Squeak-dev October 2007

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151 participants
195 discussions

MC15 nasty bugs strike 1
by Keith Hodges 02 Oct '07

02 Oct '07

I have found the problem which led to packages needing a recompile if instance vars are changed significantly. This was leading to image crashes when upgrading the dev-image package universes. Recent Omnibrowser changes provided a perfect test scenario. This was our big showstopper bug! cheers Keith ========= The following is for documentation of the loading process and is a very good reason why SystemEditor is much better solution. The loading process. [preloadOver:] When loading classes, first of all MC removes all class extenstions for a class and its subclasses, and saves them for later. This avoids problems later in the load (see **). Then MC attempts to change the class to a union of the old and new class definitions in order that as many methods as possible, old and new will compile. This change prompts a recompile of the class. Old methods which happen to use new inst var names for temp's will fail to recompile with Syntax Errors. At this stage such SyntaxErrors being resumable are ignored. For each method being added the obsolete method (if there is one) is removed. [*] part of the show-stopping bug was caused by failing to remove the obsolete methods at this point. This would cause the next next class recompile to fail due to undeclared items in the obsolete methods When loading methods, each method being added is compiled ready to be added later. This compilation may fail if the unioned-class definition failed to compile earlier hence the importance of *. [removal] Methods that are no longer needed are removed. If the method is an '-override' the old method is found and reinstated. [install] Loading Classes: The class is then changed to the required definition. If this changes the definition then a recompile will occur again. Methods which are not for this class definition and refer to removed instVars will fail to recompile at this point. [this used to include obsolete methods which were not being removed as indicated above*] [**] NOTE: At this point class extensions from other packages will fail to recompile if they are accessing inst vars directly, and those instvars have been removed. The solution is to to remove extensions first until such time as they will recompile or become superseded by a new method Loading Methods: if the previous compilation failed, it will be retried in the context of the new class definition. The compiled method is added to the class and logged to changes [ postinstall ] Loading Classes: Class extensions that were removed to begin with are re-compiled and installed. Classes effected are recompiled (not sure why this is necessary but it is!). Loading Methods: FFI field definitions are loaded (first) and #initialize is run (last) [ postLoad ] Loading Classes: Restored class extension methods have their observers notified. Loading Methods: Methods have their observers notified.

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Re: Fear and loathing of the "perification" of Smalltalk
by Peter William Lount 02 Oct '07

02 Oct '07

Paolo Bonzini wrote: >> What does the Squeak Compiler convert curly braced code into? > > Sending #new: and #at:put: > >> Certainly in another version of Smalltalk there will be two >> evaluators: one that returns the value of the last statement as >> normal, plus one that stores the results of each statement as it's >> evaluated into a collection. > > You don't know what you're speaking about. Ergo, you're a troll. > > Paolo > Hi Paolo, Eh? What? You're calling me a troll? If that's the case that's just silly and very inappropriate since you are deeply mistaken. You know me Paolo, we've had interactions over the years, and I'm quite surprised that you'd stoop to person an hominem attacks by calling me a troll. Besides I don't follow the logic of how on earth you could interpret what I wrote in the series of postings under the subject 'Fear and loathing of the "perification" of Smalltalk'. Maybe you didn't understand what I meant. If that's the case I apologize for your misunderstanding as my posting mustn't have been clear - I'll attempt to communicate what I meant again. ------ Two Evaluators For Smalltalk Like Languages 1) You'd have to agree that the normal Smalltalk evaluator simply returns the object from the last statement in a sequence of statements? Right? For example, the value of the following block is the value of "c", whatever that is: "[ a. b. c ] value". Let's assume that the variables are defined in the method or are instance variables. 2) You'd have to agree that it would be possible for a NEW evaluator to return a collection containing the values of ALL the statements in a sequence of statements? Right? For example, the value of the following block is the collection with elements "#(a b c)": "[ a. b. c] values". Note that the message "values" and not "value" was sent to the block. The "values" message asks the block to evaluate itself "collecting" up the objects from each statement and place them into a collection; by default an ordered collection would be a good choice since the number of objects wouldn't be known at run time. So, assuming that you understood the two above paragraphs then you'd have to agree that (2) is a valid option or alternative to (1). As such you'd have to agree that I do know what I'm talking about, since it's clearly explained in the above two paragraphs. Simply put Blocks can do the job that curly braces do leaving curly braces out of Smalltalk syntax and available for a far better purpose. While I now recall someone telling me that squeak did implement the curly braces as a quick compiler hack a couple years back (that just generates other Smalltalk code like a macro would in many other languages), I'd forgotten that during the recent conversations until reminded about it. That was my failing for sure, but not a significant one and certainly one that's not relevant to the fact that the second option for the existing evaluator would be valid and useful in Smalltalk or a language inspired by Smalltalk such as ZokuScript. The other version of Smalltalk that I was referring to is the one that I'm working on, ZokuTalk and the language inspired by Smalltalk, ZokuScript. ZokuTalk is intended to be as close as possible to Smalltalk-80 style languages such as Cincom Smalltalk, IBM VisualAge or Squeak Smalltalk; that's to support code portability. ZokuScript is meant to take Smalltalk to a whole new level. ZokuTalk will be rewritten into ZokuScript on the fly at compile time or at runtime and then that ZokuScript will be compiled into native code. No byte codes to mess things up.* ------ * So Paolo, maybe you'd have to admit that there could possibly be a chance that I might know what I'm talking about. The next time before you accuse someone of being a troll - which is a highly aggressive ad hominem personal attack and an attempt to stifle free speech and the discussion - you'd have the courtesy of asking what the person meant so that they can explain it to you. Just because you don't understand something that someone says doesn't mean that they are a troll with some devious purpose that you imagine. Also, because someone doesn't hold your point of view that doesn't mean that they are a troll either - it just means that they have a different point of view. I hope that I've shown with the above two paragraphs that an alternative evaluator for Smalltalk added to blocks can be in fact made to work at the language level. How to implement it is certainly a question. I simply don't think that implementing it with curly braces is the way to go since that adds, in my view, unnecessary syntax when we could use Blocks with a second "collecting" evaluator for the statements. There are many smart implementors in this list and elsewhere who can figure out the best way to implement blocks in this manner. All the best, Peter William Lount peter(a)smalltalk.org

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PR Team Follow Up
by CHRIS CUNNINGTON 01 Oct '07

01 Oct '07

Dear Squeakers, I'm writing this to follow up our recent effort to get Squeak By Example Slashdotted. Unless somebody has evidence to the contrary, I think our effort to get Slashdotted is -- for now -- at an end. I made the PR Team request on Wednesday. At least five people did submit the story to Slashdot. The status of my submission was 'pending' for two days, until Friday. Then it was rejected. I'm assuming that the others have also been rejected. My impression of this is that the editors did not know what to do with the story and so left it in the Firehose section to see what kind of reaction the story had on the Slashdot forums. There was not a great deal of forum activity for the story, and so I think they took that as an indication that they could pass the story over. That's OK. One Slashdoting does not a new future for Squeak make. What I think is most important here is how positive and willing the Squeak community was to take this idea seriously. Nobody thought trying to get Slashdotted was a waste of time. It is my impression that people in the Squeak community are ready for a higher profile. If the community starts to think in this way, and this is something that Squeakers want, then we can make it happen over time. Chris Cunnington PR Team leader

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Pending fixes for 3.10 (was Re: [ANN][Squeak-dev Mini Image] Version sqMinidev07.09.1)
by Jason Johnson 01 Oct '07

01 Oct '07

On 9/21/07, Edgar J. De Cleene <edgardec2001(a)yahoo.com.ar> wrote: > > Once I said MinimalMorphic should start as 7200 , now we are to 7143, not > many red test but is important we wait the fix of Delay and fonts problems. What is holding back these fixes? Just resource time to put them in, or is there something else like missing tests? In other words is the ball in your court or are you waiting for some outside resource that may not be aware they are a bottleneck? :)

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Searching the image for text
by Jimmie Houchin 01 Oct '07

01 Oct '07

Hello, I have always wanted the ability to sometimes just search the image for a string of text. Just like I would in an OS per se. I might see a morph that has some text in it and I want to know the code from whence it came. Or any other number of reasons. Is there a way to do this? As Squeak is OS like in many ways, it seems like this would be there. Any wisdom greatly appreciated. Jimmie

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