Traditionally programmers work with source code of a language directly within a text editor. In most language there are numerous automated tools to help with writing and viewing the source, but in the end the programmer still works directly on the source code.

An idea that I have heard more than once is that an IDE should only present a specific view of the source code, while the real source is hidden behind the scenes in a more general format, like XML. If a source file was really an XML file at its base, and rarely directly edited by a programmer, it could have many advantages.

One of many advantages is that history tracking could be embedded in the XML source, without being in the fact of programmers all the time. When I first look at source code, I like to see the history of revisions, who did what when or why. If this is embedded in the source code as comments, I often strip it so that the code is easier for me to work with, and I know I am not the only one. If the editor only presents me with a view of the source it could be a simple matter of checking a property option to turn history viewing on or off.

Given the following program:

program answer {
  _main() {
    // the question of life, the universe and everything
    x = 15 + 3 * 9;
    // the answer to life, the universe and everything
    write(x);
  }
}

<program name="answer">
  <function name="_main">
    <history>
      <modified>
        <author>Christoper Diggins</author>
        <date>10/21/2005</date>
        <license>BSD</license>
      </modified>
      <original>
        <author>unknown</author>
        <licence>Public Domain</licence>
        <url>http://www.somewhere.there</url>
      </original>
    </history>
    <statement>
      <raw>x = 15 + 3 * 9</raw>
      <ast>
        <push>x</push>
        <push>15</push>
        <push>3</push>
        <push>9</push>
        <call>_star</call>
        <call>_plus</call>
        <call>_eq</call>
      </ast>
      <comment>
        the question of life, the universe and everything
      </comment>
    </statement>
    <statement>
      <raw>write(x)</raw>
      <ast>
        <push>x</push>
        <call>write</call>
      </ast>
      <comment>
        the answer to life, the universe and everything
      </comment>
    </statement>
  </function>
</program>

<namespace name="heron">
  <namespace name="collections">
    <import>primitives</import>
    <history>
      <revision>
        <version>0.1</version>
        <author>Christopher Diggins</author>
        <date>10/21/2005</date>
        <archived>code:cdiggins.com/heron/collections/zips/hpc0-1.zip</archive d>
        <tests>code:cdiggins.com/heron/collections/tests/0-1/tests.xml</tests& gt;
      </revision>
      <revision>
        <version>0.0</version>
        <author>Christopher Diggins</author>
        <date>10/21/2005</date>
        <comments>This was the original version</comments>
        <license>Public Domain</license>
        <archived>www.nowhere.com</archived>
      </revision>
    </history>
    <license>Public Domain</license>
    <interface language="heron" name="Stack">
      <parameter>
        <metatype>type</metatype>
        <name>T</name>
        <concept>any</concept>
      </parameter>
      <function>
        <name>IsEmpty</name>
        <type>bool</type>
      </function>
      <function>
        <name>Push</name>
        <parameters>
          <parameter>
            <type>T^</type>
            <name>x</name>
          </parameter>
        </parameters>
        <exception>IsFull</exception>
      </function>
      <function>
        <name>Pop</name>
        <result>
          <type>T^</type>
        </result>
        <pre>
          <raw>!IsEmpty()</raw>
          <ast>
            <call>IsEmpty</call>
            <call>_bang</call>
            <call>_cast[bool]</call>
          </ast>
        </pre>
      </function>
    </interface>
  </namespace>
</namespace>