiZUPvRwtFZ_MiYBvGj2bLOlIP02n8i7HVCmtDt7Xw65zXiSSZ2gp8hbL4CyNxNzOSzdF5ZSpgsrKiyfSkpJ9VAYnr6jGzL--tJhY7CTUwjpfoY1d84yb-Rm-wl6XXlwuUw_zviKMSQZACq9jUC_TqpMC1sgFiFRRVzXWBBR6P052fz572EvZWqXwSltIxQXFMbjKpZJ7wkp7AjnUtk-sOFHeoQPXh9jNCP75fViw7IUsrqLhYhlcUiTuxf-4FNx-g-th6TdIjDgHX3RWjWJUF9hbktjc1NeAWt-x4VUSC9kPf6vOEyt_TrXPS66bCo2n0E3oSqnfbhPzJEP8Mn2p6dVQai2rTgLrnLIcvL3YQNhVgJCOK7dypVB1fjGU9PvkqYDbryOxDjgzCfXj2iB6Yu-tmurSD5tQXdOvJsJikWlH96HlVtXI8y7vhziQq5Ks_17Dz0G-xnTryTJb-xVl-_PdZ-etg1gC9T8IyLE8-vQd3WCva2DnUUEsMp3nNkR_8yywQWqIpf20QIbJ9BRQS5117CGc2wQd7UALU2s2LXcglFbGTDqi2Ii0qu9fXnocaUXch0A6L1FCxAT7DtxdlOU4nn8AH59BTPNkQ5k-vAESZAAUFLma8l6hYlOWw5U0WUuWkzeBthziVkL9DORyinVRybSfUb0grcYyIO28KcSw2hg_NAI6Co5iBIX4v1ndEiPk4E3oBaYPwP6cZ6-epLHQyPXGUTA1QqKdPU571opvBUdnSpNrOi6hQ7KAYjD8qJAJp03g7EkYfTIFsk04DpL_mBYgJIvdejP-eCXAQqMHFfMAkz8d1OXg11DRSiA6JGr4hRjsShS2KrnkGrfMOsLndtz7ISKTvOiF3LYrfWevay-Rg3h6cKusxzvx4-G02uQxiJ_7oissRV38bApKBjx8j5RITRWEXZSoVmjeIf8C6wmbyJ0TIqKCDxLY6nEqB5aOqzmQgsBRYGfo9QDVMYo0jhYwlnp07BqIMkrpaEQcSk_qiMk--xOzqFJOqc1YMB6sjn8hrNKZwKn4gfh7opHHe3BGml4fBYXcgqrBbwOsOhNGvk3qvzJH15viUOCv5X4xTvbxtR_FJJVxcbCugVDzdjflldKFVJ_w5P2wZOd7IaHwDyOpd8A2Q-0rZmM3eAi4Pmp302h6ytspaRtNIngGkusB9qf9DZrqLrC8hBTOVdkey6SjFHneuoYVx9IIOk1xZS3HKHsnxh5qOXf3rtTd6xa8aIYqn_sEAnqsArm2ZOOL5m51XhDqOn0UjWQ08TTHYZaa1hSbLi6rTD9r8iJ8U0YUcWXmemRBkhlrRdTlYzVjbNnoE4uC-7NVr3iCeZA-nG1QlyTlDrqTUEHDYdqkieleBN6AkxIIMXKLsLGQHOo21qiKaSDgoKSomh6CN4-Vje-TkBwHEmJX-BWZK_5W57USOoMu1pOKy4RQvlROWzOUVDP8aHdb5CDsv5LX1CuirZPI6Ow6JW83oY0EPEJ320spzE6M6QsuohE1QWjvXRDBOyNM4T74yV9qu23wUlINwPJ2eC6-Zk8O-mzKGaYDYuUIow19f60fnCq5tZy85Hh4LhD14cD-nh6CN4uuHTa83hT12WSBqM10YRgFeuZH9iHjk_z8NZy4hWe_N7mOt06w41WhOhoPYWxUtcgHw-r8VpVTSssnV1mKKTXaP3C72GaAUEH22BY9nBU04iBlVk-hkntXTe7-M6Gqk1zxUROnWM2tH9p3wCAGIwf363M8qYEJuqvj9i56fiwkGb2n9fSIOgMMJXyX9Cx6vkfIGKpEvqVjoFnTwbGWbZDRHtd1LsP9QsY2I6BwSY2G6JE1XcAWAU22GuSKjl7fTJcnCmhId2i4_W4xlFypPMVOMEXInVui3vSMexvymNh4Q4aSkuc144TDG70STpnqS5WTOoyqLqdevW59tJ-1acQFJG-4R029Q79c1DFI2MdHIjHzTxciU_0XvFZQC4WOP3dzfcjpYrIT-NGY7MxI58jW9fIP8E_Q50MY5dhCEPjF19Yb6an8Leuh0ujXPegME29la11qC2JNMC1HIlvy8Kcb6ivKZ2GoUSaZBGozeY14NM9k3Z3AEO3h2l-c_JF52WgKk70Q50ZrRMDOSX1OzoYrDx0H_pwlxuN9sQqs_GR4_BeH5YIezFTuo4jqV18jczQNA95AImcEkf2DPfVLCmNFlxPTBpM4auQKrmlYJWkJ1LWYQbD6lD29gMqWGP7IpEwGKI7EnvxTYnYeXZ6G5tmaTm0C1KHNKTAIvLgD0rOK25Fe-P11vata8pTgb2WZqkMhYuicZXS7ZDYbSS2JEAot5bgWn3xPLKYSl9L1d1fEB7no61JrNyOLAUxZVYScft0ewxnpSIWKybwdaEdsmNv28Re626ul4mZ6OPnJAA4pGvE0xA1Lf6SOBEq-v1qJIAe-ipsmwF4OnWUMW2NccmA7gHgGaydZgE7WMSfMe2NKdL54fJDK76I1BVUmHIfkhGUR2H5dwpGWcMxMZ4hemm29OsesW5QNUCooc7862oAmvi1JxX4A5oOflZOnObMDuuOlMALKOi6yHTsWqo-fi_TLYkqLOGdtII1h5SfVFPkJ5alZk_cfBLwOfJSNxVTIt34GUOtzOPRkgKeFBPXWOJWIIFueCMW-Qo9K0Fu_LY-AA1KIoTbg19WCPtJ86MaOQWL-f5YcOzGPWDirFZkmoZI5Iv4KrEZLzH2FIYoetebVX8qVJK6C19YHPUecZfawp3S3JF1e3u4HcZO2KUraJhioEaICsE8fmuFNu79E1IM0HDIbjyBXLeMUCHD8dCuNit0OR0t9yXq8JdZLcohB35hmOuIIA-4lnAuyZmRE0tD-E9EH6QA5cRFp_iOXM7hZ3L6A7pOth7fqv6aQp0i3Hble8VCJAAjTuAtnuGZzzbqJJBCXb-0SOebg8cw9KkWgAfeEVHBRDh_Cw8h2zosSqlzM4tVeZwBm00> . Strangely, I find it useful. I use it as a supplement to the inspector. I hope to be able to pack this tool, and a companion one for generating sequence diagrams based on the execution of a block given as parameter. I see these tools as exploratory tools, not as documentation tools. Best, Kasper,

8 14

Re: [Pharo-users] why is masses not found?
by Sean P. DeNigris Jan. 1, 2020

Jan. 1, 2020

Pharo Smalltalk Users mailing list wrote > when I call on the class side the method which > should reed the masses which are on the instanc side , the masses > cannnot be found. IntComputer class >> solution | computer ram | computer := self new. computer readRam: masses. ... In your code above, you are not actually "calling a class-side method" (which BTW in Smalltalk the term is "sending a message", an important philosophical distinction if you want to grok Smalltalk), but referring to a class-side instance variable named "masses". The clue to this would have been that when you tried to compile the method, a dialog came up telling you about the undeclared variable. You seem to have clicked through choosing to create a variable, which you can now see in the class-side class definition: IntComputer class instanceVariableNames: 'masses' Probably you forgot to add "computer" before "masses", like so: `computer readRam: computer masses.` For future exploration, there are some design smells in your code, but it seems like you're currently at the "get it to work" stage, so it seems premature to dive into them here. NB: It will be much easier to help you in the future, if you include both of the following in your questions: 1. the exact error 2. "steps to reproduce" IOW in this case, something like: "I'm seeing '#splitOn: was sent to nil' from IntComputer class>>#readRam:. To reproduce, do `IntComputer solution`" This way we don't have to go hunting for an entry point, which will stop many (busy) people from even trying! ----- Cheers, Sean -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html

2 1

Re: [Pharo-users] why is masses not found?
by Esteban Maringolo Dec. 31, 2019

Dec. 31, 2019

On Tue, Dec 31, 2019 at 11:29 AM Roelof Wobben via Pharo-users <pharo-users(a)lists.pharo.org> wrote: > > I solved it but I think with ugly code on the class side. > > solution > | computer | > computer := self new. > computer readRam: computer masses. > computer patchRam: 1 value: 12. > computer patchRam: 2 value: 2. > computer processData: computer ram. > computer at: 0 > > Is there a way I can make this more smalltalk. I don't know exactly why you mean by "more smalltalk", I don't know the problem you're solving, but you have a class side method that doesn't return anything, and the readRam: and processData: methods pass arguments that the receiver already have. So I'd do: solution | computer | computer := self new. computer readMasses; computer patchRam: 1 value: 12. computer patchRam: 2 value: 2. computer processRAMData. ^computer at: 0 "I don't know what this does".

1 0

Re: [Pharo-users] why is masses not found?
by Ben Coman Dec. 31, 2019

Dec. 31, 2019

Hi Roelof, I could file-in or look at your attached code to try to help, but its not clear what your question is or how to reproduce your scenario. You say... "when I call on the class side the method which should read the masses" which is a non-specific **description**. So I feel its extra work to try and decipher your question and perhaps I won't work it out and it would be wasted effort, which discourages me from trying to answer. Being more specific, something like... "when I call MyClass class>>myMethodXyz" would make feel like I have a chance at answering. Same for... "at the process method" - I see no method named #process so I can't guess what you question is. I've taken the time to provide this feedback to encourage you to improve your question to facilitate a better response. I recommend reading... http://www.catb.org/~esr/faqs/smart-questions.html (although the tone is a bit dark, there are some useful tidbits) cheers -ben P.S. Before your next (improved :^) restatement of your question, could you try an exercise... Slowly debug into the class-side call you are making, each step recording on paper on a new line the message sent, and on the same line the value of significant variables, to see if anything unexpected catches your attention. When the stepping is at a return statement ($^), select that statement and Inspect it, so you are sure of the value being returned. HTH. And btw, keep at it. The "process" of finding out why things don't work as expected is where you learn the most. On Tue, 31 Dec 2019 at 22:02, Roelof Wobben via Pharo-users < pharo-users(a)lists.pharo.org> wrote: > Hello, > > Im still trying to make part1 of day2 working at a way I can also test > things. > the tests are working but when I call on the class side the method which > should reed the masses which are on the instanc side , the masses > cannnot be found. > > So question 1 is why is masses not found. > > and question 2 is how can I use the changed array at the process method > so I can calculate the outcome. > > Regards, > > Roelof > >

1 0

why is masses not found?
by Roelof Wobben Dec. 31, 2019

Dec. 31, 2019

Hello, Im still trying to make part1 of day2 working at a way I can also test things. the tests are working but when I call on the class side the method which should reed the masses which are on the instanc side , the masses cannnot be found. So question 1 is why is masses not found. and question 2Â is how can I use the changed array at the process method so I can calculate the outcome. Regards, Roelof

2 5

Hi Community
by Pablo Navarro Dec. 30, 2019

Dec. 30, 2019

Hi everyone, my name's Pablo and I'm from Argentina. I'm taking my first steps in Pharo and created this tool (https://github.com/pablo1n7/Smallbook) to share with my colleagues and show them the power of Pharo. It's a simple library to create slide presentations and show them in a web browser. I used Zinc HTTP for the server, JS for the presentation controls and CSS for the styles. It's not 100% complete, I'm still working on it. I hope you find it useful and any suggestion is welcomed Best Regards, Pablo.

5 6

Re: [Pharo-users] can I write this without the three if then;s
by ponyatov Dec. 30, 2019

Dec. 30, 2019

What Smalltalk has for full-sized pattern matching? Is it possible to make in message-only syntax? -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html

1 0

Re: [Pharo-users] can I write this without the three if then;s
by Richard Sargent Dec. 30, 2019

Dec. 30, 2019

Pharo Smalltalk Users mailing list wrote > Hello, > > Im trying to solve a challenge from exercism whereÂ I have to > calculate the points somehow gets on a very simple darts board. > > I solved it like this : > > > scoreX: anInteger y: anInteger2 > Â Â Â | distance | > Â Â Â distance := (anInteger squared + anInteger2 squared) sqrt. > Â Â Â distance > 10 > Â Â Â Â Â Â ifTrue: [ ^ 0 ]. > Â Â Â distance > 5 > Â Â Â Â Â Â ifTrue: [ ^ 1 ]. > Â Â Â distance > 1 > Â Â Â Â Â Â ifTrue: [ ^ 5 ]. > Â Â Â ^ 10 > > > but now I use three if then and I think it's ugly code. > > Is there a way I can make it more the smalltalk way ? Roelof, this example is too simple to "really do it the Smalltalk way". In a more realistic scenario, you would have classes for each "rule" with corresponding differences in behaviour. In the above example, you could get away with a single class with two instance variables and configure three instances of it appropriately. In more complex scenarios, your start up code instantiates the various rules, with precedence determined by the order of the rule instances. Then when you need to determine which rule to apply, you use #detect:ifNone: to find the rule that applies with the #ifNone: block providing the fallback result. Sometimes, you work with classes themselves to determine which class to use, but I have described working with instances for the general concept. (After all, classes are instances.) Using rules with a #select: allows you to handle a scenario where multiple rules apply. A good example is rules to provide the default coverages for an auto insurance policy, where each possible coverage can have one or more rules to assess the many characteristics of the applicants and so determine the one rule that applies for each possible coverage. (And yes, it is reasonable that a possible coverage has no rule applicable, in which case the coverage is not included in the default offering.) As mentioned, you /could/ apply this to your scenario, as an exercise. You might be tempted to utilize an existing class with two instance variables. That would be a bad design practice, but reasonable for a /disposable/ experiment to quickly study how it works. Always (create and) use classes which truly reflect their purpose and have named properties which truly reflect the objects they hold. In your scenario, #distance and #score seem appropriate. > > Regards, > > Roelof -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html

1 0

Date offset in Glorp and RDBMS
by eftomi Dec. 29, 2019

Dec. 29, 2019

Dear all, Going through the remaining red tests in PharoADO + Glorp, I have a sort of a conceptual challenge. Some of the Glorp tests are checking the equality of dates written to and then returned from the database. Pharo regards the dates as not equal if their time offsets are different despite the fact that the date (in a narrow sense) is the same. For instance: "2019-12-29T00:00:00+01:00" is not equal to "2019-12-29T00:00:00+00:00" The challenge is that the ActiveX Data Objects (ADO) library that I'm using returnes the dates in Variants which don't have any information about the offset. The conversion from ADO variants to Pharo's Date is done in PharoCOM package. What would be the best approach to somehow ignore the missing offset or impute a proper value? Of course it's better to ignore a missing data than to impute a wrong value. How is this handled with other DB systems? Thanks, Tomaz -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html

3 4

Re: [Pharo-users] how to change data on real data but not on test data
by Sean P. DeNigris Dec. 28, 2019

Dec. 28, 2019

Pharo Smalltalk Users mailing list wrote > so to be clear. In the test are data given which not has to be changed. As > soon as you have to solve the real problem , some data needs to be > changed. It's difficult to give good design advice with such a partial picture of the domain, but two straightforward solutions might be: 1. self isDeploymentMode ifTrue: [ "change data" ] 2. or, self sanitizationStrategy: (NoSanitization | ProductionSanitization) ----- Cheers, Sean -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html

2 1