- Pharo-dev - lists.pharo.org

Re: [Pharo-project] Some bugs

by StÃ©phane Ducasse

We were thinking with marcus that using byte code to go back to sources code is broken by essence and that using an AST is the way to go. Now we would need a good AST-based interpreter to start with. > 2011/9/5 StÃ©phane Ducasse <stephane.ducasse(a)inria.fr>: >> BTW mike roberts is building a tool to be able to understand and fix the code range of the debugger hilighting. >> Probably your bug is also related to the closure introduction. >> >> Now the abstraction used is so low level that this is a pain and fragile. >> Ideally using an AST would be much better but this is for the future. >> >> Stef >> > > Stef, > If you are saying that implementation is not crystal clear, I can only > agree with you. > Eliot did avoid a full rewrite (I guess he took the shortest path to > make the available implementation work with closures), and this design > decision can be questioned indeed. > > But speaking of abstraction level by itself, I don't understand your sentence. > To me, the abstraction is at the correct level. > The Debugger has to map the low level execution machinery > (Context/program counter/CompiledMethod/byteCodes) to high level > specification visible to the user (source code). > The Debugger does so by mapping bytecodes to source ranges via AST, no > more, no less. > > In case of inlined blocks, there are more instructions on the bytecode > side than messages sent on the AST side, just to make the problem a > bit more complex, so maybe there are more intelligent way to address > the mapping problem (maybe you mean via an intermediate transformation > of AST), but you'll have to explain this a bit deeper. > > Nicolas > >> >> On Sep 5, 2011, at 9:07 AM, Andrea BrÃ¼hlmann wrote: >> >>> Hello Stef, >>> >>> I appreciate the work of the pharo community! We will continue reporting bugs and submit fixes that >>> we made. Of course I do not expect anyone to fix all reported bugs, but there are issues like 4694 >>> (debugger) where we really need your help. Other issues like the buggy code completion can be >>> workarounded by me by disabling code completion ;-) >>> >>> So thanks for the welcome and I am looking forward to having 4694 fixed! >>> >>> Andrea >>> >>> >>> >>> >>> StÃ©phane Ducasse schrieb: >>>> Thanks andrea >>>> Welcome to the pharo mailing-list and community. Now I think that this is important that inside netstyle you also consider that if pharo is important for you (which I imagine) that you should also contribute. Bug reporting is already a contribution. Pharo is an open-source software mainly supported by the free time of people, people that are often do not earning their money from their pharo work (I thank them for all that). I also understand that people can get frustrated by changes but what can we do? >>>> May be people can gather and check the fixes that are important to fix but we do not have the force to maintain. >>>> Imagine well that we have one engineer full time since 8 months. Stef >>>> On Aug 23, 2011, at 8:54 AM, Andrea BrÃ¼hlmann wrote: >>>>> Hello, >>>>> >>>>> I reported some bugs on the issue tracker and hope you can help me with them! >>>>> >>>>> >>>>> 4681: Accepting with the enter key does not work >>>>> http://code.google.com/p/pharo/issues/detail?id=4681 >>>>> >>>>> 4682: Code completion makes strange cursor placements and too many spaces >>>>> http://code.google.com/p/pharo/issues/detail?id=4682 >>>>> >>>>> 4683: Code completion breaks some search fields (errors during typing) >>>>> http://code.google.com/p/pharo/issues/detail?id=4683 >>>>> >>>>> 4684: Missing ctrl+w (methodNamesContainingIt:) >>>>> http://code.google.com/p/pharo/issues/detail?id=4684 >>>>> >>>>> 4685: Merge dialog: cannot resolve conflict with removed method >>>>> http://code.google.com/p/pharo/issues/detail?id=4685 >>>>> >>>>> 4686: Method category change creates no new version >>>>> http://code.google.com/p/pharo/issues/detail?id=4686 >>>>> >>>>> 4687: Errors during coding (MessageNotUnderstood: receiver of "morph" is nil) >>>>> http://code.google.com/p/pharo/issues/detail?id=4687 >>>>> >>>>> 4688: Progress bar disappears on image save >>>>> http://code.google.com/p/pharo/issues/detail?id=4688 >>>>> >>>>> 4689: MessageTally bug >>>>> http://code.google.com/p/pharo/issues/detail?id=4689 >>>>> >>>>> 4690: Progress bar position >>>>> http://code.google.com/p/pharo/issues/detail?id=4690 >>>>> >>>>> 4691: Bad line breaks in code until window is resized (because of bold text?) >>>>> http://code.google.com/p/pharo/issues/detail?id=4691 >>>>> >>>>> 4692: Drop downs should select the default entry (topmost) instead of a middle one >>>>> http://code.google.com/p/pharo/issues/detail?id=4692 >>>>> >>>>> 4693: Line breaks in tooltips are wrong >>>>> http://code.google.com/p/pharo/issues/detail?id=4693 >>>>> >>>>> 4694: Debugger: stepping over an error can not open a new debugger until I hit cmd+. >>>>> http://code.google.com/p/pharo/issues/detail?id=4694 >>>>> >>>>> 4695: Time asString prints nanos unrounded >>>>> http://code.google.com/p/pharo/issues/detail?id=4695 >>>>> >>>>> >>>>> -- >>>>> Andrea BrÃ¼hlmann >>>>> >>> >>> >>> -- >>> AB | ANDREA BRÃHLMANN Â· SOFTWARE ENGINEER >>> | NETSTYLE Â· TERRASSENWEG 18 Â· CH-3012 BERN >>> | TEL +41 31 356 42 54 Â· FAX +41 31 356 42 51 >>> | WWW.NETSTYLE.CH Â· A.BRUEHLMANN(a)NETSTYLE.CH >>> >> >> >> >

Sept. 5, 2011

Re: [Pharo-project] [Vm-dev] [VM-team] [ANN] VMMaker repository home is now http://source.squeak.org/VMMaker

by David T. Lewis

On Mon, Sep 05, 2011 at 09:38:02AM -0400, David T. Lewis wrote: > > The automated commit notices to the vm-dev list will now come from > source.squeak.org, and the commit notices from squeaksource.com have > been disabled. This is to permit files to be copied between > source.squeak.org/VMMaker and squeaksource.com/VMMaker without > duplicate commit notices. > Oops, the automated commit notices do not seem to be working yet, probably because of something I have configured wrong. I will manually bounce notices to the list until I get it sorted out (using commit notices from SqueakSource, which are still being directed to my email). Dave

Sept. 5, 2011

[Pharo-project] [VM-team] [ANN] VMMaker repository home is now http://source.squeak.org/VMMaker

by David T. Lewis

The VMMaker source repository is now located at: MCHttpRepository location: 'http://source.squeak.org/VMMaker' user: '' password: '' This is a mirror of the http://www.squeaksource.com/VMMaker repository, with all historical files, and with no change to policy. The intent of the move is to improve reliability and availability of the VMMaker repository for all project participants. The automated commit notices to the vm-dev list will now come from source.squeak.org, and the commit notices from squeaksource.com have been disabled. This is to permit files to be copied between source.squeak.org/VMMaker and squeaksource.com/VMMaker without duplicate commit notices. Commits to VMMaker should now be made to the new repository, and direct references to the VMMaker repository (e.g. ConfigurationOfVMMaker) should be updated to reflect the change. For Squeak and Pharo users who use VMMaker through Monticello or Metacello, there should be no immediate change. However, adding a repository for http://source.squeak.org/VMMaker is recommended at your earliest convenience. I wish to add my appreciation for SqueakSource, which serves as a valuable community resource and has for many years been the home of the VMMaker project. I further note that many plugins used by VMMaker are hosted on SqueakSource, and this will continue to be the case. Thanks also to Bert Freudenberg for setting up the new repository with a complete mirror copy of the VMMaker project. Dave

Sept. 5, 2011

[Pharo-project] #copyReplaceAll:with: vs. the schlemiel

by Camillo Bruni

I stumbled upon the horrible implementation of SequenceableCollection >> #copyReplaceAll:with: Not only was it horribly documented (only for strings) but also horribly inefficient nicely following the painters algorithm :). On to replacing this craftwork with a stream based solution I figured out that it breaks quite a few tests: Namely the #testCopyReplaceAllWith1Occurence test doesn't work with the following classes anymore: - LinkedList - Interval - SortedCollection - Symbol Now I think this test does't make much sense for SortedCollection/Intervals. SortedCollection enforces a certain order on the objects, meaning that replacing a slice of elements with something else yields a completely new intermediate collection. So unless the collection is first converted to an OrderedCollection I don't see much sense in supporting this method on SortedCollection. For Intervals there's a similar issue. Replacing elements in an Interval doesn't work (yetâ¦) so again, only an indirect OrderedCollection helps thereâ¦ On Symbol there's the problem of #streamContents which should use #species and an intermediate String to build up the Symbol. cami

Sept. 5, 2011

Re: [Pharo-project] Some bugs

by Nicolas Cellier

2011/9/5 Marcus Denker <marcus.denker(a)inria.fr>: > > On Sep 5, 2011, at 2:06 PM, Nicolas Cellier wrote: >> >> By the way, I would find it cool to have an optional byteCode view >> parallel to source code view and see the execution of byte codes, and >> why not, a view of Context stack frames. >> Also, the debugger might step message by message (AST-based) rather >> than byteCode by byteCode, is this what you mean by wrong abstraction >> level ? >> > With the wrong abstraction level: Why do we care about stepping bytecodes > at all? Why not only have an AST interpreter based debugger? > > Â Â Â Â Marcus > > OK, then I finally succeeded in decoding Marcus/Stef high level instructions into low level specifications. I translate here for those obscurantists speaking native gdb: you want step/jump instead of stepi/jumpi. But it would have been better to provide detailed explanations from the beginning for slow brained like me ;). Nonetheless, you still need to map execution machiney to source code because of initial program counter, and in case of AST-based stepping, the map must be bi-directional in order to execute multiple bytecodes sometimes required by a single instruction. Nicolas > > -- > Marcus Denker -- http://marcusdenker.de > > >

Sept. 5, 2011

Re: [Pharo-project] Zinc crashing image at start up

by Sven Van Caekenberghe

On 04 Sep 2011, at 22:35, Sven Van Caekenberghe wrote: > OK, thanks for the extra info. > I'll see what I can do tomorrow, after thinking about this a bit. > If I can't reproduce this, I can't debug it. I am really very confused and don't understand what is happening, but here is what I found out: Starting from the partial build artifact seaside3.[image|changes] #720 from http://jenkins.lukas-renggli.ch and using the VM http://www.mirandabanda.org/files/Cog/VM/VM.r2370/ on my Ubuntu 11.04 I finally could replicate a problem loading builder/scripts/seaside3-zinc.st. Now the hang (100% cpu, no crash or any log to be seen) only happens in two cases: running from the command line (as in the build script): ./coglinux/bin/squeak -nodisplay -nosound seaside3.image /home/sven/Smalltalk/builder/scripts/seaside3-zinc.st or doing a file in of this file using the File Browser in Pharo. Executing the same code manually (selecting it and performing a doit) works fine. Note to replicate this you have to use a specific version, as in Gofer new squeaksource: 'ZincHTTPComponents'; version: 'Zinc-HTTP-SvenVanCaekenberghe.191'; package: 'Zinc-Seaside'; load. And then starting the Seaside adapter in one go. On Mac OS X, I cannot reproduce this at all. The difference between the working version (188) and the failing ones (up until 191) is very small IMHO, that's what is so strange. So I decided to revert back by pushing down the connection management functionality of ZnMultiThreadedServer to a new subclass called ZnManagingMultiThreadedServer. Now the code difference between working and failing code is even smaller. Note also that the server is just started, it is not yet receiving any connections! Any help would be appreciated ;-) Lukas, I think you could try to rebuild the failing Seaside jobs. Sven

Sept. 5, 2011

Re: [Pharo-project] Some bugs

by Marcus Denker

On Sep 5, 2011, at 2:06 PM, Nicolas Cellier wrote: > > By the way, I would find it cool to have an optional byteCode view > parallel to source code view and see the execution of byte codes, and > why not, a view of Context stack frames. > Also, the debugger might step message by message (AST-based) rather > than byteCode by byteCode, is this what you mean by wrong abstraction > level ? > With the wrong abstraction level: Why do we care about stepping bytecodes at all? Why not only have an AST interpreter based debugger? Marcus -- Marcus Denker -- http://marcusdenker.de

Sept. 5, 2011

Re: [Pharo-project] Some bugs

by Nicolas Cellier

2011/9/5 Nicolas Cellier <nicolas.cellier.aka.nice(a)gmail.com>: > 2011/9/5 StÃ©phane Ducasse <stephane.ducasse(a)inria.fr>: >> BTW mike roberts is building a tool to be able to understand and fix the code range of the debugger hilighting. >> Probably your bug is also related to the closure introduction. >> >> Now the abstraction used is so low level that this is a pain and fragile. >> Ideally using an AST would be much better but this is for the future. >> >> Stef >> > > Stef, > If you are saying that implementation is not crystal clear, I can only > agree with you. > Eliot did avoid a full rewrite (I guess he took the shortest path to > make the available implementation work with closures), and this design > decision can be questioned indeed. > > But speaking of abstraction level by itself, I don't understand your sentence. > To me, the abstraction is at the correct level. > The Debugger has to map the low level execution machinery > (Context/program counter/CompiledMethod/byteCodes) to high level > specification visible to the user (source code). > The Debugger does so by mapping bytecodes to source ranges via AST, no > more, no less. > > In case of inlined blocks, there are more instructions on the bytecode > side than messages sent on the AST side, just to make the problem a > bit more complex, so maybe there are more intelligent way to address > the mapping problem (maybe you mean via an intermediate transformation > of AST), but you'll have to explain this a bit deeper. > > Nicolas > By the way, I would find it cool to have an optional byteCode view parallel to source code view and see the execution of byte codes, and why not, a view of Context stack frames. Also, the debugger might step message by message (AST-based) rather than byteCode by byteCode, is this what you mean by wrong abstraction level ? Nicolas >> >> On Sep 5, 2011, at 9:07 AM, Andrea BrÃ¼hlmann wrote: >> >>> Hello Stef, >>> >>> I appreciate the work of the pharo community! We will continue reporting bugs and submit fixes that >>> we made. Of course I do not expect anyone to fix all reported bugs, but there are issues like 4694 >>> (debugger) where we really need your help. Other issues like the buggy code completion can be >>> workarounded by me by disabling code completion ;-) >>> >>> So thanks for the welcome and I am looking forward to having 4694 fixed! >>> >>> Andrea >>> >>> >>> >>> >>> StÃ©phane Ducasse schrieb: >>>> Thanks andrea >>>> Welcome to the pharo mailing-list and community. Now I think that this is important that inside netstyle you also consider that if pharo is important for you (which I imagine) that you should also contribute. Bug reporting is already a contribution. Â Pharo is an open-source software mainly supported by the free time of people, people that are often do not earning their money from their pharo work (I thank them for all that). I also understand that people can get frustrated by changes but what can we do? >>>> May be people can gather and check the fixes that are important to fix but we do not have the force to maintain. >>>> Imagine well that we have one engineer full time since 8 months. Stef >>>> On Aug 23, 2011, at 8:54 AM, Andrea BrÃ¼hlmann wrote: >>>>> Hello, >>>>> >>>>> I reported some bugs on the issue tracker and hope you can help me with them! >>>>> >>>>> >>>>> 4681: Accepting with the enter key does not work >>>>> Â Â http://code.google.com/p/pharo/issues/detail?id=4681 >>>>> >>>>> 4682: Code completion makes strange cursor placements and too many spaces >>>>> Â Â http://code.google.com/p/pharo/issues/detail?id=4682 >>>>> >>>>> 4683: Code completion breaks some search fields (errors during typing) >>>>> Â Â http://code.google.com/p/pharo/issues/detail?id=4683 >>>>> >>>>> 4684: Missing ctrl+w (methodNamesContainingIt:) >>>>> Â Â http://code.google.com/p/pharo/issues/detail?id=4684 >>>>> >>>>> 4685: Merge dialog: cannot resolve conflict with removed method >>>>> Â Â http://code.google.com/p/pharo/issues/detail?id=4685 >>>>> >>>>> 4686: Method category change creates no new version >>>>> Â Â http://code.google.com/p/pharo/issues/detail?id=4686 >>>>> >>>>> 4687: Errors during coding (MessageNotUnderstood: receiver of "morph" is nil) >>>>> Â Â http://code.google.com/p/pharo/issues/detail?id=4687 >>>>> >>>>> 4688: Progress bar disappears on image save >>>>> Â Â http://code.google.com/p/pharo/issues/detail?id=4688 >>>>> >>>>> 4689: MessageTally bug >>>>> Â Â http://code.google.com/p/pharo/issues/detail?id=4689 >>>>> >>>>> 4690: Progress bar position >>>>> Â Â http://code.google.com/p/pharo/issues/detail?id=4690 >>>>> >>>>> 4691: Bad line breaks in code until window is resized (because of bold text?) >>>>> Â Â http://code.google.com/p/pharo/issues/detail?id=4691 >>>>> >>>>> 4692: Drop downs should select the default entry (topmost) instead of a middle one >>>>> Â Â http://code.google.com/p/pharo/issues/detail?id=4692 >>>>> >>>>> 4693: Line breaks in tooltips are wrong >>>>> Â Â http://code.google.com/p/pharo/issues/detail?id=4693 >>>>> >>>>> 4694: Debugger: stepping over an error can not open a new debugger until I hit cmd+. >>>>> Â Â http://code.google.com/p/pharo/issues/detail?id=4694 >>>>> >>>>> 4695: Time asString prints nanos unrounded >>>>> Â Â http://code.google.com/p/pharo/issues/detail?id=4695 >>>>> >>>>> >>>>> -- >>>>> Andrea BrÃ¼hlmann >>>>> >>> >>> >>> -- >>> AB Â Â | Â ANDREA BRÃHLMANN Â· SOFTWARE ENGINEER >>> Â Â Â | Â NETSTYLE Â· TERRASSENWEG 18 Â· CH-3012 BERN >>> Â Â Â | Â TEL Â +41 31 356 42 54 Â· FAX Â +41 31 356 42 51 >>> Â Â Â | Â WWW.NETSTYLE.CH Â· A.BRUEHLMANN(a)NETSTYLE.CH >>> >> >> >> >

Sept. 5, 2011

Re: [Pharo-project] Some bugs

by Nicolas Cellier

2011/9/5 StÃ©phane Ducasse <stephane.ducasse(a)inria.fr>: > BTW mike roberts is building a tool to be able to understand and fix the code range of the debugger hilighting. > Probably your bug is also related to the closure introduction. > > Now the abstraction used is so low level that this is a pain and fragile. > Ideally using an AST would be much better but this is for the future. > > Stef > Stef, If you are saying that implementation is not crystal clear, I can only agree with you. Eliot did avoid a full rewrite (I guess he took the shortest path to make the available implementation work with closures), and this design decision can be questioned indeed. But speaking of abstraction level by itself, I don't understand your sentence. To me, the abstraction is at the correct level. The Debugger has to map the low level execution machinery (Context/program counter/CompiledMethod/byteCodes) to high level specification visible to the user (source code). The Debugger does so by mapping bytecodes to source ranges via AST, no more, no less. In case of inlined blocks, there are more instructions on the bytecode side than messages sent on the AST side, just to make the problem a bit more complex, so maybe there are more intelligent way to address the mapping problem (maybe you mean via an intermediate transformation of AST), but you'll have to explain this a bit deeper. Nicolas > > On Sep 5, 2011, at 9:07 AM, Andrea BrÃ¼hlmann wrote: > >> Hello Stef, >> >> I appreciate the work of the pharo community! We will continue reporting bugs and submit fixes that >> we made. Of course I do not expect anyone to fix all reported bugs, but there are issues like 4694 >> (debugger) where we really need your help. Other issues like the buggy code completion can be >> workarounded by me by disabling code completion ;-) >> >> So thanks for the welcome and I am looking forward to having 4694 fixed! >> >> Andrea >> >> >> >> >> StÃ©phane Ducasse schrieb: >>> Thanks andrea >>> Welcome to the pharo mailing-list and community. Now I think that this is important that inside netstyle you also consider that if pharo is important for you (which I imagine) that you should also contribute. Bug reporting is already a contribution. Â Pharo is an open-source software mainly supported by the free time of people, people that are often do not earning their money from their pharo work (I thank them for all that). I also understand that people can get frustrated by changes but what can we do? >>> May be people can gather and check the fixes that are important to fix but we do not have the force to maintain. >>> Imagine well that we have one engineer full time since 8 months. Stef >>> On Aug 23, 2011, at 8:54 AM, Andrea BrÃ¼hlmann wrote: >>>> Hello, >>>> >>>> I reported some bugs on the issue tracker and hope you can help me with them! >>>> >>>> >>>> 4681: Accepting with the enter key does not work >>>> Â Â http://code.google.com/p/pharo/issues/detail?id=4681 >>>> >>>> 4682: Code completion makes strange cursor placements and too many spaces >>>> Â Â http://code.google.com/p/pharo/issues/detail?id=4682 >>>> >>>> 4683: Code completion breaks some search fields (errors during typing) >>>> Â Â http://code.google.com/p/pharo/issues/detail?id=4683 >>>> >>>> 4684: Missing ctrl+w (methodNamesContainingIt:) >>>> Â Â http://code.google.com/p/pharo/issues/detail?id=4684 >>>> >>>> 4685: Merge dialog: cannot resolve conflict with removed method >>>> Â Â http://code.google.com/p/pharo/issues/detail?id=4685 >>>> >>>> 4686: Method category change creates no new version >>>> Â Â http://code.google.com/p/pharo/issues/detail?id=4686 >>>> >>>> 4687: Errors during coding (MessageNotUnderstood: receiver of "morph" is nil) >>>> Â Â http://code.google.com/p/pharo/issues/detail?id=4687 >>>> >>>> 4688: Progress bar disappears on image save >>>> Â Â http://code.google.com/p/pharo/issues/detail?id=4688 >>>> >>>> 4689: MessageTally bug >>>> Â Â http://code.google.com/p/pharo/issues/detail?id=4689 >>>> >>>> 4690: Progress bar position >>>> Â Â http://code.google.com/p/pharo/issues/detail?id=4690 >>>> >>>> 4691: Bad line breaks in code until window is resized (because of bold text?) >>>> Â Â http://code.google.com/p/pharo/issues/detail?id=4691 >>>> >>>> 4692: Drop downs should select the default entry (topmost) instead of a middle one >>>> Â Â http://code.google.com/p/pharo/issues/detail?id=4692 >>>> >>>> 4693: Line breaks in tooltips are wrong >>>> Â Â http://code.google.com/p/pharo/issues/detail?id=4693 >>>> >>>> 4694: Debugger: stepping over an error can not open a new debugger until I hit cmd+. >>>> Â Â http://code.google.com/p/pharo/issues/detail?id=4694 >>>> >>>> 4695: Time asString prints nanos unrounded >>>> Â Â http://code.google.com/p/pharo/issues/detail?id=4695 >>>> >>>> >>>> -- >>>> Andrea BrÃ¼hlmann >>>> >> >> >> -- >> AB Â Â | Â ANDREA BRÃHLMANN Â· SOFTWARE ENGINEER >> Â Â Â | Â NETSTYLE Â· TERRASSENWEG 18 Â· CH-3012 BERN >> Â Â Â | Â TEL Â +41 31 356 42 54 Â· FAX Â +41 31 356 42 51 >> Â Â Â | Â WWW.NETSTYLE.CH Â· A.BRUEHLMANN(a)NETSTYLE.CH >> > > >

Sept. 5, 2011

Re: [Pharo-project] Towards better HTTP client usage

by Sven Van Caekenberghe

Johannes, On 05 Sep 2011, at 12:34, Johannes Rasche wrote: > Hi Sven, I'm eagerly looking forward. > > Is this an announcement about what you're actually doing, or is it open for experiments? Both I guess. > Is there already a repository I can load? Yes, just load the latest version of Zn (see http://zn.stfx.eu) > Johannes Thanks for your interest! Sven > Am 04.09.2011 um 20:22 schrieb Sven Van Caekenberghe: > >> Towards better HTTP client usage >> >> At the last Pharo Sprint in Lille (July 8th), StÃ©phane and I were at one point trying to remove some old HTTPSocket usage (which indirectly uses Zn) and replace it with direct and clean Zn usage. We hadn't much time left and didn't get very far. But I realized afterwards that although technically everything was there to write good HTTP client code, it was way too difficult (it required to much code on the user's behalf). >> >> Hence I decided to try write a new client that would support this usage much better and encourage better HTTP client usage in general. Another goal of this new client is to ultimately replace all other clients currently in Zn (these different client are creating some confusion among users). >> >> ZnNeoClient (a temporary name, to be renamed to ZnClient in the future) is a single object with a lot of (convenience) API to build, execute and process HTTP client requests. It is somewhat similar to Gofer like classes. It is also somewhat comparable to ZnHttpClient but it contains even more functionality. >> >> The new tests in ZnNeoClientTests show some of the ways the client can be used. In the current Zn version all ZnClient class functionality as well as all ZnHTTPSocketFacade (and thus HTTPSocket and thus the rest of the image) has already been reimplemented using ZnNeoClient. These are good examples to look at. >> >> At one point I plan to write some proper documentation, when the design settles down a bit, but here are some examples: >> >> The simplest possible usage: >> >> ZnNeoClient new get: 'http://zn.stxfx.eu/zn/small.html'. >> >> This is shorthand for: >> >> ZnNeoClient new >> url: 'http://zn.stxfx.eu/zn/small.html'; >> get. >> >> Which is actually shorthand for: >> >> ZnNeoClient new >> url: 'http://zn.stxfx.eu/zn/small.html'; >> get; >> contents. >> >> If you know upfront that you will do only one request, you can help conserve resources by doing: >> >> ZnNeoClient new >> beOneShot; >> get: 'http://zn.stxfx.eu/zn/small.html'. >> >> Connections are kept open whenever possible unless #beOneShot is chosen. Multiple requests (possibly to the same host) can be issued using the same client instance. At the end, #close should be send to the client, but garbage collection cleans up as well. >> >> Specifying URLs as strings can sometimes be tricky when special characters such as spaces are involved, for this ZnNeoClient has a whole URL and request construction API. Here is an example: >> >> ZnNeoClient new >> http; >> host: 'www.google.com'; >> addPath: 'search'; >> queryAt: 'q' put: 'Pharo Smalltalk'; >> get. >> >> There is also API for specifying headers, forms, multipart uploads and so on. See the unit tests, the ZnClient class side as well as the ZnHTTPSocketFacade for examples. >> >> The result of an HTTP request is an HTTP response, modelled by ZnResponse. Hence, you can ask a client for the last #response, #entity, #contents or test for #isSuccess. >> >> Which brings us to the problem that it is not easy to properly set up and handle the various things that can go wrong. It is here that ZnNeoClient aims to make a big contribution. >> >> Assume the following example: at some URL there is a list of numbers as lines in a text file that we want to download and use. Let's start simple: >> >> ^ ZnNeoClient new >> get: 'http://www.example.com/numbers.txt'. >> >> When all is well, this will return the text file as string. Let's add parsing: >> >> ^ ZnNeoClient new >> contentReader: [ :entity | >> (entity contents lines do: [ :each | >> Integer readFrom: each ifFail: [ nil ] ]) >> select: [ :each | each notNil ] ]; >> get: 'http://www.example.com/numbers.txt'. >> >> This will make sure we get a (possibly empty) list of numbers. The problem is, when number.txt is not found by the server, we don't deal properly with that situation. We can fix that: >> >> ^ ZnNeoClient new >> enforceHttpSuccess: true; >> contentReader: [ :entity | >> (entity contents lines do: [ :each | >> Integer readFrom: each ifFail: [ nil ] ]) >> select: [ :each | each notNil ] ]; >> get: 'http://www.example.com/numbers.txt'. >> >> Now, a non-success code will throw an error. We should also make sure that we do get a text/plain document back, and we want a uniform error handler reaction: >> >> ^ ZnNeoClient new >> enforceHttpSuccess: true; >> enforceAcceptContentType: true; >> accept: ZnMimeType textPlain; >> contentReader: [ :entity | >> (entity contents lines do: [ :each | >> Integer readFrom: each ifFail: [ nil ] ]) >> select: [ :each | each notNil ] ]; >> ifFail: [ :exception | >> self log: exception printString, ' while fetching numbers'. >> ^ #() ]; >> get: 'http://www.example.com/numbers.txt'. >> >> The failBlock will be execute on any exception, including ZnHttpUnsuccessful and ZnUnexpectedContentType. >> >> What about unreliable networking in general: we need a timeout, but better still, we could retry the request once or twice to cover for (possibly transient) networking/server problems. >> >> ^ ZnNeoClient new >> timeout: 15; >> numberOfRetries: 1; >> retryDelay: 2; >> enforceHttpSuccess: true; >> enforceAcceptContentType: true; >> accept: ZnMimeType textPlain; >> contentReader: [ :entity | >> (entity contents lines do: [ :each | >> Integer readFrom: each ifFail: [ nil ] ]) >> select: [ :each | each notNil ] ]; >> ifFail: [ :exception | >> self log: exception printString, ' while fetching numbers'. >> ^ #() ]; >> get: 'http://www.example.com/numbers.txt'. >> >> If anything goes wrong, there will be one retry after a delay of 2 seconds. >> >> Although there are sensible defaults for all options, it will probably make sense to group the options, like this: >> >> ^ ZnNeoClient new >> systemPolicy; >> accept: ZnMimeType textPlain; >> contentReader: [ :entity | >> (entity contents lines do: [ :each | >> Integer readFrom: each ifFail: [ nil ] ]) >> select: [ :each | each notNil ] ]; >> ifFail: [ :exception | >> self log: exception printString, ' while fetching numbers'. >> ^ #() ]; >> get: 'http://www.example.com/numbers.txt'. >> >> Finding the proper defaults and policies will take some trial and error. Another strategy is factory method like ZnClient class>>#client or ZnHTTPSocketFacade class>>#client. >> >> Here is another real-world example, invoking a REST service that returns JSON (you need the JSJsonParser class that comes with Seaside): >> >> ^ ZnNeoClient new >> systemPolicy; >> beOneShot; >> url: 'http://easy.t3-platform.net/rest/geo-ip'; >> queryAt: 'address' put: '81.83.7.35'; >> accept: ZnMimeType applicationJson; >> contentReader: [ :entity | >> (JSJsonParser parse: entity contents) at: #country ]; >> ifFail: [ nil ]; >> get. >> >> Or as a utility method: >> >> XYZUtils class>>#countryForIpAddress: ipAddressString ifFail: failBlock >> ^ ZnNeoClient new >> systemPolicy; >> beOneShot; >> url: 'http://easy.t3-platform.net/rest/geo-ip'; >> queryAt: 'address' put: ipAddressString; >> accept: ZnMimeType applicationJson; >> contentReader: [ :entity | >> (JSJsonParser parse: entity contents) at: #country ]; >> ifFail: failBlock; >> get >> >> That's it for now. There is still some implementation and testing work to be done. As always, all feedback is welcome. >> >> Sven

Sept. 5, 2011