5.1.1 Example document

Let us start in the traditional way, with a (sort of) `hello world' program:

<!DOCTYPE programcode PUBLIC "-//Starlink//DTD Fortran Source Code 0.7//EN">
<title>The `hello world' program
<codegroup>
<title>Group title
<description>First test program
<routine>
<codeopener>
      subroutine helloworld (language)
<routineprologue>
   <routinename id=hi1>
     helloworld
   <description>
     Greets the world with a sunny hello
   <argumentlist>
   <parameter given>
     <name>language
     <type>_integer</type>
     <description>Selects the language to use.
     0=english, 1=sanskrit.
   <authorlist>
   <author id=ng affiliation='Glasgow'>Norman Gray
<codebody>
      write (*,*) 'ack!'
      end

This is, obviously, not a compilable Fortran program, but it is a good example, firstly because it displays the structure (which will be a little obscured when we come to consider Fortran programs in Section 5.2.1), and secondly because it could plausibly be the output of some script which extracts documentation from compilable source code files.

As mentioned above, the programcode DTD allow you to make heavy use of SGML tag omission features. As well as the usual such features, the Fortran code DTD allows further abbreviation, and we shall see that the above program could be represented as:

<!DOCTYPE programcode PUBLIC "-//Starlink//DTD Fortran Source Code 0.7//EN">
<title>The `hello world' program
<codegroup>
<title>Group title
<description>First test program
<routine>
<codeopener>
      subroutine helloworld (language)
*+
*   <routinename id=hi1>
*     helloworld
*   <description>
*     Greets the world with a sunny hello
*   <argumentlist>
*   <parameter given>
*     language = _integer
*     Selects the language to use.
*     0=english, 1=sanskrit.
*   <authorlist>
*   <author id=ng affiliation='Glasgow'>Norman Gray
*-
      write (*,*) 'ack!'
      end