Variables

Variables hold literal portions of PerlPoint code. This is handy for text that appears quite often, like a link address:

    $cpan=http://search.cpan.org

Here we meet the typical paragraph approach again. Variables are declared and assigned in special paragraphs beginning with a dollar character and the variable name, followed by the assignment. Everything behind the equal sign is treated as the variables new value - old values will be overwritten.

    // a variable value with whitespaces
    $whiteVar=variable with whitespaces

To use a variable, we just insert it to the PerlPoint source:

    This paragraph makes use of a variable
    to point to $cpan.

It's also possible to use it in a tag or macro option:

    Search \L{url="$cpan"}<CPAN>.

Variables are very handy to maintain a literal information (like a link) at a central place. In this regard they are similar to macros but evaluated in a different way:

• Variables are resolved once and as literals. Nested variables will not be resolved, nor are any PerlPoint syntax elements that might be included.
• While it is an error to refer to an undefined macro, it is valid to use an undefined variable. Undefined variables are treated as literal text.
• Being pure text, variables can be refered in templates.

Similar to macros, a backslash before a variable guards it from being evaluated.

    This \$variable is treated as text.

As an example, I use variables to store document informations such as author name and mail address, document date and version. Making this a convention allows to easily import those informations into generated pages.

    // document data
    Jochen Stenzel=Jochen Stenzel
  
    perl@jochen-stenzel.de=perl@jochen-stenzel.de
  
    2006-08-06=2005-05-30
  
    0.07=0.02

To reset a variable, just assign nothing:

    $var=