February 2016 - Pharo-dev - lists.pharo.org

[bloc] when saving bloc and relaunching I get

by stepharo

Feb. 26, 2016

Re: [Pharo-dev] Setting the font for a spec button

by Alexandre Bergel

Impressive! Alexandre > On Feb 26, 2016, at 5:45 PM, Stephan Eggermont <stephan(a)stack.nl> wrote: > > Makes it possible to use icon fonts > > Stephan > <Screenshot from 2016-02-26 17-43-19.png> -- _,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;: Alexandre Bergel http://www.bergel.eu ^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;.

Feb. 26, 2016

Re: [Pharo-dev] Run time checking with design by contract assertions

by Alain Rastoul

On 25/02/2016 23:48, Alain Rastoul wrote: @Stef, Alexandre, Damien, Nicolai, Stephan, Thank you for the discussions, pointing me errors and interesting link. I understood that the concept and/or it's implementation seems a bit obscure, partly because of the syntax I've chosen for pragmas. I will conform to some naming standards : #invariant/#pre/#post/on: will be clearer than #required/#ensured/appliedTo:. <contract: #invariant> ... <contract: #pre on: #aMethod> ... <contract: #pre on: #( #aMethod1 ... #aMethodn)> ... idem post: <contract: #post on: #aMethod> ... <contract: #post on: #( #aMethod1 ... #aMethodn)> ... I also note the suggestion of Damien (putting the pragma contracts in the methods) but I am not truly convinced and it would imply some rework, so I will not do that now - perhaps after a try. examples fooContract1 <contract: #invariant> ^ myState notNil. fooContract2 <contract: #post on: #foo> ... postAdd: anObject <contract: #post on: #(add: #addLast:)> ^ self includes: anObject etc. -- Alain

Feb. 26, 2016

Re: [Pharo-dev] Recursion inside #doesNotUnderstand: method. Why?

by Eliot Miranda

> On Feb 26, 2016, at 9:12 AM, Denis Kudriashov <dionisiydk(a)gmail.com> wrote: > > > 2016-02-25 18:24 GMT+01:00 Eliot Miranda <eliot.miranda(a)gmail.com>: >> It's so that when a doesNotUnderstand: occurs and one implements the method in the debugger one can proceed. The sentTo: at the end will now invoke the newly defined method and one can continue programming. > > But as I said I make experiment. And in Pharo this recursion is not needed to implement unknown messages in Debugger. But for case of Vincent it is needed Which implies that the debugger is doing something unnecessary. Instead of creating an activation of the newly defined message it could simply proceed? _,,,^..^,,,_ (phone)

Feb. 26, 2016

Re: [Pharo-dev] Run time checking with design by contract assertions

by Alain Rastoul

On 26/02/2016 16:36, Damien Cassou wrote: > Alexandre Bergel <alexandre.bergel(a)me.com> writes: > >> I still do not understand. I would imagine something like: >> >> foo >> <precondition: #invariant> >> <postcondition: #invariant> >> self bar > Hi Damien, Sorry for seeming pedantic but the concept is precise : when you express an invariant it must be true for all code of your class. (and they are several invariants for one class of course) 'Invariants' are conditions that do not change (hence the name) they are about object state, they are not post or pre conditions they are always true, in each methods, before and after if you specify in which methods they are true, it means they could be false in others and then they are not invariants by defintion ... > I have the same feeling. It looks strange to me that the precondition > itself decides where it applies. I have the impression that each method > should list its preconditions. > That said, I think your example would be: foo <precondition: myFooPrecondition> <postcondition: myFooPostcondition> or something like: foo <precondition: myFooPrecondition1, myFooPrecondition2 etc...> <postcondition: myFooPostcondition1, myFooPostcondition2 etc...> you would say in each method what check applies. That could be possible and the result would be the same IMHO a bit less flexible, but another option. Q: where would you define the invariants ? a method that is never call and is tagged ? myFooInvariant1 <invariant> -- Alain

Feb. 26, 2016

Re: [Pharo-dev] Recursion inside #doesNotUnderstand: method. Why?

by Denis Kudriashov

2016-02-25 18:24 GMT+01:00 Eliot Miranda <eliot.miranda(a)gmail.com>: > It's so that when a doesNotUnderstand: occurs and one implements the > method in the debugger one can proceed. The sentTo: at the end will now > invoke the newly defined method and one can continue programming. But as I said I make experiment. And in Pharo this recursion is not needed to implement unknown messages in Debugger. But for case of Vincent it is needed

Feb. 26, 2016

Re: [Pharo-dev] Setting the font for a spec button

by Sven Van Caekenberghe

Cool ! > On 26 Feb 2016, at 17:45, Stephan Eggermont <stephan(a)stack.nl> wrote: > > Makes it possible to use icon fonts > > Stephan > <Screenshot from 2016-02-26 17-43-19.png>

Feb. 26, 2016

Re: [Pharo-dev] Run time checking with design by contract assertions

by Alain Rastoul

On 26/02/2016 16:37, Alexandre Bergel wrote: ... >> With Pharo you cannot, if you assert or throw an error in a sensible place, you are likely to hang your image or to go for multiple errors poping everywhere since you will break the state of an important object. > > I do not think so. It is like putting a "self haltâ (or âHalt nowâ). It is all done using exceptions. > Yes, that's the point: they are lots of places where you simply cannot put self halt (timers, background processes - though in this case it works... debugger magic :), window resizing, mouse events ) >> Another thing is that with dbc paradigm (assertions about your code), there is no 'one invariant' but lots of, you will not be able to express them in a single method, even if you could it would be hundreds lines and you would have to copy them in all methods you will want to check. >> The complete horror to maintain when you change your code. > > I would not be that pessimistic. > Even if you write dedicated check methods to avoid pollute your code, you will have to call all the logic of your controls in each method, and decide for each one what checks are applicable or not. Thinking about object state checks (invariants), I cannot imagine I'll have to add a: 'self checkThatxxx' in all the methods of my class... ... > > Sure, you can imagine a solution using pragmas, but sincerely, I do not think it will be more flexible than using #assert:. Again, Javaâs assertions are very similar to what we have now. However, I am pretty convinced there are great opportunities on writing assertions. It is really hard to write them, which is why not many are doing so. Thinking again about java asserts, they are more powerful framework who do not use assert but comments which is like using pragmas. http://www.javaworld.com/article/2074956/learn-java/icontract--design-by-co… (they are plenty others, look at the end of https://en.wikipedia.org/wiki/Design_by_contract in the language support) In fact you are pointing to at the whole benefit of contracts when you say that you can call assert or another method: of you own : the good thing is that they are not linked to your code logic, they are here to check things that you did not anticipate where they could happen. You express what is correct for each method on entry, exit, about the state of the object and the checks are injected into your code... And you see this method that you would never have thought it could do that in this improbable place ... :) It is just a different way of checking that things are running ok under the hood Ah, and I am not against asserts or breakpoints, using contracts does not forbid you to use assert: ... :) -- Alain

Feb. 26, 2016

Setting the font for a spec button

by Stephan Eggermont

Makes it possible to use icon fonts Stephan

Feb. 26, 2016

Re: [Pharo-dev] "error: 'math.h' file not found" when building the new VM

by Alexandre Bergel

> ouch! > this is a known problem in windows so when I read math.h I assumed it was on itâ¦ I should have read the full message before sending you to read ;) > > those kind of errors happen usually because MacOSX10.6.sdk is not thereâ¦ did you check it? > which xcode version and gcc version are you using? Oops, I have just installed the SDK. No more error of math.h But I have another due to libgcrypt:-( Here is the trace of the build.sh -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= checking for _FILE_OFFSET_BITS value needed for large files... no checking for ld used by GCC... /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/ld checking if the linker (/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/ld) is GNU ld... no checking for shared library run path origin... done checking for libssl... no checking for libgcrypt... no configure: error: cannot find OpenSSL or Libgcrypt, try --with-libssl-prefix=PATH or --with-libgcrypt-prefix=PATH make[2]: *** [thirdParty/libssh2/src/libssh2-stamp/libssh2-configure] Error 1 make[1]: *** [thirdParty/libssh2/CMakeFiles/libssh2.dir/all] Error 2 make: *** [all] Error 2 ~/Desktop/VM_TMP/pharo-vm/build> brew install OpenSSL Warning: openssl-1.0.2a-1 already installed ~/Desktop/VM_TMP/pharo-vm/build> brew install Libgcrypt ==> Downloading ftp://ftp.gnupg.org/gcrypt/libgcrypt/libgcrypt-1.6.3.tar.bz2 Already downloaded: /Library/Caches/Homebrew/libgcrypt-1.6.3.tar.bz2 ==> ./configure --disable-silent-rules --prefix=/usr/local/Cellar/libgcrypt/1.6. ==> make ==> make check Please report to http://bugs.gnupg.org ====================================== make[2]: *** [check-TESTS] Error 1 make[1]: *** [check-am] Error 2 make: *** [check-recursive] Error 1 READ THIS: https://git.io/brew-troubleshooting ~/Desktop/VM_TMP/pharo-vm/build> -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= ~/Desktop/VM_TMP/pharo-vm/build> gcc --version Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.11.sdk/usr/include/c++/4.2.1 Apple LLVM version 7.0.2 (clang-700.1.81) Target: x86_64-apple-darwin15.2.0 Thread model: posix ~/Desktop/VM_TMP/pharo-vm/build> No idea whatâs going onâ¦ Help :-) Alexandre > > Esteban > > >> >> Alexandre >> >>> >>>> On 26 Feb 2016, at 11:24, Alexandre Bergel <alexandre.bergel(a)me.com> wrote: >>>> >>>> Hi! >>>> >>>> I am trying to build the VM, according to the instruction given on https://github.com/pharo-project/pharo-vm >>>> However, I get an error: >>>> >>>> eloper/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.6.sdk' >>>> /Users/alexandrebergel/Desktop/VM_TMP/pharo-vm/src/plugins/JPEGReaderPlugin/JPEGReaderPlugin.c:10:10: fatal error: 'math.h' file not found >>>> #include <math.h> >>>> >>>> Where this math.h is supposed to be? >>>> >>>> Cheers, >>>> Alexandre >>>> >>>> -- >>>> _,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;: >>>> Alexandre Bergel http://www.bergel.eu >>>> ^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;. >>>> >>>> >>>> >>>> >>> >> >> -- >> _,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;: >> Alexandre Bergel http://www.bergel.eu >> ^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;. > -- _,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;: Alexandre Bergel http://www.bergel.eu ^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;.

Feb. 26, 2016