October 2010 - Pharo-users - lists.pharo.org

Simple OO smaltalk question

by Tony Giaccone

I'm new to Smalltalk and come from the java world and am looking for a bit of help on how something should be implemented. Assume I have a Person class and that there are three subclasses of that class Admin, Teacher, Student. I also have a class called UserManager I want to implement a method on UserManger>> class firstPageForUser: user This method looks at the class of the user and returns an initial page for each user after log in. I have this method implmented: Person>>class firstPageForUser ^nil Now on the UserManager clas>> firstPageForUser: user (user isKindOf: Person ) ifTrue: [returnPage := ( (user class) firstPageForUser) ]. Which as I'm sure most of you realize doesn't work. I'm not sure how to structure the call so that the right message gets sent to the class. My understanding is that even though the subclasses don't implement this method yet, that the method should be passed up the class tree till it finds the method in Person. However, I also know that the syntax for the method I've written isn't correct. What I want to do is make the call on the class for each subclass. I could do the same thing this way, right, but this seems more verbose and ugly then it has to be. (user isKindOf: RSPerson ) ifTrue: [returnPage := (RSPerson firstPageForUserClass) ]. (user isKindOf: RSAdmin ) ifTrue: [returnPage := (RSAdmin firstPageForUserClass) ]. (user isKindOf: RSTeacher ) ifTrue: [returnPage := (RSTeacher firstPageForUserClass) ]. (user isKindOf: RSStudent ) ifTrue: [returnPage := (RSStudent firstPageForUserClass) ]. ^returnPage

Oct. 10, 2010

Re: [Pharo-users] [Pharo-project] could not search contents at http://book.pharo-project.org

by Tudor Girba

Hi, Unfortunately, I cannot help much at this moment. The problem is due to a bug in Pier that crashes when there is a strange character in one of the pages. I believe this was fixed at some point, but I am not sure. Someone would have to update the Pier image. Cheers, Doru On 10 Oct 2010, at 11:53, Mariano Martinez Peck wrote: > Thanks! I can reproduce. > > Doru can you help us? > > Thanks > > Mariano > > On Thu, Oct 7, 2010 at 10:40 PM, Bernardo Ezequiel Contreras <vonbecmann(a)gmail.com> wrote: > Hi All, > > Description: > Could not search contents at http://book.pharo-project.org. > I would like to search some expression in the contents of the book. > > Steps to reproduce: > * goto to http://book.pharo-project.org > * click on main image > * add any string on search contents and press Enter > Actual Result: > Seaside Walkback > > Error: subscript is out of bounds: 8218 > > Expected Result: > a list of results that matches your input string > > > Thanks, > > > _______________________________________________ > Pharo-users mailing list > Pharo-users(a)lists.gforge.inria.fr > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-users > > > _______________________________________________ > Pharo-project mailing list > Pharo-project(a)lists.gforge.inria.fr > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project -- www.tudorgirba.com "In a world where everything is moving ever faster, one might have better chances to win by moving slower."

Oct. 10, 2010

Re: [Pharo-users] could not search contents at http://book.pharo-project.org

by Mariano Martinez Peck

Thanks! I can reproduce. Doru can you help us? Thanks Mariano On Thu, Oct 7, 2010 at 10:40 PM, Bernardo Ezequiel Contreras < vonbecmann(a)gmail.com> wrote: > Hi All, > > Description: > Could not search contents at http://book.pharo-project.org. > I would like to search some expression in the contents of the book. > > Steps to reproduce: > * goto to http://book.pharo-project.org > * click on main image > * add any string on search contents and press Enter > Actual Result: > Seaside Walkback Error: subscript is out of bounds: 8218Expected Result: > a list of results that matches your input string > > > Thanks, > > > _______________________________________________ > Pharo-users mailing list > Pharo-users(a)lists.gforge.inria.fr > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-users > >

Oct. 10, 2010

Re: [Pharo-users] Consuming delimiters in PetitParser

by HernÃ¡n Morales Durand

Hi Lukas, Yes, the simpler method worked fine, I was confused by the fact that after typing the first digit in the #digit parser (it could be many digits but no alphabetical characters in that part) the sticky evaluator tolds me "punctuation expected". For now I just need to parse one identifier. Thanks! 2010/10/8 Lukas Renggli <renggli(a)gmail.com>: > Hi HernÃ¡n, > > I am not really sure what you want to express with the following parser? > > Â Â ( #digit asParser plus flatten plusLazy: $| asParser ) > > Having multiple quantifications (#optional, #plus, #plusLazy:, > #plusGreedy:, #star, #starLazy:, #plusGreedy:, #times:, #min:, > #min:max:) in a row does not really make sense and seems likely a bug. > In your example the #plusLazy: will only be able to consume the > receiver once. As you can read in the method comment of #plusLazy: the > argument is not consumed, thus whatever follows will have to consume > it. > > If you want to accept multiple numbers like in > > Â Â >gi|123|456|789|abc > > then you should likely use #separatedBy: like in > > Â p := ( $> asParser , 'gi' asParser , $| asParser , > Â Â Â Â ( #digit asParser plus flatten separatedBy: $| asParser ) , > Â Â Â Â ($| asParser) , > Â Â Â Â ( (#letter asParser / #digit asParser / #space asParser / > #punctuation asParser ) asParser plus flatten ) ) end. > > If you just want one number then the simpler > > Â p := ( $> asParser , 'gi' asParser , $| asParser , > Â Â Â Â ( #digit asParser plus flatten ) , > Â Â Â Â ($| asParser) , > Â Â Â Â ( (#letter asParser / #digit asParser / #space asParser / > #punctuation asParser ) asParser plus flatten ) ) end. > > will do. > > Let us know if this solves your problem. > > Lukas > > > On 8 October 2010 21:29, HernÃ¡n Morales Durand <hernan.morales(a)gmail.com> wrote: >> Hi all, >> >> I'm writing a parser like the following >> >> ( $> asParser , 'gi' asParser , $| asParser , >> Â ( #digit asParser plus flatten plusLazy: $| asParser ) , >> Â Â Â Â ( (#letter asParser / #digit asParser / #space asParser / >> #punctuation asParser ) asParser plus flatten ) ) end >> >> In the attachment you will see the my sample input and the parsing >> result collection in which the last element is "|abc", but I want the >> #plusLazy: (or #plusGreedy: ?) to consume the $| delimiter so it >> results in >> >> #($> 'gi' $| #('648') $| 'abc') >> >> any suggestions? >> >> Cheers, >> >> -- >> HernÃ¡n Morales >> Information Technology Manager, >> Institute of Veterinary Genetics. >> National Scientific and Technical Research Council (CONICET). >> La Plata (1900), Buenos Aires, Argentina. >> Telephone: +54 (0221) 421-1799. >> Internal: 422 >> Fax: 425-7980 or 421-1799. >> >> _______________________________________________ >> Pharo-users mailing list >> Pharo-users(a)lists.gforge.inria.fr >> http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-users >> >> > > > > -- > Lukas Renggli > www.lukas-renggli.ch > > _______________________________________________ > Pharo-users mailing list > Pharo-users(a)lists.gforge.inria.fr > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-users > -- HernÃ¡n Morales Information Technology Manager, Institute of Veterinary Genetics. National Scientific and Technical Research Council (CONICET). La Plata (1900), Buenos Aires, Argentina. Telephone: +54 (0221) 421-1799. Internal: 422 Fax: 425-7980 or 421-1799.

Oct. 8, 2010

Re: [Pharo-users] Consuming delimiters in PetitParser

by Lukas Renggli

Hi HernÃ¡n, I am not really sure what you want to express with the following parser? ( #digit asParser plus flatten plusLazy: $| asParser ) Having multiple quantifications (#optional, #plus, #plusLazy:, #plusGreedy:, #star, #starLazy:, #plusGreedy:, #times:, #min:, #min:max:) in a row does not really make sense and seems likely a bug. In your example the #plusLazy: will only be able to consume the receiver once. As you can read in the method comment of #plusLazy: the argument is not consumed, thus whatever follows will have to consume it. If you want to accept multiple numbers like in >gi|123|456|789|abc then you should likely use #separatedBy: like in p := ( $> asParser , 'gi' asParser , $| asParser , ( #digit asParser plus flatten separatedBy: $| asParser ) , ($| asParser) , ( (#letter asParser / #digit asParser / #space asParser / #punctuation asParser ) asParser plus flatten ) ) end. If you just want one number then the simpler p := ( $> asParser , 'gi' asParser , $| asParser , ( #digit asParser plus flatten ) , ($| asParser) , ( (#letter asParser / #digit asParser / #space asParser / #punctuation asParser ) asParser plus flatten ) ) end. will do. Let us know if this solves your problem. Lukas On 8 October 2010 21:29, HernÃ¡n Morales Durand <hernan.morales(a)gmail.com> wrote: > Hi all, > > I'm writing a parser like the following > > ( $> asParser , 'gi' asParser , $| asParser , > Â ( #digit asParser plus flatten plusLazy: $| asParser ) , > Â Â Â Â ( (#letter asParser / #digit asParser / #space asParser / > #punctuation asParser ) asParser plus flatten ) ) end > > In the attachment you will see the my sample input and the parsing > result collection in which the last element is "|abc", but I want the > #plusLazy: (or #plusGreedy: ?) to consume the $| delimiter so it > results in > > #($> 'gi' $| #('648') $| 'abc') > > any suggestions? > > Cheers, > > -- > HernÃ¡n Morales > Information Technology Manager, > Institute of Veterinary Genetics. > National Scientific and Technical Research Council (CONICET). > La Plata (1900), Buenos Aires, Argentina. > Telephone: +54 (0221) 421-1799. > Internal: 422 > Fax: 425-7980 or 421-1799. > > _______________________________________________ > Pharo-users mailing list > Pharo-users(a)lists.gforge.inria.fr > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-users > > -- Lukas Renggli www.lukas-renggli.ch

Oct. 8, 2010

Consuming delimiters in PetitParser

by HernÃ¡n Morales Durand

Hi all, I'm writing a parser like the following ( $> asParser , 'gi' asParser , $| asParser , ( #digit asParser plus flatten plusLazy: $| asParser ) , ( (#letter asParser / #digit asParser / #space asParser / #punctuation asParser ) asParser plus flatten ) ) end In the attachment you will see the my sample input and the parsing result collection in which the last element is "|abc", but I want the #plusLazy: (or #plusGreedy: ?) to consume the $| delimiter so it results in #($> 'gi' $| #('648') $| 'abc') any suggestions? Cheers, -- HernÃ¡n Morales Information Technology Manager, Institute of Veterinary Genetics. National Scientific and Technical Research Council (CONICET). La Plata (1900), Buenos Aires, Argentina. Telephone: +54 (0221) 421-1799. Internal: 422 Fax: 425-7980 or 421-1799.

Oct. 8, 2010

Re: [Pharo-users] Hard crash when teaching

by Johan Fabry

So I was a bit annoyed about this behavior, because I still think it is a cool demo to show in class. So I had a poke around the system (Thanks Igor for pointing me in the right direction). What happens is that ImageMorph>>image: does at some point super extent: 2 * self borderWidth + image extent. where self borderWidth is an int. Now wait a minute, what does it mean, conceptually to sum an int with a point? I have no idea. So what are we doing here? Computing the extent considering the extra border size we have. So what we want to do is sum 2 points, now that does makes sense. super extent: (2 * self borderWidth) asPoint + image extent. With this fix, I can turn of coercion for Integers without any problem, fixing the original issue. Plus the behavior of ImageMorph>>image: is the same, as far as I can tell. Bonus: conceptually cleaner, more robust system, and the ability to do funky demos in class. See, I can do brain surgery, just not at the same time as teaching :-) (Marcus: this fix attached to the bug report, even though it is closed, just in case you consider it worthwhile ...) On 08 Oct 2010, at 09:07, StÃ©phane Ducasse wrote: >> It depends on when you want to use that particular brain later to do real work or not ... :-P > > ;D > _______________________________________________ > Pharo-users mailing list > Pharo-users(a)lists.gforge.inria.fr > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-users -- Johan Fabry jfabry(a)dcc.uchile.cl - http://dcc.uchile.cl/~jfabry PLEIAD Lab - Computer Science Department (DCC) - University of Chile

Oct. 8, 2010

Re: [Pharo-users] Hard crash when teaching

by StÃ©phane Ducasse

> It depends on when you want to use that particular brain later to do real work or not ... :-P ;D

Oct. 8, 2010

Re: [Pharo-users] Hard crash when teaching

by Johan Fabry

It depends on when you want to use that particular brain later to do real work or not ... :-P On 08 Oct 2010, at 02:54, StÃ©phane Ducasse wrote: > this is not beacuse self surgery is good when you cut your nails the morning in your bathroom > that operating your brain is not a stupid idea. > > Stef > >> Always fun when you want to show the students that everything can be changed in Smalltalk ... >> Inclusive the behavior of Integer>>+ >> Inclusive when the current behavior does strange things with the second argument when it is not a number (instead of simply throwing an error), e.g what happens in 1 + 'foo' >> Inclusive when you are debugging said expression. >> >> Apparantly that was too much to ask :-( Hard crash of the image :-( :-( >> >> Reported as issue http://code.google.com/p/pharo/issues/detail?id=3072 >> >> -- >> Johan Fabry >> jfabry(a)dcc.uchile.cl - http://dcc.uchile.cl/~jfabry >> PLEIAD Lab - Computer Science Department (DCC) - University of Chile >> >> >> >> >> _______________________________________________ >> Pharo-users mailing list >> Pharo-users(a)lists.gforge.inria.fr >> http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-users > > > _______________________________________________ > Pharo-users mailing list > Pharo-users(a)lists.gforge.inria.fr > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-users -- Johan Fabry jfabry(a)dcc.uchile.cl - http://dcc.uchile.cl/~jfabry PLEIAD Lab - Computer Science Department (DCC) - University of Chile

Oct. 8, 2010

Re: [Pharo-users] Hard crash when teaching

by StÃ©phane Ducasse

this is not beacuse self surgery is good when you cut your nails the morning in your bathroom that operating your brain is not a stupid idea. Stef > Always fun when you want to show the students that everything can be changed in Smalltalk ... > Inclusive the behavior of Integer>>+ > Inclusive when the current behavior does strange things with the second argument when it is not a number (instead of simply throwing an error), e.g what happens in 1 + 'foo' > Inclusive when you are debugging said expression. > > Apparantly that was too much to ask :-( Hard crash of the image :-( :-( > > Reported as issue http://code.google.com/p/pharo/issues/detail?id=3072 > > -- > Johan Fabry > jfabry(a)dcc.uchile.cl - http://dcc.uchile.cl/~jfabry > PLEIAD Lab - Computer Science Department (DCC) - University of Chile > > > > > _______________________________________________ > Pharo-users mailing list > Pharo-users(a)lists.gforge.inria.fr > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-users

Oct. 8, 2010