> > Nice! Almost as elegant as Ward's legendary > Symbol>>value: anObject > ^anObject perform: self Mickey!) I don't understand how does it help me. The method is called #perform:with: and it takes two arguments. Yes. But what if I need to emulate "x perform: y with: z" - there is three arguments How can I do this using perform? Yes, there is Behavior class that compile everything so non can help this method is good. But what about perform? Message class also require selector and what is selector for keyword messages? 2012/4/29 Jean-François LEFEVRE <jflefevre@gmail.com> > You probably want to do something like this : > > > | x y plu perf wi args | > x := 3. > y := 4. > plu := '+'. > perf := 'perform:withArguments:'. > args := Array new: 1. > args at: 1 put: y. > x perform: perf asSymbol withArguments: args > > You should look the class Message too. > (and all other classes and methods like Behavior, Class, Metaclass, Method > and Object) > > Jean-François > > > > 2012/4/29 Vitaly Kosenko <vitaly.kosenko@gmail.com> > >> Ok. perform: is working for arithmetic but what about perform: itself? >> | x y plu perf wi args | >> x := 3. >> y := 4. >> plu := '+'. >> perf := 'perform:'. >> wi := 'with:'. >> args := Array new: 3. >> args >> at: 1 put: plu asSymbol; >> at: 2 put: wi asSymbol; >> at: 3 put: y. >> x perform: perf asSymbol withArguments: args. >> >> This code tells me that there is wrong number of arguments in permforn: >> How can I fix it? >> >> >> 2012/4/29 vittly <vitaly.kosenko@gmail.com> >> >>> Mmm thnx for replie! I'll run this code and experemt with it >>> >>> 2012/4/29 Georg Heeg [via Smalltalk] <[hidden email]<http://user/SendEmail.jtp?type=node&node=4596244&i=0> >>> > >>> >>>> Please try to understand the following code: >>>> >>>> | a b c | >>>> >>>> a := 3. >>>> b := 4. >>>> c := '+'. >>>> ^a perform: c asSymbol with: b >>>> >>>> Georg Heeg eK, Dortmund und Köthen, HR Dortmund A 12812 >>>> Wallstraße 22, 06366 Köthen >>>> Tel. +49-3496-214328, Fax +49-3496-214712 >>>> >>>> >>>> -----Ursprüngliche Nachricht----- >>>> Von: [hidden email]<http://user/SendEmail.jtp?type=node&node=4596217&i=0> >>>> [mailto:[hidden email]<http://user/SendEmail.jtp?type=node&node=4596217&i=1>] >>>> Im Auftrag von vittly >>>> Gesendet: Sonntag, 29. April 2012 10:25 >>>> An: [hidden email]<http://user/SendEmail.jtp?type=node&node=4596217&i=2> >>>> Betreff: [Esug-list] metaprogramming in smalltalk >>>> >>>> Hi! Please could you help me understand smalltalk capabilities in >>>> metaprogramming? Q: could I construct arbitrary message by program? >>>> Create >>>> keywords from strings and than build sequence of them to make a >>>> message. Mm? >>>> Or may be store keywords in variables and then pass variables withing >>>> messages extracting stored keywords? >>>> Am I dreamer?) >>>> >>>> >>>> -- >>>> View this message in context: >>>> >>>> http://forum.world.st/metaprogramming-in-smalltalk-tp4595928p4595928.html >>>> Sent from the ESUG mailing list archive at Nabble.com. >>>> >>>> _______________________________________________ >>>> Esug-list mailing list >>>> [hidden email] <http://user/SendEmail.jtp?type=node&node=4596217&i=3> >>>> http://lists.esug.org/mailman/listinfo/esug-list_lists.esug.org >>>> >>>> >>>> >>>> _______________________________________________ >>>> Esug-list mailing list >>>> [hidden email] <http://user/SendEmail.jtp?type=node&node=4596217&i=4> >>>> http://lists.esug.org/mailman/listinfo/esug-list_lists.esug.org >>>> >>>> >>>> ------------------------------ >>>> If you reply to this email, your message will be added to the >>>> discussion below: >>>> >>>> http://forum.world.st/metaprogramming-in-smalltalk-tp4595928p4596217.html >>>> To unsubscribe from metaprogramming in smalltalk, click here. >>>> NAML<http://forum.world.st/template/NamlServlet.jtp?macro=macro_viewer&id=instant_html%21nabble%3Aemail.naml&base=nabble.naml.namespaces.BasicNamespace-nabble.view.web.template.NabbleNamespace-nabble.view.web.template.NodeNamespace&breadcrumbs=notify_subscribers%21nabble%3Aemail.naml-instant_emails%21nabble%3Aemail.naml-send_instant_email%21nabble%3Aemail.naml> >>>> >>> >>> >>> ------------------------------ >>> View this message in context: Re: metaprogramming in smalltalk<http://forum.world.st/metaprogramming-in-smalltalk-tp4595928p4596244.html> >>> >>> Sent from the ESUG mailing list archive<http://forum.world.st/ESUG-f1589038.html>at Nabble.com. >>> >>> _______________________________________________ >>> Esug-list mailing list >>> Esug-list@lists.esug.org >>> http://lists.esug.org/mailman/listinfo/esug-list_lists.esug.org >>> >>> >> >> _______________________________________________ >> Esug-list mailing list >> Esug-list@lists.esug.org >> http://lists.esug.org/mailman/listinfo/esug-list_lists.esug.org >> >> >

Hi Vitaly! try to think it like this: #perform:with: is a reflective operation to send messags to an object. Thus, if you are trying to send an object a message like: object perform: someSelector with: someArgument. - The receiver is object - the selector of the message is #perform:with: - the arguments of #perform:with: are someSelector and someArgument. Then, what you have to do is object perform: #perform:with: withArguments: { someSelector . someArgument } Because #perform: and #with: are not two different messages, they are two keywords of the same selector, in the same message. Then, you have to treat them together. Cheers, Guille 2012/4/29 Vitaly Kosenko <vitaly.kosenko@gmail.com> > Nice! Almost as elegant as Ward's legendary >> Symbol>>value: anObject >> ^anObject perform: self > > Mickey!) I don't understand how does it help me. > > The method is called #perform:with: and it takes two arguments. > > Yes. But what if I need to emulate "x perform: y with: z" - there is three > arguments > > How can I do this using perform? > > Yes, there is Behavior class that compile everything so non can help this > method is good. But what about perform? Message class also require selector > and what is selector for keyword messages? > > 2012/4/29 Jean-François LEFEVRE <jflefevre@gmail.com> > >> You probably want to do something like this : >> >> >> | x y plu perf wi args | >> x := 3. >> y := 4. >> plu := '+'. >> perf := 'perform:withArguments:'. >> args := Array new: 1. >> args at: 1 put: y. >> x perform: perf asSymbol withArguments: args >> >> You should look the class Message too. >> (and all other classes and methods like Behavior, Class, Metaclass, >> Method and Object) >> >> Jean-François >> >> >> >> 2012/4/29 Vitaly Kosenko <vitaly.kosenko@gmail.com> >> >>> Ok. perform: is working for arithmetic but what about perform: itself? >>> | x y plu perf wi args | >>> x := 3. >>> y := 4. >>> plu := '+'. >>> perf := 'perform:'. >>> wi := 'with:'. >>> args := Array new: 3. >>> args >>> at: 1 put: plu asSymbol; >>> at: 2 put: wi asSymbol; >>> at: 3 put: y. >>> x perform: perf asSymbol withArguments: args. >>> >>> This code tells me that there is wrong number of arguments in permforn: >>> How can I fix it? >>> >>> >>> 2012/4/29 vittly <vitaly.kosenko@gmail.com> >>> >>>> Mmm thnx for replie! I'll run this code and experemt with it >>>> >>>> 2012/4/29 Georg Heeg [via Smalltalk] <[hidden email]<http://user/SendEmail.jtp?type=node&node=4596244&i=0> >>>> > >>>> >>>>> Please try to understand the following code: >>>>> >>>>> | a b c | >>>>> >>>>> a := 3. >>>>> b := 4. >>>>> c := '+'. >>>>> ^a perform: c asSymbol with: b >>>>> >>>>> Georg Heeg eK, Dortmund und Köthen, HR Dortmund A 12812 >>>>> Wallstraße 22, 06366 Köthen >>>>> Tel. +49-3496-214328, Fax +49-3496-214712 >>>>> >>>>> >>>>> -----Ursprüngliche Nachricht----- >>>>> Von: [hidden email]<http://user/SendEmail.jtp?type=node&node=4596217&i=0> >>>>> [mailto:[hidden email]<http://user/SendEmail.jtp?type=node&node=4596217&i=1>] >>>>> Im Auftrag von vittly >>>>> Gesendet: Sonntag, 29. April 2012 10:25 >>>>> An: [hidden email]<http://user/SendEmail.jtp?type=node&node=4596217&i=2> >>>>> Betreff: [Esug-list] metaprogramming in smalltalk >>>>> >>>>> Hi! Please could you help me understand smalltalk capabilities in >>>>> metaprogramming? Q: could I construct arbitrary message by program? >>>>> Create >>>>> keywords from strings and than build sequence of them to make a >>>>> message. Mm? >>>>> Or may be store keywords in variables and then pass variables withing >>>>> messages extracting stored keywords? >>>>> Am I dreamer?) >>>>> >>>>> >>>>> -- >>>>> View this message in context: >>>>> >>>>> http://forum.world.st/metaprogramming-in-smalltalk-tp4595928p4595928.html >>>>> Sent from the ESUG mailing list archive at Nabble.com. >>>>> >>>>> _______________________________________________ >>>>> Esug-list mailing list >>>>> [hidden email] <http://user/SendEmail.jtp?type=node&node=4596217&i=3> >>>>> http://lists.esug.org/mailman/listinfo/esug-list_lists.esug.org >>>>> >>>>> >>>>> >>>>> _______________________________________________ >>>>> Esug-list mailing list >>>>> [hidden email] <http://user/SendEmail.jtp?type=node&node=4596217&i=4> >>>>> http://lists.esug.org/mailman/listinfo/esug-list_lists.esug.org >>>>> >>>>> >>>>> ------------------------------ >>>>> If you reply to this email, your message will be added to the >>>>> discussion below: >>>>> >>>>> http://forum.world.st/metaprogramming-in-smalltalk-tp4595928p4596217.html >>>>> To unsubscribe from metaprogramming in smalltalk, click here. >>>>> NAML<http://forum.world.st/template/NamlServlet.jtp?macro=macro_viewer&id=instant_html%21nabble%3Aemail.naml&base=nabble.naml.namespaces.BasicNamespace-nabble.view.web.template.NabbleNamespace-nabble.view.web.template.NodeNamespace&breadcrumbs=notify_subscribers%21nabble%3Aemail.naml-instant_emails%21nabble%3Aemail.naml-send_instant_email%21nabble%3Aemail.naml> >>>>> >>>> >>>> >>>> ------------------------------ >>>> View this message in context: Re: metaprogramming in smalltalk<http://forum.world.st/metaprogramming-in-smalltalk-tp4595928p4596244.html> >>>> >>>> Sent from the ESUG mailing list archive<http://forum.world.st/ESUG-f1589038.html>at Nabble.com. >>>> >>>> _______________________________________________ >>>> Esug-list mailing list >>>> Esug-list@lists.esug.org >>>> http://lists.esug.org/mailman/listinfo/esug-list_lists.esug.org >>>> >>>> >>> >>> _______________________________________________ >>> Esug-list mailing list >>> Esug-list@lists.esug.org >>> http://lists.esug.org/mailman/listinfo/esug-list_lists.esug.org >>> >>> >> > > _______________________________________________ > Esug-list mailing list > Esug-list@lists.esug.org > http://lists.esug.org/mailman/listinfo/esug-list_lists.esug.org > >

| x y plu perf wi sel args | x := 3. y := 4. plu := '+'. perf := 'perform:'. wi := 'with:'. sel := perf,wi. args := Array new: 2. args at: 1 put: plu asSymbol; at: 2 put: y. x perform: sel asSymbol withArguments: args. It works! Great! Thanks a lot. About Pharo examples book: I have red some chapters but the real understanding comes only in prectice) 2012/4/30 Guillermo Polito <guillermopolito@gmail.com> > Hi Vitaly! > > try to think it like this: #perform:with: is a reflective operation to > send messags to an object. Thus, if you are trying to send an object a > message like: > > object perform: someSelector with: someArgument. > > - The receiver is object > - the selector of the message is #perform:with: > - the arguments of #perform:with: are someSelector and someArgument. > > Then, what you have to do is > > object > perform: #perform:with: > withArguments: { someSelector . someArgument } > > Because #perform: and #with: are not two different messages, they are two > keywords of the same selector, in the same message. Then, you have to > treat them together. > > Cheers, > Guille > > > 2012/4/29 Vitaly Kosenko <vitaly.kosenko@gmail.com> > >> Nice! Almost as elegant as Ward's legendary >>> Symbol>>value: anObject >>> ^anObject perform: self >> >> Mickey!) I don't understand how does it help me. >> >> The method is called #perform:with: and it takes two arguments. >> >> Yes. But what if I need to emulate "x perform: y with: z" - there is >> three arguments >> >> How can I do this using perform? >> >> Yes, there is Behavior class that compile everything so non can help this >> method is good. But what about perform? Message class also require selector >> and what is selector for keyword messages? >> >> 2012/4/29 Jean-François LEFEVRE <jflefevre@gmail.com> >> >>> You probably want to do something like this : >>> >>> >>> | x y plu perf wi args | >>> x := 3. >>> y := 4. >>> plu := '+'. >>> perf := 'perform:withArguments:'. >>> args := Array new: 1. >>> args at: 1 put: y. >>> x perform: perf asSymbol withArguments: args >>> >>> You should look the class Message too. >>> (and all other classes and methods like Behavior, Class, Metaclass, >>> Method and Object) >>> >>> Jean-François >>> >>> >>> >>> 2012/4/29 Vitaly Kosenko <vitaly.kosenko@gmail.com> >>> >>>> Ok. perform: is working for arithmetic but what about perform: itself? >>>> | x y plu perf wi args | >>>> x := 3. >>>> y := 4. >>>> plu := '+'. >>>> perf := 'perform:'. >>>> wi := 'with:'. >>>> args := Array new: 3. >>>> args >>>> at: 1 put: plu asSymbol; >>>> at: 2 put: wi asSymbol; >>>> at: 3 put: y. >>>> x perform: perf asSymbol withArguments: args. >>>> >>>> This code tells me that there is wrong number of arguments in permforn: >>>> How can I fix it? >>>> >>>> >>>> 2012/4/29 vittly <vitaly.kosenko@gmail.com> >>>> >>>>> Mmm thnx for replie! I'll run this code and experemt with it >>>>> >>>>> 2012/4/29 Georg Heeg [via Smalltalk] <[hidden email]<http://user/SendEmail.jtp?type=node&node=4596244&i=0> >>>>> > >>>>> >>>>>> Please try to understand the following code: >>>>>> >>>>>> | a b c | >>>>>> >>>>>> a := 3. >>>>>> b := 4. >>>>>> c := '+'. >>>>>> ^a perform: c asSymbol with: b >>>>>> >>>>>> Georg Heeg eK, Dortmund und Köthen, HR Dortmund A 12812 >>>>>> Wallstraße 22, 06366 Köthen >>>>>> Tel. +49-3496-214328, Fax +49-3496-214712 >>>>>> >>>>>> >>>>>> -----Ursprüngliche Nachricht----- >>>>>> Von: [hidden email]<http://user/SendEmail.jtp?type=node&node=4596217&i=0> >>>>>> [mailto:[hidden email]<http://user/SendEmail.jtp?type=node&node=4596217&i=1>] >>>>>> Im Auftrag von vittly >>>>>> Gesendet: Sonntag, 29. April 2012 10:25 >>>>>> An: [hidden email]<http://user/SendEmail.jtp?type=node&node=4596217&i=2> >>>>>> Betreff: [Esug-list] metaprogramming in smalltalk >>>>>> >>>>>> Hi! Please could you help me understand smalltalk capabilities in >>>>>> metaprogramming? Q: could I construct arbitrary message by program? >>>>>> Create >>>>>> keywords from strings and than build sequence of them to make a >>>>>> message. Mm? >>>>>> Or may be store keywords in variables and then pass variables withing >>>>>> messages extracting stored keywords? >>>>>> Am I dreamer?) >>>>>> >>>>>> >>>>>> -- >>>>>> View this message in context: >>>>>> >>>>>> http://forum.world.st/metaprogramming-in-smalltalk-tp4595928p4595928.html >>>>>> Sent from the ESUG mailing list archive at Nabble.com. >>>>>> >>>>>> _______________________________________________ >>>>>> Esug-list mailing list >>>>>> [hidden email] <http://user/SendEmail.jtp?type=node&node=4596217&i=3> >>>>>> http://lists.esug.org/mailman/listinfo/esug-list_lists.esug.org >>>>>> >>>>>> >>>>>> >>>>>> _______________________________________________ >>>>>> Esug-list mailing list >>>>>> [hidden email] <http://user/SendEmail.jtp?type=node&node=4596217&i=4> >>>>>> http://lists.esug.org/mailman/listinfo/esug-list_lists.esug.org >>>>>> >>>>>> >>>>>> ------------------------------ >>>>>> If you reply to this email, your message will be added to the >>>>>> discussion below: >>>>>> >>>>>> http://forum.world.st/metaprogramming-in-smalltalk-tp4595928p4596217.html >>>>>> To unsubscribe from metaprogramming in smalltalk, click here. >>>>>> NAML<http://forum.world.st/template/NamlServlet.jtp?macro=macro_viewer&id=instant_html%21nabble%3Aemail.naml&base=nabble.naml.namespaces.BasicNamespace-nabble.view.web.template.NabbleNamespace-nabble.view.web.template.NodeNamespace&breadcrumbs=notify_subscribers%21nabble%3Aemail.naml-instant_emails%21nabble%3Aemail.naml-send_instant_email%21nabble%3Aemail.naml> >>>>>> >>>>> >>>>> >>>>> ------------------------------ >>>>> View this message in context: Re: metaprogramming in smalltalk<http://forum.world.st/metaprogramming-in-smalltalk-tp4595928p4596244.html> >>>>> >>>>> Sent from the ESUG mailing list archive<http://forum.world.st/ESUG-f1589038.html>at Nabble.com. >>>>> >>>>> _______________________________________________ >>>>> Esug-list mailing list >>>>> Esug-list@lists.esug.org >>>>> http://lists.esug.org/mailman/listinfo/esug-list_lists.esug.org >>>>> >>>>> >>>> >>>> _______________________________________________ >>>> Esug-list mailing list >>>> Esug-list@lists.esug.org >>>> http://lists.esug.org/mailman/listinfo/esug-list_lists.esug.org >>>> >>>> >>> >> >> _______________________________________________ >> Esug-list mailing list >> Esug-list@lists.esug.org >> http://lists.esug.org/mailman/listinfo/esug-list_lists.esug.org >> >> >