Squeak-dev October 1998

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Re: The State of Exceptions
by Pascal Bourguignon 11 Oct '98

11 Oct '98

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Re: prototypes vs classes was: Re: Sun's HotSpot
by Alan Kay 11 Oct '98

11 Oct '98

Dan -- There are many ideas in REBOL that I like -- and many of these could provide some clues for what the intermediate scripting in Squeak might be like. Note how much of REBOL resembles LOGO and BOXER. I think the functional, data, and object aspects of REBOL could be integrated quite a bit better ... Cheers, Alan ------ At 6:59 PM -0000 10/10/98, Dan Shafer wrote: >Alan Kay wrote: >> >> Folks -- >> >> Just a gentle reminder that I took some pains at the last OOPSLA to try to >> remind everyone that Smalltalk is not only NOT its syntax or the class >> library, it is not even about classes. I'm sorry that I long ago coined the >> term "objects" for this topic because it gets many people to focus on the >> lesser idea. >> >> The big idea is "messaging" -- that is what the kernal of Smalltalk/Squeak >> is all about (and it's something that was never quite completed in our >> Xerox PARC phase). ><snip> > >Messaging has always seemed to me to be the heart and soul of not only >Smalltalk but objects in the broader sense. > >To that end, has anyone else here looked at REBOL >(http://www.rebol.com), a new Net-specific scripting language with >objects including Net-native data types like URLs and email addresses? >It's not ready for prime time IMNSHO, but it points in some potentially >very interesting directions. >-- >|=================================================| >| Dan Shafer, Executive Technical Producer and | >| Editor-at-Large, CNET's Site for Site Builders | >| dshafer(a)cnet.com - Preferred Method of Contact | >| http://www.builder.com - Main Builder Site | >|http://buzz.builder.com - Online Discussion Area | >|http://web.builder.com - Semi-Annual Conferences| >| Save the Dates - Dec. 7-9, 1998, Web.Builder | >| New Orleans Strikes Again! | >|=================================================|

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SNA Connectivity?
by Ken G. Brown 10 Oct '98

10 Oct '98

Is anyone working on SNA connectivity from within Squeak? Ken G. Brown

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Re: Sun's HotSpot
by Dwight Hughes 10 Oct '98

10 Oct '98

David Stes wrote: > > On Fri, 9 Oct 1998, Steve Dekorte wrote: > > > > I've had the same experience and also refuse to do DO with languages that don't > > support forwarding. Likewise, I wouldn't consider writing a visual programming > > environment in a class based language. > > This happens to be a list about a class based language ! I think he is referring to ADT (Abstract Data Type) based languages where the various ADT definitions and their related functions are called classes (no relation to Squeak/Smalltalk classes as objects). ADTs are a way to avoid the advantages of using actual objects and general polymorphism while retaining most of the inflexibility and complexity of "standard" procedural languages <I would grin but it's not really a joke>. -- Dwight

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Re: Sun's HotSpot
by Steve Dekorte 09 Oct '98

09 Oct '98

David Stes <stes(a)mundivia.es> wrote: > > I've had the same experience and also refuse to do DO with languages that don't > > support forwarding. Likewise, I wouldn't consider writing a visual programming > > environment in a class based language. > > This happens to be a list about a class based language ! I like to think of Squeak as being more of a unitarian sort of project. > > Both are situations where the inflexibility > > of the language result in the developer either writing a language on top of a > > language or realizing what a miserable hack that is and looking for a better > > language. > > The class system of Squeak can hardly be called a miserable hack ... I agree. I only said writing a visual programming environment on top of it would be. Just as Java is not a miserable hack, but trying to do DO in it would result in one. Both are examples of where the developer runs into the walls of the langauge. Of course you have to run much father to find the walls in Squeak/Smalltalk than in Java. Steve

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Re: Sun's HotSpot
by Steve Dekorte 09 Oct '98

09 Oct '98

Steve Dekorte <steve(a)dekorte.com> wrote: > "Jarvis, Robert P." <Jarvisb(a)timken.com> wrote: > > AFAK they can support the same functionality. I guess I > > don't see that prototypes have any great advantages over > > properly implemented classes.. I forgot to explain what protos are. Think about the transition from functional to class-based languages like simula. What happended? State and behavior got closer together. Then came Smalltalk. What happened? The behavior got (essentially) stuck into associative arrays, so you didn't statically link to methods - you called them dynamically. But you still had static connections to state(variables) in your methods. Then came the prototype-based langauges. They just finished what Smalltalk started. They put both state and behavior for an object into an associative array. It's a natural progression. Steve

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RE: Sun's HotSpot
by Ken Dickey 09 Oct '98

09 Oct '98

>Can someone sum up the >advantages of a prototype-based inheritance model? I'll take a quick shot at it. The tradeoff really becomes apparent with different usage scenarios. If you make a lot of objects which all share common characteristics, the class based model works fine. When you start making a lot of idiosyncratic objects, having a class per object makes much less sense. I did not really see the advantage of the prototype approach until I started working with Apple's SK8 (pronounced 'skate') multimedia IDE. The SK8 environment presents the author/programmer with a bunch of pallets. So instead of building up from the bits, you typically make a clone or child of a fairly heavyweight prototype object. Children can inherit from multiple parents. It is kind of a grab, drop, add behavior scenario. Like grab a window frame, grab a movie, grab some background picture, grab a few sounds, make some hotspots play sounds and movies, etc. Hook things up and add behaviors (methods) and you have a MM application. You can change a 'parent' and either propagate changes to children or not. When you open/inspect an object, you see both it's state (ivars) and behaviors (methods), so you tend to think of dealing with individual objects. Note that there is a big change in level here. As I noted, the media authoring objects tend to have most of what you need and therefore be fairly heavyweight (i.e. have a lot of ivars and methods). This Authoring level can be built on top of an underlying class based system given some introspection and reflection. Instance methods are a great help. You may have noticed by now that Morphic shows some tendencies in this direction. Heh, heh. ;^) Cheers, -KenD

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Re: Sun's HotSpot
by Steve Dekorte 09 Oct '98

09 Oct '98

David Stes <stes(a)mundivia.es> wrote: > In fact, for GUI development, it's an advantage to have a class based > system : you can have a class 'Button' and instances are _specific_ > buttons with specific titles, labels and so on. But can't prototypes support the same functionality with more flexibility? Steve

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Re: Sun's HotSpot
by Ian Piumarta 09 Oct '98

09 Oct '98

> Personally, I view this as a bug. Not having an object indirection pointer > makes doing "Object become:" highly inefficent. Java doesn't have the equivalent of "become", and never will (or so I've been told by a Sun JVM insider). Besides, a direct-pointer #become: can be pretty efficient (see the one in Squeak for example) under the right conditions. > Without a very efficent "become:" it's gets MUCH harder to do transparent > proxying, which is real handy for distributing your objects across networks or > storage devices. Sigh. Been there, suffered that. It's the main reason why I infuriate my boss by refusing point-blank to do any (distributed systems) research prototyping whatsoever in Java. The only languages that I've had positive experiences with in this area are Smalltalk and Objective Caml. (In C++ and friends I usually end up implementing the equivalent of an object table and hiding everything behind smart pointers -- something else that's impossible to do transparently in Java.) Sad, but c'est la vie. End of off-topic ramble... Ian

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ServerDirectory openFTP problems
by russell.allen＠firebirdmedia.com 09 Oct '98

09 Oct '98

G'day! I've been really enjoying the new email client and web browser, (there's a definate buzz in emailing the Squeak mailing list from within Squeak) and have been delving into Squeak's networking code. However, trying to add my free Xoom (www.xoom.com) web account to the file list as a server, I was having problems when openFTP was changing to passive mode. The problem was the code in the method openFTP in class ServerDirectory: so sendCommand: 'PASV'. resp _ (so getResponseUpTo: FTPSocket crLf) first. "Tells which port on server to use for data" Transcript show: resp; cr. (resp beginsWith: '227 Entering Passive Mode (') ifFalse: [ so sendCommand: 'QUIT'. so destroy. ^ self error: 'can''t get into passive mode']. Instead of returning '227 Entering Passive Mode (', Xoom returned: '227 PASV(', which broke the method. changing to: so sendCommand: 'PASV'. resp _ (so getResponseUpTo: FTPSocket crLf) first. "Tells which port on server to use for data" Transcript show: resp; cr. (resp beginsWith: '227 ') ifFalse: [ "Check for Entering Passive Mode" so sendCommand: 'QUIT'. so destroy. ^ self error: 'can''t get into passive mode']. seems to fix the problem. I don't know whether this is only a Xoom problem or not, but my ability to solve this problem in a complicated piece of software such as Squeak fairly quickly and simply is nothing short of amazing. Why isn't all progamming like this? Thanks, Russell

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