"I have a mind like a steel... uh... thingy." Patrick Logan's weblog.

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Monday, March 14, 2005

The Race is On -- Where's the Goal Line?

From Infoworld...

What I thought would be a Java lovefest turned into a "How do we fend off Microsoft?" debate.

The consensus was that .Net is a strong technology but that Java provides the advantages and disadvantages of more community participation. While more amenable to community contributions than perhaps .Net is, it is thus more difficult to build a consensus on improvements than the monolithic .Net platform, which is controlled by Microsoft.

For the time being, both Java and .Net shall remain the dominant platforms. There may not be a victor, but continued coexistence for years to come.

I'm curious whether the interesting race is the emerging-yet-not-fully-realized race to "fully" support dynamic languages on these platforms.

Debasing

Danny Ayers writes...

It seems to me that a very large proportion of today’s user-oriented Web applications could run as CRUD. We’ve already got a fair idea how to separate content from presentation. But the business logic is usually all tangled up in a combination of SQL tables (and maybe triggers etc) and objects/procedures or other relatively hard-coded representation...

A part of the reason that middle layer has tended to grow over time is the mismatch between the logic provided by the database and the real-world data it has to manage (...much of this is to do with the design of SQL databases, not Codd’s model). Another problem is... up-front design of database schema... There isn’t much flexibility for continuous development at the back end, so things get pushed forward. Not very eXtreme.

...replacing the back end relational database with a triplestore, SQL with SPARQL and schemas with ontologies. Bit of RESTful HTTP and XML for the transport, bit of XSLT for the presentation layer (with HTML forms, XForms, XMLHttpRequest, whatever you like). There’s no reason why the whole lot couldn’t be generated from a set of statements, although a bit of PHP template hacking may be needed in the interim…

Yes, this is the old Semantic Web chestnut rewritten for a new generation…or rather, the generation that got quicker results with Dbase years back…

The Road Ahead

Mitch Kapor writes...

The challenge now is whether Ray and Groove, which represent forces of architectural innovation, can have a successful impact at Microsoft, which after all, is a large (58,000 person), middle-aged (30 year-old) company. It's hard to know whether the loss of nimbleness due to size and age is a greater challenge to Microsoft than is open source.

Groove and Croquet

Hugh Pyle writes some things about being owned by the borg and innovations...

What will become of Groove now? Good things, I think. After all, the only competitive architecture within a couple of decades is Alan Kay's mallet.
I wonder how Groove and Croquet line up. They seem fairly different on the surface.

Sunday, March 13, 2005

Evolution

Sean McGrath writes about SOAP...

Behind the firewall, nobody can hear you scream and nobody can see your wallet bleed.
Success should also be measured by an ability to evolve. Building a system once is not the challenge.

Wednesday, March 09, 2005

Hypermedia as the Engine of Application State

From Roy Fielding's thesis...

"REST is defined by four interface constraints: identification of resources; manipulation of resources through representations; self-descriptive messages; and, hypermedia as the engine of application state."
(via the REST Yahoo group)

That last one has my attention.

Size Matters

Scott Hanselman writes (via Sam Gentile)...

The Size of the Framework - Sure, it's big. So was Win32, and so is sun.java.*. Programming isn't all Ruby on Rails, you know. :) The redist is 25 Meg? For what you get that's pretty cheap. That'll fit on any pen-drive and can be downloaded in a few minutes via broadband.
I was giving a tour of Squeak Smalltalk to a friend who'd never seen Smalltalk before. I did not have to explain much, just play with some objects, play with Seaside, show some browsers, a workspace, a debugger, look at some code. He got it, in bits and pieces. After a couple hours he was amazed.

He saw that the 3.7 image out of the box is about 15mb. The image I was using was about 22mb. The concept of an image, consisting of "live objects", being persistent, caught on and his eyes lit up. That 22mb contained the persistent objects that we were playing with: Powerpoint-like presentation objects, a 3D scriptable wonderland, rich text being flowed in real-time through multiple arbitrary shapes as I reshaped them. An internet browser, email, etc. A little car and steering wheel that really drives it around. A piano keyboard, and more elaborate instrumentation. All objects in the system, all the code available, all the time, multiple platforms identical, all in less than two dozen megabytes.

Live objects. *That* is amazing and he was amazed.

Web DNA

Wonders Jon Udell...

...despite Steve Ballmer's infamous monkey-dance chant, developers haven't flocked to TerraServer. What's Google's secret? Web DNA and no Windows tax.

Programming Languages

Philip Greenspun on programming languages...

SQL, Lisp, and Haskell are the only programming languages that I've seen where one spends more time thinking than typing.
There are some others to add to the list: Smalltalk, Python, Ruby, SML, etc. But the point is taken.

Bringing it all back home

Sean Mcgrath writes...

Here is the great irony of the Web. It was vastly easier to create a CRUD application (...Create, Report, Update and Delete...) in the days of Dbase II than it is today.

Sometime, somehow, we have to get that functionality back.

Monday, March 07, 2005

Hand-in-Hand

Radovan Janacek projects the downfall of JSR-xxx before WS-xxx.

But perhaps the decline of Java and C# will *coincide* with that of WS-Complexity. More agile approaches are gaining mindshare both for programming in the small as well as programming distributed systems.

Sunday, March 06, 2005

Drawing

Drawing lines in the sand. Chris Ferris is going for a forest vs. trees argument. Carlos responds to Chris...

If this is the new definition, then I would like to hear a simple explanation on how all this baggage helps improve interoperability. Now if SOAP doesn't say anything about interoperability (i.e. it is orthogonal to REST) then a clear consistent and coherent explanation of WS-* would help.
The software worlds own version of March Madness. Now I'm drawing on too many metaphors.

Saturday, March 05, 2005

Zenning

If we want to throw open the road ahead,
We must first push down the wall that’s facing us.

- Hong Yuan (~1533)

Pig Piling

WS-xxx, SOA, ... pig pile!

I agree with Sean. Carlos last few articles have really been a blast reading.

Then over on the other side of the room, speaking of blasts, James is pointing to Jonathan Schwartz's blasting away at WS-xxx hell as well.

From Herr Schwartz...

Web services may collapse under its own weight. No one at the conference said this. Those are my words. I'm beginning to feel that all the disparate web service specs and fragmented standards activities are way out of control. Want proof? Ask one of your IT folks to define web services. Ask two others. They won't match. We asked folks around the room - it was pretty grim. It's either got to be simplified, or radically rethought.

As you know, I also believe simplicity and volume always win - and that today's web services initiatives are in danger of vastly overcomplicating a very simple (really simple) solution.

Friday, March 04, 2005

Marketing

Kurt Cagle comments (to Sean Mcgrath)...

SOA is destined to become the has-been term of 2005, no doubt to be replaced by some other bit of marketing wizardry that is just as meaningless.
(Kurt Cagle works and writes about many things to do with XML.)

Thursday, March 03, 2005

Steering

Ron Jeffries writes...

What is fascinating is that there is no aspect of life or business where things work perfectly, the first time, on time, without any cost. And yet they ask us for that. I believe that it is because, historically, they've had no way to steer, so they don't recognize right away that now they have one.

Wednesday, March 02, 2005

Languaging

Bill de hÓra writes...

You can think of it this way - if Lisp and Smalltalk represent some kind of maxima for expressivity in programming languages then speech act languages like KIF and FIPA-ACL represent a maxima for expressivity in Internet application protocols.
I guess I'll have to figure out what those are.
Enough research and experimentation has been conducted on software agent communication languages over the last twenty years to gives us an inkling of how this might work. The primary problem with this option is social - my guess is that it's more difficult to innovate with application protocols than content models since app protocols tend to be baked into the infrastructure as of the beginning of the 21st Century. And we do tend to think of protocols in engineering terms (interfaces, structures. bits, wires) rather than as linguistic phenomena. It's not called the Internet Language Task Force after all.
Hmm. Interesting. I've been of the mind that there are a small number of application protocols and then another level of protocols could evolve as sequences. (Kind of using DNA bases and sequences as metaphors.) So we need a basic technical structure that will enable a socially acceptable process for evolution.

Minimizing Obligations

Sam Ruby writes...

I personally like conclusions that minimize obligations for all concerned.
Interestingly, Sam is writing about legal issues, but this applies equally well to purely technical design issues.

The REST of Radovan Janecek's List

I've commented on one item from Radovan's list already. Now for the REST...

any other metadata has to be referenced from the representation of the resource
This is good. Semantic nets typically connect data (e.g. "frames" and "slots") and metadata (e.g. "facets" of a slot) directly. I would expect this to be so for a semantic web as well.
use of REST is not always appropriate (even if theoretically it can be used almost everywhere)
This is almost certainly so. But I suppose it is more broadly appropriate than its current range. And less clear is what is more appropriate in those other cases. Certainly there are cases where pre-existing systems are more appropriate. But what of the up-and-coming distributed systems technologies?
REST might be inappropriate especially if the integrated legacy system defines its own non-RESTful abstractions (e.g. SAP's BAPI).
Certainly there will be these cases. But I'm not sure SAP R3 can be put in that category. First, SAP has provided at least a couple of web-services-like interfaces to R3 and newer components. This is settling into the Netweaver/XI integration platform.

I don't know much about this yet, but I don't see why REST would be incompatible. One of the best presentations at OSCON 2003 was convincingly about a Perl and REST interface to R3.

use of REST is especially appropriate for generic system-level services that are expected to be used by robots (registry, security, management, reporting)
I think you are underestimating what a "robot" (i.e. an "interpreter" of semi-structured information) can do. See the Experiments with OVAL paper for a variety of examples using very modest software.
REST is appropriate for hypermedia, of course ;-)
Maybe a good discussion could be about what is suitable for representation as a hypermedia?
building REST applications, WS-* should be used wherever possible to ensure interoperability
Maybe this should be turned around a bit to say that WS-* should be defined to be compatible with the web.
RDF/OWL is more important for REST applications than it seems today
I think generally we need to learn how to build more evolvable application-specific semantic web interpreters. I know a little about RDF and less about OWL, although I am familiar with older semantic net languages. I think this statement could be so. But again referring to OVAL, a lot can be accomplished without getting to deep into heuristics.

Resources

Danny Ayers has a new blog on grid computing and such. One of his first posts is a look at WS resources and RDF. He lays it out nicely and has some good questions around how these seemingly related approaches might actually be compatible, or not.

Semantic Web Interpreters

A couple of inspirations come to mind that I periodically reference here for multiple reasons. Thinking about semantic web interpreters bring these to mind today.

These sources should be absorbed as fundamental background for building RESTful interpreters.

Good Enough

Carlos Perez on SOAP and REST...

If WS-Security is rarely used, HTTPS is good enough and interoperable web services is via XML Schema validation of documents then it becomes less clear what exactly SOAP brings to the table.

SOAP adherents say REST can't be made reliable. However, argue that point with Bill de Hora who recently published HTTPLR a reliable way of transmitting messages via HTTP. The spec is consistent with HTTP semantics rather than extending or abusing them. In otherwords, reliability without the extra baggage of SOAP.

Tuesday, March 01, 2005

Moreover

There are a couple threads that could be tied together.

Radovan Janecek writes about REST...

A resource has to return not only 'data' but also a contract that tells how to work with this resource further - i.e. what to POST and when. In case of browser-based applications, this is somehow solved by HTML. Otherwise, I think WSDL can be used.
I don't think this is quite so. The browser is interpreting representations at runtime. WSDL will present a description of the shape of the runtime data, but the application using the WSDL will still have to do the interpreting.

The choice is definitely not confined to a browser interpreting HTML or something else interpreting WSDL. No, there are many potential examples of other runtime interpreters. I think a good example is a "workflow engine" that interprets workflow descriptions. Let's say a workflow is stored on a server somewhere. The engine GET's a description of the workflow. Let's say the representation is a collection of RDF triples, some of which describe the orchestration of the workflow. Others describe the procedures being orchestrated, and still others may describe some of the work-in-progress.

The workflow engine, like the browser, is a runtime interpreter of state representations. The browser interprets HTML pages. The engine interprets workflows. The browser understands HTML. The engine understands the orchestration triples. When a procedure is encountered the engine interprets that by invoking the procedure at the given location (or perhaps just abstractly "on the grid") with the given work-in-progress triples as parameters of the procedure.

The RDF triples are runtime state representation, analogous to HTML. The workflow engine is the runtime interpreter, analogous to the browser. An infinite variety of runtime interpreters is imagineable. Mapping engines to interpret locations, ledgers to interpret sequences of transactions, purchasing agents to interpret items for sale.

So are there an infinite variety of state representations. The interpreters will vary by purpose, but their interfaces should be fairly constrained (i.e. RESTful). The state representations will be more broadly useful if they too are somewhat constrained, i.e. if your restful interpreter and mine can understand some of the same state then they can cooperate. This is the idea behind these interpreters sharing partial ontologies or even being able to translate parts of one to another.

Meanwhile Mark Baker quotes Hugh Winkler and then notes...

"When you sit down to write a description language for REST services (a IDL or WSDL for REST), you discover that doing so is unnecessary." Absolutely. The application state machine needs describing (at runtime), not the services (at design time).
The web is a dynamic, distributed runtime. We need to act like language designers and we need to understand dynamic languages.

Monday, February 28, 2005

Classic Rock

Paul Beard uses The Doors as his canary. Tim Bray uses Pink Floyd's The Wall.

Those both work for me. We have (at least?) three Classic Rock radio stations in my area, so I can bounce around those to avoid commercials as well as worn-out music (and beyond into jazz, community radio, progressive politics, sports, etc.)

The best station though has the weakest signal. Two of the stations are here in Portland. The best one comes out of Corvalis where I suppose there is less commercial pressure, or maybe they're just not owned by a conglomerate with a corporate play list.

In fact the Corvalis station, KLOO-FM, reminds me a lot of early 1970's album-oriented stations that don't just play the "hits". They play the songs they want, wherever the song shows up on the album.

Me too and eight-track tapes

Sam Ruby writes...

I'm old enough to remember when relational databases were controversial.
Me too. Sometime talking about the computer industry in the 21st century feels like talking about the iPod vs. eight-track tapes with my kids. (Not to mention reel-to-reel. Remember those?)

Commonality and Variation

I comment on Ted Neward's observations...

SOA as just another paradigm for commonality and variation... just so, even more generally. SOA is a new term, but people were arguing RPC vs. asynchronous message passing 20 years ago, not just in the labs but in production.

I used Apollo Domain workstations and their Aegis OS at Boeing and Mentor Graphics. In the late 1980's I was in discussions about their built-in distributed OS and mailbox channels vs. the emerging broader standards for RPC. People were arguing about RPC parameters vs. sending ASN.1 data structures (i.e. flexible trees of property/value pairs). Not much new in this SOA world but the terms and new standards which look a good bit like some of the older ones!

Sunday, February 27, 2005

QOTD

"Intuition leads scientists astray every time."

A Secure Scheme-based OS

When I read this...

  • A type-safe abstract instruction set (MSIL) as the only system binary interface.
  • A unified extension mechanism for applications and the OS.
  • A strong process isolation architecture.
  • A ubiquitous metadata infrastructure to describes code, data, and communication.
(via this), I think of this. Obviously one has a large, ambitious team and the other represents work by a few people in a more narrow area. But a comparative analysis where they overlap would be worth reading.

Tuesday, February 22, 2005

What Engineers Do

Wayne Allen writes...

What is it that we are envious of from the "other" engineering disciplines?
I think we envy the respect and prestige more than anything else. The nature of software is different though. We have to build software worthy of respect, and it's very easy to build software that is not. We have unprecendented freedom, but...

Chui Tey writes in a comment...

I don't think the software that runs a satellite or one that powers weaponry would be written any less formally than the effort involved with engineering a bridge. Even at these lofty levels, there are elements of craft at the design level, one which comes from experience, and not one that comes from formal learning.
I think we have more freedom to ignore useful formalisms. Part of the challenge is to understand our formal tools and to push them into new capabilities. Test-first programming is an example of a formal tool not widely understood today. Model checking concurrent systems is an example of a current push into new capabilities.

Generally speaking though I think it is the softer communication issues among a development team that typically leads to failure.

More on common language runtimes

Ian Bicking from comments...

You mean, tried it like Guile? That was the whole premise of Guile, that you could translate other languages into Scheme. They never even got as far as translating elisp (which should have been the easy part) so that they could move Emacs to Scheme. That might not really be fair -- honestly, I don't know if anyone cared enough to try, Guile was born of a flame and never had a real champion...
I did not know that was a goal. I've neither tried Guile nor even looked at it. Sounds like more of an organizational thing than a technical issue. The history of Lisp is full of people writing compatibilities to move their code from one (usually older) Lisp system to another. This ultimately led to Common Lisp to avoid doing this so much.
Someone also tried translating Python to PLT Scheme, and they ended up giving up and just embedding Python in the Scheme interpreter...

Guile was crappy to debug Scheme in, but it offered absolutely nothing for any other language built on top of it. Can you annotate your Scheme source with information that allows you to reconstruct the native language environment when there's an error? Many languages deal poorly with incorrect programs, but Scheme implementations tend to be particularly bad, as is any implementation that comes out of an academic background (rather than being designed by a programmer that actually wants to *do* things with their implementation).

Gambit is a good choice because of its C interface, compiler to C, and good debugging capability. Again I am shooting from the hip, but for annotating Scheme source with information for reconstructing the source language information, the nice thing about this is it is Scheme and you can define all kinds of "meta-data" that does something or does nothing execution-wise, but just keeps information around (or eliminates it when desired). Everything is a list, remember. 8^) Just define syntax and/or structure that keeps the information you want, e.g. source text spans for highlighting an expression in a debugger or whatever. Seriously for non-Lisp programmers: everything is not a list. Scheme has "records" ("structs" in C), objects, vectors, etc. I would try defining records for the "meta-data" and the Scheme code would include references to these records.
And that doesn't even deal with the object mismatch issues. You don't actually have to resolve those issues if you just want to take advantage of the performance of the underlying implementation, but if you want to leverage it for interlanguage communication, translating it all to Scheme doesn't actually accomplish a whole lot.
I personally would not want to try reconciling object models too much. I would have each language keep its own definitions and see how easily the translation to Scheme data can support those languages. I would define some kind of interchange but that would not have to be too elaborate. Maybe start with YAML and leave it at that.
I'm highly sceptical of any academic projects, as I they tend to be mismotivated.
Yes, this is just a thought experiment for me. Like the Python and PLT Scheme observation, it may simply be unnecessary when the original language implementations can simply communicate with each other well enough.

The one time I could see attempting something like this would be when defining a new language from scratch. Lisp has always been a good vehicle for experimenting with new languages. They've tended to be more academic and less production too, but something like Gambit for performance is intriguing.

Craftiness

My response to a comment on Wayne Allen's blog...

True, craftiness appeals to many developers. But what is an example of cut and dry standard bits that don't involve craftiness?

Developing TV's? Cars? There is a craftiness to each of these. But less so. And that is where the communication comes into play with the many more informalities. And it is not just color or layout... it's also "What does a user want to do with this purchase order?" There are formal things to do with it, but also informal.

I think software is informal all the way down to the bits on the wire. Only then does it become informal. TV's and cars stay pretty much the same with inflection points here and there (e.g. Tivo, HDTV's, hybrid cars).

Factory, Engineering, Craft, or What?

As James Robertson points out, there are reasons to favor the Software as a Craft metaphor over the Software as a Factory metaphor. But he writes "software is still a craft" (emphasis mine).

That's almost an apology. I'm not sure how intentional his words align with my interpretation, but the notion is commonly expressed, as if someday it won't be a craft but for now it is. Usually the notion is that someday software will be more like "real engineering".

I've taken another view on these metaphors. Let's forget about factories because 10 seconds of thought informs us this does not fit well at all. So the candidates seem to be "craft" or "engineering".

My view is there are things software developers can learn from various kinds of engineers. Maybe there is something to be learned from legal engineering certification processes. But the lack of doing so is not what makes software development seem craft-like.

I think the "informality" of software makes it feel craft-like. If only we had more formalisms. Could be, but we'll always have "informalities". Every engineering effort, and every creative effort in general, involves many informal conversations.

The difference is perhaps software depends more on informal conversations than do many of the traditional engineering disciplines. The requirements in those disciplines are more formal. Most of software development is really requirements development. The interpretation of formal requirements is most easily expressed in software as tests and code that (correctly one hopes) runs those tests.

I think the key difference between software development and traditional engineering disciplines is not primarily the lack of discipline. Rather it is the inherent predominance of informal conversation and that software development fails mostly due to lack of communication. There is room to improve our formalisms for sure. But those improvements will not replace the focus on informal conversation the way standards and formalisms have in traditional engineering disciplines.

Those software development improvements have to support informal conversation. That's why the agile approaches have been successful... when they have improved communication for a specific team, they have improved the results without any new technology or formalisms. Of course some of that communication is in the form of "knowledge transfer" of how to use the available formal tools better. But in the aggregate it is *all* sorts of communication among the whole team that has made agile approaches successful. And when they have not been successful, in my experience it is not from failing to use a formalism well, it is failure to communicate well.

Monday, February 21, 2005

I'm a Broken Record

Update: Luke Gorrie comments...

Can you point me towards any examples that have gone "all the way" with a production language implementation based on translation to Scheme? The approach looks really appealing but I'm becoming skeptical of it.
I don't know. Kelsey went far enough to get a PhD. Feeley (with Erlang to Scheme) went far enough to "prove" the concept. Neither could be considered close to production worthy. The closest thing I can cite would be the compilers for Fortran, Ada, Pascal, C, and Prolog for the Lisp Machine. I'm not sure if they compiled to Lisp or to the Lisp Machine assembly language (which could be seen as a kind of Lisp as much or more than a typical "machine" language.)

I guess the point is not that this is proven, but that today, in 2005, why has it not been explored? People are still beginning VM projects left and right in the 1970's approach. Where does that leave us? Why not try something else, at a higher level, to *see* if it works?

End Update

As per James Robertson, Sriram Krishnan and some folks are building a new VM. It sounds ambitious and two minutes of looking around did not clarify for me why they want to build something from scratch. So rather than suggest they shouldn't, I'll try to be more positive and suggest some reading material for someone interested in these things, then speculate on what I'd do, then admit I have no intention of doing such a thing myself but you might listen to me anyway. Of course I think these ideas are worth considering, unless you *really* want to work on the lower level bits.

Right now, we're looking to copy from existing VMs as much as we can since we really don't have time to design a lot of stuff. This doesn't mean that we don't want to innovate - just that we don't want to reinvent every wheel. I'm personally looking forward to figuring out how to implement continuations inside the VM itself.
You could do worse than to look at the source code for Gambit Scheme and read the 20+ years of technical reports on compiling Scheme. By Sriram's second post, it looks like he is on this trail...
Everything worth inventing has been invented by the Lisp guys 2 decades ago. People like Guy Steele have done some really cool work
I guess if I wanted to work on a language project it would go more like this... start with the implementation of Gambit Scheme because you probably won't do better with less than 2-5 years of research and development. That's probably optimistic, based on the fact that Gambit has a decade or so of concentrated effort from a very bright person, and there's decades of work and discussions that went into Marc Feeley's own thought processes. You'd better talk with those guys because you'll be recreating their mistakes at best.

Then I'd build the translators for the languages I want to run to compile from source to Scheme. Along the way I'd do something interesting to demonstrate the payoff of using what's been done so well already: e.g. I might write translators for partial definitions of a couple languages , perhaps subsets of Smalltalk, Python, and Ruby, and then combine Scheme, Smalltalk, Python, and Ruby in a simple continuation-based modal web server based on Chris Double's tutorial.

The would demonstrate a better way of programming web applications on a well-designed kernel, supporting multiple popular languages. It would also demonstrate the value of continutations in languages that do not have them, e.g. Python (other than Stackless, I think). Pehaps others would want to add to the language fidelity. Another benefit of this approach then is that those folks don't have to understand my VM design, or track its quality, or track its design changes. All they need is to understand Scheme and write a translator from their language to Scheme, or enhance one of the initial prototypes.

GNU Smalltalk is fairly simple... a simple initial translator to Scheme does not seem too hard. I'm not sure what starting points to use for Python or Ruby. But I'm not proposing to do this... only suggest it to someone. I think it would be useful but it's not high on my personal list.

Just some thoughts if there's a Masters student looking for an interesting project.

Shortness

Jim Weirich writes about web apps, Ta Da, and Ruby on Rails...

Ta-Da lists uses XMLHttpRequest to interact dynamically with the host. Beautiful.

And to top it off, it is a Ruby-on-Rails application. Written in 579 lines of Ruby code, that’s less than the size of the XML config files used in many J2EE applications.

And John Wiseman writes about Groovy, Common Lisp, and the shortness of code for an RSS reader...
I had forgotten about when I said that the only way someone would be able to compete with the Groovy app was to integrate with Java or Cocoa, or use CLIM: He created a webapp and generated HTML.
It took me about 3 hours to write. The initial quick hack version took only about an hour and was about 120 lines, but it was not as nice as this one :).
The final version of the code, at about 200 lines, looks pretty good and wouldn't be hard to turn into a desktop GUI app.
The shortness is due to Ruby, Lisp, (or Python or Smalltalk or...) being able to hide any kind of functionality behind a few simple lines of code. We should expect these languages to provide roughly the same amount of abbreviation vs. more elaborate notations.

Maybe if you like writing code these languages aren't for you after all. 8^)

Sunday, February 20, 2005

WTF? Solved: burnatonce

Update: The winner is burnatonce. I downloaded the software and had the CD burned in less than 1/2 hour. I got my refund from the 24-hour company and will apply it as a donation to burnatonce.

Not sure why Microsoft doesn't make their CD burner more easily available to XP users than to download a 12MB Windows Server 2003 package, while suggesting XP users download some guy's freeware that doesn't work. End of update

OK. I want to burn an ISO image onto a CD using Windows XP. The information from Microsoft says they don't have that capability, but to try some guy's free (beta) software! Thanks a lot. Glad my money's being put to good use up there in Redmond.

Hey, I've got an idea. Maybe I should just run some guy's free software from the ground up and skip this whole Windows thing. But OK, I install this guy's free software. But when I burn the CD an error immediately pops up... error code 1800183298837 or something. This guy must have worked at Microsoft recently. No wonder they recommend his stuff.

Then I try Nero Buring ROM. (Ha! Ha! I get it.) Problem is the software sucks so bad out the user interface that I want nothing more than to burn the Nero software itself.

Next I try MagicISO. Installs quick. Simple interface. BAM! The trial cannot burn an ISO greater than 300MB. Thanks. Seems useful enough that I decide to spend the $30 USD right then and there. The order process goes OK.

I get the email confirming my purchase. Great. But there is no key to register the software in the email. And there is no URL in the email to get a non-trial version.

Let's actually read the email.

Your order will be fulfilled directly by company that develops the software. Orders are generally fulfilled very quickly, however, please allow up to 24 hours.
%@($#^!& What is this? A 24-hour turn-around for an electronic purchase? (I chose not to spend the extra $10 USD to get a CD!)

I guess this time tomorrow I will be burning an ISO image on a CD.

With any luck.

Saturday, February 19, 2005

Build Relationships

I guess it is Extreme Programming Day here at Making It Stick.

Kent Beck writes about planning...

We deliver functionality but we build relationships. Planning is more about building relationships than it is about delivering functionality.
I teach a "whole team" Agile/XP course a half dozen times a year. I emphasize values a much as practices. Communication is the value at the top of the list. We also spend a significant bit of time discussing how to adopt XP. My first (and often repeated) message is, if you can only take one thing out of this course then take the benefits of "clear communication with your whole team" into whatever practices you do choose.

Not only is communication the most important value it is also the easiest thing to adopt as an individual under any circumstances. Build relationships.

Slowing Down

Ron Jeffries on the pace and stress of software development...

If you're feeling under the gun, it might be time to slow down.
Amazingly counter-intuitive advice is found throughout Extreme Programming practices. I have *never* seen continued pressure and stress succeed in software development. On the other hand more than once I have seen big improvements when teams are able to step back, breath, make a couple of observations, and move forward gradually. Before long the team is working better than ever.

Courage and Trust in Software Development

Bill de hOra writes...

While refactoring is important for codebases that are expected to provide a product dynasty rather than a legacy mess, it's often devalued as mere tinkering by those removed from source code, as it doesn't provide new functionality - it can be very difficult to explain to a non-expert why not adding, or even delaying features now, will help with delivery of features later.
I think there are several ways to approach this devaluation. One is, do things in small pieces whenever possible. A little refactoring following a little vlaue adding is hardly noticeable.

A frequent question I get in the face of this kind of devaluing is, "Should we just do X and not tell them?" My sense is that sometimes may be advantageous when adopting a practice that has been unduly questioned. But my advice is not to make a habit of this. An important goal is to build an effective whole team, and deception in any significant, ongoing, way cannot be effective in the long run.

There is a more positive approach to this kind of behavior. That is to revisit the roles and responsibilities of developers and other stakeholders. In this case, developers have the responsibility to improve the design when they believe they'll get better at adding value in the longer run. Stakeholders having the courage to trust their developers is as important as those developers having the courage to admit they need to go through a significant refactoring for some reason.

Most software development practices over the last several decades have not brought courage and trust into the equation. Making these values part of the discussion is a clear advantage to agile methods and Extreme Programming. Scary, but better to be encouraged to courageously dive into the depths of what will haunt you anyway, even if ignored.

Friday, February 18, 2005

That's It

Bill de hOra...

We can see the market looking at 3 things to provide value in software solutions:
  1. Simple protocols and formats
  2. Open source infrastructure
  3. Agile methodologies
All of these are disruptive.

Wednesday, February 16, 2005

Skiplists in C# and Smalltalk

This on data structures recently from MSDN...

Skip lists are an ingenious data structure that turns a linked list into a data structure that offers the same running time as the more complex self-balancing tree data structures... In the latter part of the article, we'll be building a skip list class in C#, which can be downloaded.
Cool.

I recently had a use for a skip list in Smalltalk and could not find code I wrote a significant number of years ago. So I got out the trusty skiplist cookbook.

Fortunately I did not get far before discovering that skip lists are available "out of the box" in Squeak.

Tuesday, February 15, 2005

New Functional Geometry

Bill Clementson references a functional programming book chapter on functional geometry. (Part of a really interesting book from the early 1980's still worth reading.)

As it turns out the functional geometry presentation has been updated.

The Future of SOAP

James Governor writes...

One big question is why haven't IBM and Microsoft responded? The obvious answer is vested interest. When you have "bet the company" on a technology stack its kind of a drag to have to respond to something else. Its interesting that in a week when the bug guys, including Gartner, have trumpeted the arrival of UDDI 3.0, the world is quietly getting on with more interesting projects.

Smalltalk Evolution

The question is raised, how does Smalltalk evolve?

My answer is "very little". Smalltalk is not perfect, but is high up on the list of near-perfect languages. Any radical changes are better off being put into a new language. Otherwise the change can be put into one of the open source Smalltalk implementations and adopted ad hoc. That's your choice and right. If the change succeeds wildly the community will adopt it for you.

Meanwhile there is controversy over the leadership of Squeak. I don't know the whole story here but this is open source. They seem to be mostly supported and they've stepped up to the task, so good on them. It's not like they should be taking the language in radical directions.

Fork the language under a new name for radical changes. Let Smalltalk be Smalltalk at this point. I think the limitations of other languages lead their communities into a mindset of constantly adding features as if it were a Microsoft Office product.

Monday, February 14, 2005

Less is More

Blaine Buxton makes an often discounted observation...

Removing code means you are simplifying the code and the result is a net gain. So, next time, you're refactoring and deleting code. Don't think of it as deleting, but as gaining code via simplicity.
Blaise Pascal is quoted as saying...
I have made this letter longer than usual, because I lack the time to make it short.

Sunday, February 13, 2005

Shell Scripting

Danny Ayers is looking for a shell script to keep another process alive. I'm sure I won't do better... I do as little shell scripting as possible. Shell programming never seemed aimed at humans.

Everything I've wanted to do manually in a shell script I have done more easily in Emacs or some other interactive programming environment involving Lisp or Smalltalk. For automated tasks its as easy to schedule a Lisp script as easily as bash. The trick in the past was using a small Lisp like XLisp or one that generates small apps like Gambit Scheme. That's still the trick but there are more choices.

Many Lisp implementations these days understand the #! notation to run as a script. Another option is to use scsh, the Scheme Shell.

Saturday, February 12, 2005

Between a Rock and a Hard Place

Tim Brookins writes...

In case you've been living under a rock, Longhorn is platform for the next decade...

Software developers live to ship code. So delaying the first release of MBF is painful. However, as a Software Architect, I am absolutely convinced that this was the right choice. Shipping part of MBF in Whidbey and part in Longhorn would have created a system which spans two technology eras.

Interesting. There are several potential messages in this statement but I am not sure how a customer deciphers which should be heeded.

Friday, February 11, 2005

Objects and Processes

Ian Bicking on objects and processes (when processes are done right)...

That's when I thought about Erlang. Instead of objects, Erland has processes, and you send messages between processes. It seems obvious, but when I'd looked at Erlang before the parallel hadn't occurred to me. In that light Erlang processes make much more sense to me.
Something about Erlang design... if you need state, like an "object" would, then put it in its own process. Asynchronous messages to update the state and return state information. Like many small "databases" on the order of a table or so running in their own process.

Study the Work of Others

From Harold Carr's talk at the University of Utah...

  • No literature search in industry.
  • No encouragement for deep knowledge (want "code monkeys")
  • To climb ladder encouraged to manage or "architect" versus doing "the" work

  • Great painters and writers don't delegate
  • They continue to do the work themselves
  • And they continue to study the works of others

Not long after writing this, I come across an item from James Robertson with more ever-present evidence of this sad observation.

Adventure Ahead

Robert X. Cringely writes...

Right now, there is in the U.S. venture capital community about $25 billion that remains univested from funds that will end their lifespans in the next 12-18 months. If the VCs return those funds to investors they'll also have to return $3 billion in already-spent management fees. Alternatively, they can invest the money -- even if they invest it in bad deals -- and NOT have to cough-up that $3 billion.

...so get ready for the most furious venture investing cycle in history.

Thursday, February 10, 2005

Inexplicable: Truth Held Hostage

Where's the outrage over the recent 9/11 disclosure?

In April last year, President Bush said, "Had I any inkling whatsoever that the people were going to fly airplanes into buildings, we would have moved heaven and earth to save the country. ..." The 9/11 commission report apparently found that there were indeed such inklings, which should have "raised alarms about the growing terrorist threat to civil aviation throughout the 1990s and into the new century."

We're left with a pretty good inkling as to why the president moved heaven and earth to keep it quiet before the election.

And reading about Mark Dayton...
Also adding to his vulnerability, Dayton recently delivered a stinging denunciation against the confirmation of now-Secretary of State Condoleeza Rice.
I should think Rice would be the vulnerable one. Some National Security Advisor!

Speaking in Objects vs. "Code Complete"

I was listening to a presenter in a recorded session today refer to their project being "code complete". I did not expect any to refer to that term these days.

Coding never made sense to me as a milestone. I was on one of the first death march C++ projects ever, beginning in 1989. The previous couple of years were spent primarily developing in Lisp. Even with CFront, no debuggers, mangled names... or maybe especially because of these things, my preferred development style was to be unambitious about the results, and to work in small steps.

As a whole hubris had overcome the team. C++ would enable us to rule the world, the sooner the better. The intuition was to spend more time thinking and then coding. Compiling, etc. took too long, so should be avoided.

The problem is that "thinking in objects" is not nearly as productive as "speaking in objects". When you speak in objects, you have a dialog. You speak your intent into the editor and the objects you create respond right back, the sooner the better.

Today Phil Windley writes about a couple of projects still on that old beaten path. So that's three projects in one day I've come across.

I think Ward Cunningham said...

It's all talk until the tests run.

Ruby's Postulate

From a talk by Sam Ruby...

The accuracy of metadata is inversely proportional to the square of the distance between the data and the metadata.

Wednesday, February 09, 2005

What She Said

Kimbly...

I have more to say, about how democrats are a pathetic excuse for a progressive party.
Meanwhile, we should get on to the serious business at hand... starting with this guy...

Language Evolution

Philip Wadler's humorous take on language evolution. (pdf) Via Finding Lisp.

Not Getting It Any Way

Via Cheese Bikini, too bad Nintendo apparently doesn't get it. The DS is a nice device.

This is the sort of rich, simple innovation that I hoped would emerge with the wi-fi enabled Nintendo DS portable video game system. But Nintendo seems to have locked down DS development, limiting it to internal and professional developers. Such professionals have years of experience and training in building traditional games. This background cripples their ability to innovate, to see beyond the constraints of traditional game platforms.

Nintendo, learn from eBay and Google and Amazon: let customers and outsiders build value for you. Open your platform and let it thrive.

Software Factories

Clicking through from James Robertson's item about Smalltalk and C#(?), another item refers to Software Factories.

I will wager any system using a factory metaphor for software development will either not get off the ground or hover low to the ground for some time until they shift the metaphor to something lighter weight. Like balloons.


You're Getting It Our Way

I think Bill Venner in his item on static and dynamic is trying too hard to separate language and culture.

Python supports this multi-valued return technique better in its syntax than Java, but I realized that the availability of syntax isn't the main reason I do it in Python. The main reason is that's the way it's usually done in Python. By contrast, that's not the way it's usually done in Java. The cultures are different. The culture that guided the design of a language influences my attitudes and mindset when I use the language. The Java culture encourages me to build solid bricks...
I don't think you can untangle the culture and the language, even the syntax. Python the language was influenced by Lisp and Smalltalk. Those languages were developed by, and developed the dynamic culture that surrounds them.

Lisp was created in the late 1950s by people who needed agility more than they needed speed. (Yes, 1950s.) Smalltalk was influenced by Lisp, and Python by each in turn. They began is labs that gave us the earliest work in AI, collaboration, and usability. They were not computing pi or finding the next largest prime number.

This realization got me wondering, to what extent is this perceived increase in productivity with languages such as Python, Ruby, and Smalltalk due to the culture of those communities, and the mindset that the culture engenders in programmers, versus the actual languages themselves? What is the real source of the differences in the static versus dynamic language debate?
A community cannot sustain a specific culture unless the framework supports that culture. Programming languages are the framework that sustains the culture of the community that uses the language. They go hand in hand and nother will change that.

Today, and since the late 1980s, the programming community in general has needed agility for the most part more than we have needed speed. Our languages coming out of the "need for speed" community (C and Pascal, then C++, and now Java, C#) and the cultures that accompany them, have slowly been migrating to be more a culture of agility and less a culture of speed.

Those need for speed languages have features and those cultures have adopted practices that are more like the agile languages developed and used in the AI and collaboration labs in the 1970s. Finally we are seeing the last stages of the transition. Truly dynamic languages are gaining mindshare over the partially dynamic.

Meanwhile good implementations of dynamic languages and the advances of hardware have all but eliminated the speed side of the equation. There are fewer uses than ever for the languages coming out of the speed culture.

Update: A comment on Bill's blog...

Whenever you start to think of some Java problem as a general problem with static type checking, maybe rewrite it in Nice http://nice.sourceforge.net/
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I agree as far as that goes. The newer type systems are "dynamic" even though they represent a somewhat different development model than more traditional dynamic languages. But I don't know Nice and cannot say that it is dynamic or merely "partially dynamic", esp. if it is just a precompiler for Java. (Someone will correct me so I won't even google it.)

Being dynamic or agile is more than just having an explicit type system, or having a bad type system vs. a good one. For example, are relatively heavy mechanisms like "class loaders" needed?

Imagine That

From MSDN .Net Architecture Center...

The file has been the central container of work in software development for over thirty years. All of a project's structure and logic is ultimately reduced down to files and directories. The tools that surround software development are built around this concept, too. This article explores the concept of file structure, and contrasts it with an emerging view of Model Driven Architecture...

It seems clear that the file is a relic that has outlived its usefulness for software development...

The modern development environment has not yet fully caught up to the object-oriented shift. All of the tools still rely on a file to be the container of source code. While some contain modeling capabilities as well, the models exist as different entities than the file and its code.

Maybe some tools. Not all tools.

The article seems to conflate two issues that could benefit from being addressed independently:

  • Files
  • Models
By the end of the article I did not really learn anything new about the next generation of tools in Microsoft's Dynamic Systems Initiative, which seemed to be the intent.

Tuesday, February 08, 2005

TDD: Test-Driven Demo?

Perhaps preparation for a demo should be treated as preparing any kind of release for an Extreme Programming project...

  • Prioritize the stories.
  • Write the story tests.
  • Break stories into tasks.
  • Program test-first, writing the task tests and completing the tasks.
  • Run the story tests as the tasks are completed.
  • Any stories not completed by demo day will not be in the demo.
  • The stories are prioritized up front but can change as marketing needs change before the demo day.
If the person doing the demo sticks to the script there should be a good chance the demo won't crash.

When to Generate

Xach Beane is dissing maps.google.com...

Google Maps is essentially a large JavaScript application. Great hackers have an almost instinctual aversion to JavaScript. Google is betting its future on something a tasteful programmer's radar rejects.
I don't think JavaScript is that bad, but I've never been accused of being a great hacker. JavaScript has a few things going for it...
  • It is fairly simple and regular. Not a lot of obscure corners.
  • It is ubiquitous and familiar.
  • Most of the interesting uses for it in the browser can be written once or generated on the server!

Monday, February 07, 2005

Cygwin Heaven

I hadn't used Cygwin in some time. So nice. I found a tip for setting the TERM to rxvt which makes applications like emacs display well.

Gambit-C 4 beta 12 builds fine. The 'make check' test fails, maybe due to some CR-LF text/binary mode setting I need to consider. When the tests are diff'd ignoring whitespace they work fine. The tests for the C interface and dynamic loading need to be looked at. But the resulting executables seem fine so far.

Now I need to try the emacs mode for gambit.

Sunday, February 06, 2005

Theory: More than the Sum of Some Parts

More evidence a theory is more than the sum of some parts.

In Need of a Theory?

The notion of establishing a "metaphor" in Extreme Programming is similar to programming as "building a theory" as proposed by Peter Naur.

Reading how "Microsoft officials have characterized SharePoint as 'the killer app for XML'", I am looking for a theory to emerge in the way that perhaps continuations are beginning to form a theory around web server programs and s-expressions form a theory around manipulating XML.

SharePoint is a larger concept than continuations or s-expressions. So I would expect a larger theory, but a theory nonetheless, to associate SharePoint and XML conceptually. I did not see one emerge in this coverage of Bill Gates' keynote at a Microsoft Office conference.

Gates told keynote attendees to expect Microsoft to more tightly integrate SharePoint with other Microsoft technologies and point products, going forward. He said to expect SharePoint and Active Server Pages (ASP) to "become closer," and SharePoint and SQL Server to become more entwined, as well.

Gates discussed Microsoft's quest for unified storage of all types of data, ranging from files to e-mail and emphasized that SQL Server would be the ultimate repository for storing this type of data.

As "SharePoint evolves up on the server and WinFS evolves down to the client," Microsoft will be able to realize its unified storage goal, Gates told attendees.

Gates is attempting to associate a number of disjoint concepts in this quote. This approach is something I would expect of a salesman, rather than a Chief Software Architect. An architect should be a "theory builder". I would have trouble buying into this stated direction without a better theory, or even any theory at all.

Of course this opinion could be dismissed as just more Microsoft bashing from the likes of me. But think about it, and tell me the theory that is holding all this together. Maybe I am just missing the point. Microsoft provides the dominant architectures in my computing world. I have a vested interest in them making my life easier, and so I have the desire to point out where I think they're missing the mark.

From this, I think they're missing a theory that could propel their success for another decade. As it is, I suspect they're cobbling pieces together and I am asked to take their Word for it that there is a "there" there where there should be a theory.

Template-Based Programming

The last C++ program I wrote was long before templates became part of the language. Ted Neward writes...

There's a tremendous amount of power in template-based languages.
I have no idea what this implies for C++. I can agree that it's true for Lisp though.

Programming macros in Lisp perhaps has at least something in common with programming templates in C++. Where you go from there is up to you. I hope never to write another line of C++ even with templates.

Defending Applications

Phil Windley also writes about defending an application from OS attacks by running on multiple operating systems. An interesting idea that could be taking one or two steps further...

Better XML Scripting

Phil Windley writes...

I've written programs that use XML in Java, Perl, Python, XSLT, and now Scheme. Scheme has been the easiest. I think the reason is that with s-expressions, XML is essentially a native data type in Scheme. That's an incredibly powerful idea.

The Soul of a *New* Machine?

Ted Leung writes about a reinventing of capitalism to enhance its positive social effects.

I happen to be reading an arguably related book of essays, and poetry of all things. Poetry does not have the same cultural reception here in the US as it does in other parts of the world. This book, ("The Heart Aroused", by David Whyte, who I knew briefly 18 years ago when I lived on Whidbey Island just north of Ted's Bainbridge Island) addresses the problems of capitalism as they occur in our everyday work life.

Here is part of David Whyte's essay on Beowulf...

Business and politics profess to be hardheaded, but how many businesses, and even countries, have been ruined through decisions that were ostensibly hardheaded but which had more to do with the relutance of those in charge to face fears or vulnerabilities?

This reluctance to enter the deeper waters of the psyche is not confined to modern participants of corporate life. Fifteen hundred years ago in the Old English poem Beowulf, an anonymous bardic author confronted his listeners with a frightening image of this inner lake. His listeners were almost certainly rough warriors used to getting their hands dirty. He found them equally shy of that dark water.

Beowulf is a masculine story of descent into the waters of the unconscious, but where the restoration of a profound inner feminine power is essential to his survival. In that context it is a compelling story for both women and men working in a masculine workplace sorely in need of a commensurate balancing power. In a corporate culture still dominated by the image of the warrior archetype, Beowulf's plunge into the waters of the unconscious seems to be equally instructive for both sexes.

The early English teller of Beowulf asked his listeners to drop beneath the surface of their daily existence, where the rational mind continually prays for dry feet. Since that time the physical details of life may have changed. The elemental motifs have not.

Decentralization

John Robb writes...

My future opportunity, and yours, is being diminished by a state that doesn't value decentralized energy and prefers to spend its coin on military power.
The sad irony is these concerns and strategies were being addressed in the 1970's at least. I remember reading a pamphlet in the early 1980's called "The Indefensible Society" about this idea. As it turns out the web has an excerpt from that pamphlet.
Because moving in the direction of decentralization and the development of planetary villages is different from the direction our society has been heading during the past century or so, it is likely to be dismissed at first glance as impractical and utopian. Yet in reality it is eminently practical and well within our means as a society. And not only is it appealing and workable at a human level, it also can provide creative and effective solutions to problems that presently seem both unsolvable and out of control, such as the arms race.
Of course the original 20th century arms race is over. (On the other hand the US is spending $1 billion USD per week on Iraq.) The problem now is at least as dangerous as the arms race.

Saturday, February 05, 2005

Cooler than That

Web shopping in particular, and web user interfaces in general, just got a lot cooler. Clearly, 2005 is now officially the year of the rich thin client.

This is really inspiring work (try it), and the contact information shows Portland, Oregon. Anyone know who is behind this?

(Via Mark Baker)

Lessons Not Learned (Yet?)

Avi Bryant writes...

In Smalltalk, however, the only thing that's in C is a tiny virtual machine that understands a very simple set of bytecodes - it knows about pushing and popping objects from the stack, accessing indexed slots, blocks, and method dispatch. What it doesn't know anything about is the language syntax, standard library, compiler, debugger, profiler, thread scheduler, exception system, and so on, and so on - all of these things are implemented in Smalltalk.

[Smalltalk] doesn't support continuations and you want to add them? No problem; 10 lines of [Smalltalk] code and you're there.

...clearly you could implement the Ruby language with a Smalltalk-style VM (hopefully one with a Smalltalk-style JIT as well, which would bring a 20x or so speed increase to the current Ruby interpreter). But really what I'm talking about is a philosophical difference, not a technical one: to Smalltalkers, it's essential that as much of a system as possible be implemented in Smalltalk, whereas this simply isn't a priority for the scripting language community, and it's the priorities rather than the individual implementations that draw me to Smalltalk.

Schememonster

Beware.

Via Blaine Buxton

Modern Software Architecture

Gordon Weakliem writes...

Mozilla is still a C++ app though, and seems to be very stable. Architecturally, it seems to be built around JavaScript and XUL though. It's almost like a VM architecture in that respect. I've been messing with Mozilla Extensions lately, and though it's not the greatest development environment ever, it's very easy to write code for once you get your bearings. The XUL architecture seems to extend very far down into the browser, with most of the browser implemented in XUL and script. Again, it seems like an underlying VM is a prerequisite for a modern software architecture.
Which is ironic given not more than ten years ago the programmers using this architecture were fighting heated arguments about the very idea.

Friday, January 28, 2005

Lisp: an XML scripting language?

I guess if I had to sell someone on Lisp or Scheme today, I might describe it like this:

"Lisp is an XML scripting language."

More sexpr in Utah

Phil Windley is connecting language concepts, Scheme, and XML in his BYU programming language concepts course.

He has a simple excercise that makes the connection. The next step would be to blow their minds with SSAX.

Update: Phil Windley has a page for his students for running SSAX. To gauge how similar Lisp is to XML, how natural the mapping, the SSAX translation of Phil's original classroom example is identical except SSAX wraps Phil's translation in a list to indicate that is the top of the document...
(*TOP* (phil's data))

Naturally Dull

"Naturally dull, I’ve forgotten Zen activities"
- Isshi Bunshu (1608-1646)

Thursday, January 27, 2005

Testing Interfaces

Another blog item on testing.

This one asks whether the tests themselves should alter the interface of what's being tested. i.e. should the test have a back door for peeking into the black box.

My opinion is, emphatically, no. Not for the kinds of tests created while test-first programming.

An impulse to check on the internal state of an object while test-first programming is an indication of one or two things:

  • The test is being perceived too much as "testing" and not enough as "designing".
  • The object itself is probably too complex. Fix the design.

A Future so Bright?

Um...

Avid sailor Craig Venter has trawled for microbes in the Sargasso Sea and discovered more than a million new genes and 1,800 new species. Among them are organisms that thrive on carbon dioxide. Venter hopes to re-engineer some of these unique microbes genetically, into "designed species" that may reduce environmental CO2 levels, as well as provide new foods and energy sources. "Biology can do much more sophisticated chemistry than the best chemists," says Venter.
Hey, I suspect biology can do much more sophisticated *biology* than the best biologists as well!

I'm not sure I want people tinkering with CO2 consuming microbes any more than I want us putting fossil carbon into the atmosphere in the first place.

Test-First Programming

Frank Sommers writes...

I find myself violating this tenet of XP very often. I do test all my code, but often only after I've already written that code. Why does this one XP rule seem so out of place to me? ...

I like to think of refactoring and testing as editing. When writing an article, most writers first create an outline, then write the content, typically in a few sittings, and without regard to mistakes, typos, sentence structure, etc. Only then does an author spend most of his time on editing, fine-tuning, and polishing the article.

I think this seems out of place when "testing" is perceived to be a testing activity rather than a design activity. Rather than not testing first, try taking on a new perception of what it means to "test" software.

The way I view test-first programming exhibits the same outline -> content -> polish flow. In my perception, the "outline" is the short list of tests I think I want to write over the next hour or so. This list of tests is just a list of names, each name being some *design* feature that needs to be developed. Each name will show up in the design.

Then the "content" is the expansion of a name on the list into code:

  1. One or a few function calls or message sends.
  2. One or a few assertions about what is true afterwards.
  3. The other code needed to setup the calls, implement the assertions, and teardown.
  4. Then when this content breaks, the test framework tells me what's wrong.
  5. The rest of the content is missing... I have to write the code that implements the calls.
  6. When the "test" part of the content does not break, the initial draft is complete.
This content (the calls and assertions) is design information, an expression of a design contract. I am not testing something already conceived. I am in fact conceiving of something, creating something, designing something new: an expression about a system and an assertion about what is true given that expression.

As soon as the content is drafted, immediately I begin to polish that draft, consider how it fits with the other content, and how the content itself could be better expressed through reconsidering the names and parts and assertions.

So I see test-first programming as a way of designing. It happens to be a way of testing as well, which is good because a program has to be tested in ways that an informal text does not.

Wednesday, January 26, 2005

Exactly

A note to Sean McGrath from Steve Jensen in Sean's comment section...

Thanks for plugging Erlang: even if it doesn't end up being heavily adopted, it at least moves people in the right direction.
Exactly. I like what else Steve wrote...
We need to move from using semaphores and monitors to lock global state towards thinking of the world as partially ordered and asynchronous.
Someone asked Joe Armstrong at his Lightweight Languages 2002 presentation what synchronization mechanisms Erlang has. Joe responded, "Two. Send and receive."

Exactly.

Why...

...is Sharepoint the suckiest thing on this planet?

Monday, January 24, 2005

JSON: The Fat-Free Alternative to XML

JSON is the JavaScript Object Notation for writing "smart clients" like GMail in JavaScript without bulky XML messages. JSON-RPC is a simple RPC mechanism like XML-RPC. (Via Slashdot.)

I suppose this could also be based on YAML which is more rich than JSON, yet still not as complex as XML. I've not seen a mapping, in the few minutes I've looked, from JSON to XML, such as what's been defined for YAML.

Sunday, January 23, 2005

Communication

As seen on the XPDX Yahoo group...

Thanks for all the comments... One respondent said XP depends on communication, but I work in a corporation.
I guess that corporation does not "empower" their employees enough.

We Won't Get Fooled Again?

Scott Rosenberg writes...

The Bush inaugural marked the final transition of the Bush-family ideology from old-school conservatism, with its abhorrence of abstract schemes of human perfectibility, to a messianic idealism so divorced from reality it gives even sympathizers like Noonan the willies. Bush's vision of human perfectibility may be shaped by born-again fervor rather than socialist theory, but that difference doesn't make its collision with reality any less dangerous.
and writes...
This speech wasn't just soaring rhetoric. It was a lighter-than-air burst of helium verbiage -- lofty language untethered from the perplexing world we occupy and from the messy events of the last four years, sentences floating off into an empyrean of millennial vagaries.

The world is a simple place to Bush... His "untamed fire" is the cathartic inferno dreamed of by people who are confounded by a world they know is out of their control.

Thank You, Ken Anderson

Thank you, Ken Anderson, for your contributions to JScheme. There have been many times when I needed access to Java functionality but not the Java language per se. JScheme makes that kind of programming pleasant and productive. One of Ken's contributions was the Javadot notation which is a large part of ease of this Scheme/Java integration.

From Tim Hickey, another of JScheme's creators, via Chris Double...

I'm sorry to bring you the very sad news that Ken Anderson, one of the co-developers of JScheme, died last night...

Ken touched many lives and brought many communities together.

Saturday, January 22, 2005

Lisp and Concurrent Programming

Bill Clementson has a huge list of Lisp-related concurrent programming references. And if you haven't looked at Erlang yet, it is a list-based semi-functional language. Too bad it doesn't use Lisp syntax.

Bill refers to Dirk Gerrits, building an Erlang-like concurrency mechanism in Common Lisp. Something like this was done for Python as well, called Candygram.

Also related is the ETOS compiler for Erlang that generates Gambit Scheme, which scales as well as Erlang/OTP.

The mind spins, concurrent thoughts swirling all around.

This and That in Politics

I'm reading this and that near each other in my bloglines. They both alarm me for reasons that are not dissimilar.

PyCon DC 2005: IronPython

I didn't see anything on IronPython at the March conference, but Sam Ruby pointed out the keynote.

Structure and Notation of Computer Programs

Agreed...

We're not so much building on the programming state of the art as continually have each generation of programmers rediscover it.
-Bill de hOra

Thursday, January 20, 2005

OOP Is Much Better in Theory Than in Practice?

Lambda the Ultimate discusses the merit of an article as well as its content. Again against the object.

I think OOP is better in practice than in theory. But then I value practice more than theory.

Guessing from the Terminal

Mountains of wisdom from the Mountain of Worthless Information...

Next time you're in a meeting with folks and somebody asks you how long you think it'll take, be sure to tell them whether this is a "from the terminal" sort of guess, or a "from the ground" sort of guess. The difference? Until you've been-there-done-that, and have something against which to measure their requests (meaning you have some kind of experience with the things in question, ideally having built something like it before), your estimates are likely to be all "from the terminal" guesses, and highly likely to be wildly off base.

Smug Lisp Weenies

John Stephen Jacob Anderson, apparently a SmugLispWeenie if there ever was one, writes...

Python was the subset of Lisp that was understandable by C++ programmers.
Being at least a former SmugLispWeenie myself I am having trouble disagreeing. Which is not to say Python is bad, it just loses in certain significant ways that Lisp does not.

Update based comments:
"outside of the CS department"

Ouch.

I think Lisp is safely outside the CS dept. If we could get it *into* the CS dept. maybe things would improve a bit.

"Listing those significant ways"

Syntax extension, syntax itself, closures, continuations (Scheme in this case), to name the top of my list.

I would also include as a result of these, Lisp is a good vehicle for language experimentation (or just defining new object systems), whereas Python provides a simple object system it is more restricted in where you can take it.

Which is not to say that I would not choose Python over 90% of the industry's languages. I would.

Cairo as well as OpenGL

From "The (Re)Architecture of the X Window System" a progress report on Cairo...

This integration of the familiar PostScript operational model within the native application language environments provides a simple and powerful new tool for graphics application development...

Cairo's rendering algorithms use work done in the 1980's by Guibas, Ramshaw, and Stolfi [GRS83] along with work by John Hobby [Hob85], which has never been exploited in Postscript or in Windows. The implementation is fast, precise, and numerically stable, supports hardware acceleration, and is in advance of commercial systems...

Cairo is in the late stages of development and is being widely adopted in the open source community. It includes the ability to render to Postscript and a PDF back end is planned, which should greatly improve applications' printing support. Work to incorporate Cairo in the Gnome and KDE desktop environments is well underway, as are ports to Windows and Apple's MacIntosh, and it is being used by the Mono project. As with Xft2, Cairo works with all X servers, even those without the Render extension.

Also regarding X and OpenGL...
Using OpenGL as the basis for the X server itself will place X objects such as pixmaps and off-screen window contents inside OpenGL objects allowing applications to use the full OpenGL command set to manipulate them...

Whether the "core" X graphics will require any OpenGL extensions is still somewhat an open question.

In concert with the new compositing extensions, conventional X applications can then be integrated into 3D environments such as Croquet, or Sun's Looking Glass. X application contents can be used as textures and mapped onto any surface desired in those environments.

I think this is huge. (Yes, even huger than Avalon). Turning X, per se, into a legacy window system within a portable, modern vector and 3D graphics environment. Just remember, Don't Fidget With Widgets, Draw!

Where did those OpenGL patents go, again? Oh. Yeah. Now I remember.

Via Miguel de Icaza. (Microsoft must be wetting their pants trying to get de Icaza to sign up with them. I'd like to see the offer sheet.)

From the "What's That Again?" Department

From CNN...

"Poll: Nation split on Bush as uniter or divider"
Well then, apparently we have our answer.

Models for Backwards Navigation

Nice alternative implementation of a continuation-like web mechanism for languages without first-class continuations.

Unwittingly explains the *conceptual* model of continuation-based web servers. Languages with continuations offer a better *programming* model by simplifying the web programmer's *mental* model.

If you are familiar with web programming but unfamiliar with continuations, read this one first to get the concept, then read about continuation-based implementations.

Wiki and Comment Spam

I've not written my own wiki or blog system, and not thought about this problem at all. Given that, what if a form of "email authentication" was used to approve wiki edits and blog comments? (I think I've seen this somewhere but can't get google to remind me where.)

  1. Someone edits a wiki page or adds a comment.
  2. The change is suspended until "authenticated".
  3. At this point the person enters an email address (of some determinably accountable, non-transient nature).
  4. The change or some indication is sent to the email address.
  5. Upon receipt of the response or via an http form in the email, the change is accepted.
  6. In addition to other filtering and governing, the site now also has an email address.

Tuesday, January 18, 2005

Being FIT

Will Stott writes about using FIT via Excel.

Proof Carrying Code

I've only read a surface amount about Proof Carrying Code. In spite of my default stance on types, I am interested in ML and Haskell style type inference. So this book looks interesting, covering both topics and then some.

Via Lambda.

Can You Have It Your Way?

Guido's latest wandering around the world of type checking are disturbingly non-committal. I'd like to see his thinking get back to root causes and work forward to solutions. As it stands he's kind of wandering around the space of semi-solutions to unspecified problems.

Uninteresting and not a good use of my time at this point. If you've read this blog you know I am not interested in types much if at all. But whereever you are on the spectrum you most certainly would benefit from language changes being rooted in clearly outlined problems statements and solution explorations.

Monday, January 17, 2005

Objects are Easy? (Maybe Not)

A comment on Scott Rosenberg's blog post about concurrent programming...

Herb Sutter's analogy to object- oriented programming is completely bogus - OO is a bag of tricks for making it *easier* to write programs (often at the expense of making them a little slower), and especially easier to debug and maintain those programs; parallel programming makes it *harder* to write programs, and dramatically harder to make them correct, debuggable, and maintainable. It's just not going to happen.
First I would argue that programming with objects is not easier. But then the question is easier than what? The commentator does not say.

Objects are a code organization mechanism. As the complexity of a system grows, objects help through organizing the complexity. Progammers can use objects to focus on specific problems without being overwhelmed by uninteresting aspects of the system.

But objects are not easy. However I would agree that concurrency is even more difficult, especially given the languages and tools of the past several decades.

The commentator appears to be making an assumption though that the languages and tools of the past will not improve and there will be no incentive to improve...

As a software engineer with over 20 years experience, including a good deal on highly parallel machines, I can tell you for sure that there is not going to be a revolution in software development. Explicit parallelism is just too difficult to get right in general, and the applications that benefit from it have already been optimized for multi-cpu machines since the 1980's.
This sounds a lot like previous infamous predictions like no one needing more than 640k RAM.

Objects are hard, but they offer better notational organization. Processes are hard too, but they offer better dynamic organization. We just need better notations and tools for processes and someday someone may be writing something like "concurrency is a bag of tricks for making it *easier* to write programs".

The same commentator adds in a subsequent comment...

People don't get smarter, so this problem is not going to be solved no matter how much Intel would like it to be.
The same might have been said about programming sequentially before objects, or even modules and structured procedural improvements. The software industry has gotten smarter, perhaps not as quickly as any of us would like.

Friday, January 14, 2005

The Io Programming Language

A friend has been playing with the language Io. I spent an hour or so with him on it. Very interesting.

Io is small prototype-based programming language. The ideas in Io are mostly inspired by Smalltalk (all values are objects), Self, NewtonScript and Act1 (prototype-based differential inheritance, actors and futures for concurrency), LISP (code is a runtime inspectable/modifiable tree) and Lua (small, embeddable).
The language has an interesting evaluation, reflection, and delegation model. Io has a syntax that does not always require an explicitly denoted receiver for a message. Someone just learning Io can scratch their head once or twice figuring out what's going on.

On the whole though Io is a very simple language with what looks like a simple CPython-like implementation. For programmers looking to understand the "prototypes and delegation" approach to object-oriented programming (as opposed to "classes and inheritance"), then Io seems to be a simple way to dive in deep.

Playing a bit with Io felt a lot like the pre-CLOS days of Lisp in the 1980s when there were a lot of experiments with object systems like ObjVLisp, OakLisp, Loops, etc.

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About Me

Portland, Oregon, United States
I'm usually writing from my favorite location on the planet, the pacific northwest of the u.s. I write for myself only and unless otherwise specified my posts here should not be taken as representing an official position of my employer. Contact me at my gee mail account, username patrickdlogan.