Update:  the link to the article seems to be broken.  Fie!

The Marin Independent Journal published an article about some of the fascinating medical work my Dad and his wife do in San Francisco.  Pretty cool stuff.  The article mentions the trip we took to Disneyland this summer.  Once again, the Internet knows everything.

Sam Ruby is talking about problems with textual data out on the web, or more specifically in the context of RSS, having to do with bad assumptions about character encoding.  As someone who once did a lot of work in localization, it's a subject near and dear to my heart. 

I'm always amazed that still to this day people don't get that there are such a thing as character encoding. 

Sam points out that an upper case A and the Greek Alpha show up in most fonts as the same glyph.  However, they are different code points in Unicode. 

He's moving this idea up the stack to show why there are so many conflicts between HTML/XML/RSS/etc.  The rules for character encoding are different in all those systems and are enforced differently by different tools, which is what causes so many RSS feeds to be badly formed. 

He started the presentation talking about how XML is an "attractive nuisance" with regard to the encoding issue, in that it leads people down the primrose path to thinking all their encoding issues are solved just because XML is supposed to take care of encoding. 

All in all, the issues Sam is talking about are pretty obscure, and appeal mostly to XML wonks, but that doesn't make them any less valid.  The reality is we've all learned to deal with it most of the time, just like we're used to IE fixing up our bad HTML tables.

Just two more days until the Dev Con.  I had a great time both speaking at and attending last year, so I'm looking forward to another exciting time.  Scott and I will be talking about some of the things we're doing at work around XML Schema and using "contract first" coding in a non-Web Services context. 

I hear there are still a few more open seats...

Being a non-CS degree holder (I can tell you all about Chinese vs. Japanese Buddhism though) I've always been a bit intimidated by the idea of parser/compiler building.  Luckily, there's Coco/R.  I'm intimidated no longer!  I've been playing around with creating a custom scripting language for some of the code generation we're doing, and this turned out to be a really easy way to parse/compile the scripts.  Coco/R is distributed under the GPL, and source is available.  There are versions for both C# and Java. 

I was really impressed at how easy it was.  Basically you write an EBNF definition of your files to be parsed, and then annotate them with native (C# or Java) code that does the compilation.  Here's an example from the sample that comes with the distribution...

/*------------------------------------------------------------------------*/
MulOp<out int op>
=                        (. op = -1; .)
  ( '*'                  (. op = times; .)
  | '/'                  (. op = slash; .)
  ).
/*------------------------------------------------------------------------*/
RelOp<out int op>
=                        (. op = -1; .)
  ( '='                  (. op = equ; .)
  | '<'                  (. op = lss; .)
  | '>'                  (. op = gtr; .)
  ).

The EBNF stuff is on the left, and the native code on the right.  Super easy, and the parsers work great.  Very fast.  They are also very easy to debug, as the generated code is very well laid out.  It corresponds to the EBNF constructions, so debugging the process is very easy.

If you ever find yourself needing to do some parsing, check it out.

Turns out that if you have multiple versions of the same assembly, say 1.0.0.1 and 1.0.0.2 in your probing path, only one of them will ever get loaded.  Here's the deal...

I've got an app in

c:\myapp

in it are myassembly.dll v1.0.0.1 and myapp.exe.

There's a subdirectory

c:\myapp\new

that contains myassembly.dll v1.0.0.2, plus a new assembly newassembly.dll, which is dependent on v1.0.0.2 of myassembly.dll

In myapp.exe.config, I've included the "new" subdirectory in the applications private path, meaning that it will look there for assemblies when doing assembly binding.

 <runtime>
  <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
   <probing privatePath="new;"/>
  </assemblyBinding>
 </runtime>

When the application loads newassembly.dll, I would have thought that it would correctly load the 1.0.0.2 version of myassembly.dll, and that the application would load the 1.0.0.1 version to which it was bound.  Alas, that turns out not to be the case.  Fusion comes back with

LOG: Post-policy reference: myassembly, Version=1.0.0.2, Culture=neutral, PublicKeyToken=xxxyyyzzz
LOG: Cache Lookup was unsuccessful.
LOG: Attempting download of new URL file:///C:/myapp/myassembly.DLL.
LOG: Assembly download was successful. Attempting setup of file: C:\myapp\myassembly.DLL
LOG: Entering run-from-source setup phase.
WRN: Comparing the assembly name resulted in the mismatch: Build Number
ERR: The assembly reference did not match the assembly definition found.
ERR: Failed to complete setup of assembly (hr = 0x80131040). Probing terminated.

We had assumed that fusion would skip the wrong version and keep probing for the right one.  It looks like it just finds the wrong one and bails.  Of course, if we put both versions in the GAC, it works just like we would expect, which makes sense, that being what the GAC is for and everything.

I may just have a new favorite XML editor.  I caught wind of Stylus Studio 6 [via Mike Gunderloy] so I downloaded a trial copy and checked it out.  Wow.  I'm pretty impressed.  It's the same price as XMLSpy Pro, but includes support for XPath (v1 and v2), XQuery, Web Services testing, and a pretty good schema-to-schema mapping tool that creates XSLT files.  Plus it has a schema editor which looks pretty good, lots of data conversion tools, support for custom extensions (if you have your own file types), etc.  Lots of good stuff here.

What is even cooler is that they have a "Home" version for non-commercial use that has almost all of the features of the pro version (unlike the pretty well crippled XMLSpy Home) for only $50.  I'll definitely turn my students on to this next week.  That's a lot of functionality for very little money.  The schema editor in the Home version isn't quite as cool, and there are a few other features it doesn't support, like web services testing, but it looks otherwise pretty highly functional. 

If you don't care about the WSDL editor, there might be a lot to recommend in the Pro version over XMLSpy Enterprise, at about 1/3 of the price.