Xml Limitations

I just read a short article on ConciseXml. Some of the points made are very valid. 

·         Developers are incentivised to use short, abbreviated names because of the verbosity and bulk of Xml, sometimes reducing readability.

·         Attributes and elements have no clear standards for appropriate use, resulting in ambiguity in structure and content.

In the following example, Color is both an object with child objects and a simple field of an object.

<food>

       <item>

              <id>yx324</id>

              <food>chicken</color>

              <cost>10</cost>

       </item>

</food>

I don’t think this is necessarily a limitation of the Xml Standard!  This is a shortcoming on the part of the author.

If the same data were represented as:

<foods>

       <food id=”yx324” value=”chicken” cost=”10” />

</foods>

The data makes more sense to the reader and is less ambiguous.  This piece of data now stands on its own as something.  It’s apparent that foods is a collection of food items and each has an id value, a descriptive or title value and a cost.   

at this point, I suggest you move on...  the rest of this post is meandering observation but leads to this interesting concept

ConciseXml less verbose

Xml's purpose is to be self-describing. Some of the conventions described in the article violate that objective.

ConciseXML: <person "Mike" "Plusch"/>

in the above example, What is "Mike" and "Plusch" in the person node? Plusch could be a nickanme or a profession or an action.

XML 1.0: <person first="Mike" last="Plusch"/>

This syntax is obvious even out of context.

Xml as a programming language?

ConciseXml is a programming language.  Now it begins to become clear.  A new syntax to do the things we do everyday that merges data, presentation, logic…  Is this a good idea?  Do we really need another programming language?  What is the objective in making xml more than mark up?

I think it is both inappropriate and misleading to even call this Xml.  I don’t know yet whether it is an exciting technology or simply another new language that is designed to replace the syntax that people are used to.  I love curly braces.  I love parenthesis to separate and partition a multi-step equation.  I was ecstatic to leave VB behind and pick up c#.  Microsoft recognized that some of the common constructs for common programming concepts work really well.  They created C# and did a fabulous job making it make perfect sense.  Xml is the most intuitive way to represent data.  Sometimes it isn’t so efficient but there are a million ways to deal with performance. 

I don’t know Lisp but this looks a lot like Lisp to me.  I do like some of the concepts that I read about.  I like that a method is an object.  It would be nice to be able to pass a method in C#. 

Consider: 

Class:  “Animal”

Contains method: “Eat”

Which accepts parameters: “Animal” and “Digest” (Digest is an action)

In researching what C# can do, I found that a delegate can indeed be passed as a parameter!  Passing a method is dicey…  Leave the method where it is and pass the pointer.

// delegate declaration

delegate void MyDelegate(int i);

class Program

{

   public static void Main()

   {

      TakesADelegate(new MyDelegate(DelegateFunction));

   }

   public static void TakesADelegate(MyDelegate SomeFunction)

   {

      SomeFunction(21);

   }

   public static void DelegateFunction(int i)

   {

      System.Console.WriteLine("Called by delegate with number: {0}.", i);

   }

}

A delegate in C# allows you to pass methods of one class to objects of other classes that can call those methods.

See more on that here 

In my brief introduction to ConciseXml, I learned of a few grievances developers have with modern languages and standards and was able to learn about an available mechanism in C# (passing a delegate to a method of a class as a parameter) and some basic good practices with Xml – choice of attribute or element usage.

This makes me want to indeed write a program in Lisp.  I have repeatedly heard it improves a person’s overall perspective on programming. 

If I have some time, I may well do that.