- Pharo-users - lists.pharo.org

Glamour Magritte Example Broken

by Gareth Cox

Hi all I've just tried to use GLMAnnouncingCollection and found something odd. When you use it and its passed into a block (such as TableColumn computation:) it passes in the whole collection, not each item. Change the collection to OrderedCollection and it works as expected (except you lose the behaviour of GLMAnnouncingCollection). So, to find out how this is used I go to the examples provided, specifically "Magritte presentation". This has the following comment: "self new magritte openOn: GLMMagrittePersonExample sampleData" "GLMMagrittePersonExample sampleReset" "note, sampleData is *aGLMAnnouncingCollection*" This does not work as expected (or indeed how it used to). I've looked at this before and done work with Magritte using this example with Diego Lont and Stephan Eggermont. Its definitely become broken since the last time I looked at it. Can we confirm? Thanks -- Gareth Cox IT Manager/Developer Inspired Org (PTY) Ltd email: gareth(a)inspired.org <mailto:gareth@inspired.org>

Aug. 4, 2015

MongoDB: console commands? query embedded indexed fields?

by Sabine Manaa

Hi, I have 2 questions concerning use of mongoDB classes: 1) how can I send mongo console commands directly from smalltalk 2) how to query on an embedded collection with an index Model: I have trips and each trip has an embedded collection of N receipts like this: { "tripName" : "trip 1", {"receipts" : [ {"receiptDescription" : "receipt 1" } {"receiptDescription" : "receipt 2" } {"receiptDescription" : "receipt 3" } ], } Index: For quick search, I created an index on the embeded[1] receipts with this command at the mongoDB console in a terminal (NOT in smalltalk) (mongo console starts with mongo in the MongoDB/bin dir): db.Trips.createIndex({"receipts.receiptDescription":1}) with a command like this in the mongoDB console db.Trips.find({"receipts.receiptDescription":"receipt 1"}) I get the resulting receipt. Before, I have to set the database with "use {databasename}" in thr mongodb console My questions: 1) how can I send mongo console commands directly from smalltalk, e.g. use database, set index etc. Is this possible? I did not succeed with the mongo command: method, it always returns "no such cmd". 2) how can I search for a receipt which is indexed as described from smalltalk? I did not succeed with the description [2] I am not sure if it is covered by it. Regards Sabine [1] http://docs.mongodb.org/manual/core/index-multikey/#index-arrays-with-embed… [2] http://smallworks.eu/web/blog/2013-07-18-Voyage-advanced-queries -- View this message in context: http://forum.world.st/MongoDB-console-commands-query-embedded-indexed-field… Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com.

Aug. 4, 2015

Re: [Pharo-users] Comparison for SequencableCollection

by jtuchel＠objektfabrik.de

Am 04.08.15 um 00:22 schrieb webwarrior: > We're drifting too much into philosophy here. Meaning of this, meaning > of that... Thanks. I'd love to be clever enough to be a philosopher. > > 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. The only thing I am worried about here is that you use the word "intrinsic". Other than that, you are fully correct. In daily life, we've grown accustomed to a being the letter before b. Not intrinsically, but practically. Not sure what exactly this has to do with Collections that hold any kind of objects. Please implement comparison and move it to the Pharo base library, because, since there is no intrinsic meaning to comparing collections anyway, you can do whatever you want, as long as it is well-defined and it can be overridden if needed. Just because I am saying this is pollution and questionable, you shouldn't keep yourself from doing so. > > 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. Oh, now it's you who drifts into philosophy. You just said it's well defined and therefor okay to have some default ordering. Now daily life jumps in and jumps onto your fine arguments and breaks everything. And then, the whole Unicode catastrophe around differences between languages and cultures just shows that oversimplifying can be expensive errors. You say nobody questions if A<B, admitting it may be exaggerating. In reality there are several billions of people on the planet who wouldn't really care because neither A nor B are used in their mother language. This, of course, is philosophocal and I apologize immediately. My point is that lexical ordering is business logic, and we currently see what a mess we made when we decided to use the roman alphapet exclusively for lexical ordering. We just locked out 40-50% of the human race from having any meaning in ordering. Maybe lexical ordering should be pluggable, just because it is not intrinsic. Because the order of things is often dependent on context. And context is something that is not well suited for a base class library if it is not designed as something extendible/configurable. I admit I am at the edge of philosophy here, because what the heck does this "oh, the chinese use pictures instead of letters" have to do with an abstract definition of comparison between collections? > > 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. Fair enough. Most of the times, you implement your real-life meaning of comparison and equality to make good use of such features. Or you don't care if there is no order, just the need for fast retrieval based on criteria you don't care about. I am not familiar with the definition of ADT, but "algebraic" seems to indicate there is some mathematical set of base rules that needs to be met by those data types, right? You make them algebraic by making sure they follow the rules of algebra. Once that's ensured, everything else is just that: algebra. Again: A Sequenceable Collection makes sure objects are kept in a defined order. "Definition" here is either some kind of sorting (you use or override equality and comparison) or the order of adding to the collection, or something else. That is the job of a SequenceableCollection. Nothing more, nothing less. But please let's end this discussion, I will try not to write anything more on the topic. I stated my opinion which you asked for. If you don't agree, good. I don't consider myself intelligent enough to redefine Smalltalk, but in this case I have the feeling your idea doesn't qualify for the base libraries. You know that by now, we disagree. good. Joachim -- ----------------------------------------------------------------------- Objektfabrik Joachim Tuchel mailto:jtuchel@objektfabrik.de Fliederweg 1 http://www.objektfabrik.de D-71640 Ludwigsburg http://joachimtuchel.wordpress.com Telefon: +49 7141 56 10 86 0 Fax: +49 7141 56 10 86 1

Aug. 4, 2015

Re: [Pharo-users] Fuel Error

by Sean P. DeNigris

Mariano Martinez Peck wrote > Those kind of errors... Thanks for the detailed answer! It seems that anObsoleteXyz snuck into my graph :/ Once I replaced it with the-class-I-thought-it-was, everything straightened out. ----- Cheers, Sean -- View this message in context: http://forum.world.st/Fuel-Error-tp4840866p4840872.html Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com.

Aug. 4, 2015

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. 4, 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. 4, 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. 4, 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. 4, 2015