August 2015 - Pharo-users - lists.pharo.org

Re: [Pharo-users] Fuel Error

by Mariano Martinez Peck

Hi Sean, Those kind of errors are the most complicated to debug because it means there is mostly a problem at the serialization. I mean, the balance between what the serializer thought it wrote, and what the materializer tries to materialize, doesn't match. So the error tells you nothing...just that the stream is not as the materializer expects it. One of the common cases of this error is that the graph changed while being serialized. In fact...not even that...more precise... At serialization time, Fuel does 2 parts: first, it kind of "visits" / traverses the graph. On a second step it writes the stuff into the stream. If the graph of objects changed after it has been visited, that means, when we are writing it into the stream, depending in the graph change, we may throw FLObjectNotFound (see #signalWith:). However...if the graph changed while being "traversed" which happens BEFORE writing the stuff into the stream, or ... if the change is something we cannot easily track (like object not found), then it is likely the resulting stream is not correct. Note that is not very easy to have kind of a checksum if you are serializing a graph of objects that can change while writing it. Some workarounds are: 1) Analyze what gets written into the stream (I can help you with this), because sometimes, the traversal of the graph is much bigger than you imagine, and you end up serializing things you don't know. And that things you don't know, could change frequently. For example, I remember once I ended up serializing a morph, that then referenced the World, and so the cursor and mouse position etc. So..it was IMPOSSIBLE for the graph not to change while being serialized. This point may likely come with a "large" resulting stream size. 2) Try to do a "copy" or similar of your chart. If you know what you change frequently you can either do a copy or similar 3) If you know what could change, you may want to use some of the Fuel hooks to avoid those fields, or replace them or .. 4) Run the serialization with a higher processor priority so that it's less likely others changed your graph of objects. Yes, hacky. All of these points is only if the problem you mention is because the graph changes while being serialized. If not...then I am not sure what can be. Could be a bug. Which Pharo version is it? Cheers, On Mon, Aug 3, 2015 at 8:56 PM, Sean P. DeNigris <sean(a)clipperadams.com> wrote: > While materializing, I'm getting a Fuel error that's ground one of my > projects to a halt. Luckily, there's not *too* much data involved, but I'd > like to get it back. > > <http://forum.world.st/file/n4840866/Screenshot_2015-08-03_19.png> > > Ever see anything like this? Any idea what the problem is? > > Thanks in advance. > > > > ----- > Cheers, > Sean > -- > View this message in context: > http://forum.world.st/Fuel-Error-tp4840866.html > Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com. > > -- Mariano http://marianopeck.wordpress.com

Aug. 4, 2015

Re: [Pharo-users] Comparison for SequencableCollection

by Ben Coman

On Mon, Aug 3, 2015 at 12:04 AM, Peter UhnÃ¡k <i.uhnak(a)gmail.com> wrote: >> (a b c) = (b a c) if a = b >> >> (a b c) < (b a c) if a < b >> The semantics are well defined. A comparison between sequenceable collections compares each element in sequence. This makes intutive sense. > Since you mentioned JavaScript, you should know that you can't compare > arrays with ==, because it does object comparison. I don't understand the introduction of == to the argument. Its not mentioned previously. >> No. Sorted collection maintains order of its elements, and I'm talking >> about order on [the set of] sequencable collections > > This will make sense only if the objects have overriden their #=. It seems okay to me for the user to be responsible for ensuring elements put into SequenceableCollection can be compared. > Which also means that it is not very useful to use #<, because you can't > define order without overriding #=. > > Compare it to sorting a collection, where you can either do #sorted, which > will do "a <= b" by default, but you can still do #sorted: and specify the > sort order, ditto with PluggableDictionary etc. > So if anything, it would make more sense to be able to block-based testing > (without relying on #<), because more often then not you will have your > values wrapped in some (bigger) objects. > > And finally "Because in almost every programming language..." is not an > argument. Learning things from other languages *is* a reasonable argument, but it should not be the major consideration. cheers -ben > You could argue that "1 + 2 * 3" should return "7", because that's how every > language does it and that's how mathematicians did it for thousands of > years. And yet Smalltalk happily returns "9" and yet it makes sense, and > some could argue that it's even better. > > Peter > > On Sun, Aug 2, 2015 at 4:59 PM, Alexandre Bergel <alexandre.bergel(a)me.com> > wrote: >> >> > I'd say it is questonable if SequenceableCollections should be >> > comparable by default. >> >> +1 >> >> Alexandre >> -- >> _,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;: >> Alexandre Bergel http://www.bergel.eu >> ^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;. >> >> >> >> >

Aug. 4, 2015

Fuel Error

by Sean P. DeNigris

While materializing, I'm getting a Fuel error that's ground one of my projects to a halt. Luckily, there's not *too* much data involved, but I'd like to get it back. <http://forum.world.st/file/n4840866/Screenshot_2015-08-03_19.png> Ever see anything like this? Any idea what the problem is? Thanks in advance. ----- Cheers, Sean -- View this message in context: http://forum.world.st/Fuel-Error-tp4840866.html Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com.

Aug. 3, 2015

Re: [Pharo-users] Garage, Glorp, PostgreSQL and Cursors

by Esteban A. Maringolo

2015-08-03 16:20 GMT-03:00 Esteban Lorenzano <estebanlm(a)gmail.com>: > yesâ¦ just that is not accurate :) > is basically like that, just that DBXTalk is not a driver, is an umbrella project. The OpenDBX drivers is still called OpenDBXDriver :P TooManyAbstractionsException signal. ;) Esteban A. Maringolo

Aug. 3, 2015

Re: [Pharo-users] Comparison for SequencableCollection

by webwarrior

We're drifting too much into philosophy here. Meaning of this, meaning of that... I'd argue there is no intrinsic meaning in statements such as "string A is less than string B". But it is useful to have order defined on set of words and character strings in general. Lexicographic order has some useful properties and has been used in dictionaries for a long time. Now nobody (OK, maybe I'm exaggerating a bit) questions whether strings should have comparison and what ordering to use. We can easily generalize this to all sequences with elements that can be compared - and that's what designers of programming languages did. So it became like de facto standard. Note that default lexicographic ordering for strings is not always desired - e.g. some file browsers have option of "numerical order" (which accounts for numbers - "10" comes after "9" and so on). Still it's not a reason to abandon default ordering. On a side note: some functional programming languages with ADTs (algebraic data types) automatically provide structural equality and comparison for all ADTs, including user-defined, where it is possible. And it's awesome, because it saves you from writing boilerplate code. Again, you could say that there is no meaning in comparison of, say, some n-ary trees of bools. But it has practical use: a datatype must implement comparison to be used in sets and dictionaries that are based on search trees. On 03.08.2015 16:37, jtuchel [via Smalltalk] wrote: > > ...snip... > -- View this message in context: http://forum.world.st/Comparison-for-SequencableCollection-tp4840704p484085… Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com.

Aug. 3, 2015

PharoByExample Announcements chapter

by Peter UhnÃ¡k

Hi, shouldn't there be Announcements chapter in the new PharoByExampleUpdated book? Because I don't see it there and I think it should be there, since currently I don't see any authoritative source of information for people about Announcements. Thanks, Peter

Aug. 3, 2015

Re: [Pharo-users] protobufs for Pharo

by Paul DeBruicker

Hit 'send' inadvertently. Goran Krampe has gotten it as far as it is now. I may have a use for protobufs to access a 3rd party library and would be willing to help get it finished in the event anyone else is interested. Paul DeBruicker wrote > http://www.smalltalkhub.com/#!/~gokr/Protobuf > > > Its not totally done yet > Benjamin Pollack-2 wrote >> Hey all, >> >> Has anyone implemented protobufs for Pharo yet? Iâve not managed to find >> any examples, so I assume the answer is ânoâ, but I thought Iâd check >> here before rolling up my sleeves and writing one myself. (My specific >> target here is to write a RethinkDB driver, so if someone has magically >> also done *that*, please let me know, too.) >> >> Thanks, >> --Benjamin -- View this message in context: http://forum.world.st/protobufs-for-Pharo-tp4825504p4840855.html Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com.

Aug. 3, 2015

Re: [Pharo-users] protobufs for Pharo

by Paul DeBruicker

http://www.smalltalkhub.com/#!/~gokr/Protobuf Its not totally done yet Benjamin Pollack-2 wrote > Hey all, > > Has anyone implemented protobufs for Pharo yet? Iâve not managed to find > any examples, so I assume the answer is ânoâ, but I thought Iâd check here > before rolling up my sleeves and writing one myself. (My specific target > here is to write a RethinkDB driver, so if someone has magically also done > *that*, please let me know, too.) > > Thanks, > --Benjamin -- View this message in context: http://forum.world.st/protobufs-for-Pharo-tp4825504p4840853.html Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com.

Aug. 3, 2015

Re: [Pharo-users] Garage, Glorp, PostgreSQL and Cursors

by Esteban Lorenzano

yesâ¦ just that is not accurate :) is basically like that, just that DBXTalk is not a driver, is an umbrella project. The OpenDBX drivers is still called OpenDBXDriver :P Esteban > On 03 Aug 2015, at 20:55, Sean P. DeNigris <sean(a)clipperadams.com> wrote: > > Esteban A. Maringolo wrote >> Garage is... > > Thank you! Very helpful. It seems like this would be a great clarification > to add to http://guillep.github.io/DBXTalk/ , no? > > > > ----- > Cheers, > Sean > -- > View this message in context: http://forum.world.st/Garage-Glorp-PostgreSQL-and-Cursors-tp4840760p4840827… > Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com. >

Aug. 3, 2015

Re: [Pharo-users] Garage, Glorp, PostgreSQL and Cursors

by Sean P. DeNigris

Esteban A. Maringolo wrote > Garage is... Thank you! Very helpful. It seems like this would be a great clarification to add to http://guillep.github.io/DBXTalk/ , no? ----- Cheers, Sean -- View this message in context: http://forum.world.st/Garage-Glorp-PostgreSQL-and-Cursors-tp4840760p4840827… Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com.

Aug. 3, 2015