Complex variable names

Normally, variable names are simple strings such as {ChapNum}. However if we have another variable {Num} with value 6 the <set/> command allows us to assign to constructed variable names as follows:

<set var="List_{Num}" string="6th value"/>

To retrieve the value of a variable with a constructed name, you can use the copy option. For example:

<set var="Temp" copy="List_{Num}" />

If you require complex variable handling, you can set up custom markers to call the required Perl functions. As a full fledged programming language, Perl offers comprehensive string, list and hash functionality sufficient for the most demanding requirements.

[Warning] Warning

It is a fatal error if a copy attribute does not evaluate to a valid variable name. It is a runtime error if the named variable does not exist.