[Zodb-checkins] CVS: Packages/ZConfig/doc - zconfig.tex:1.24

Fred L. Drake, Jr. fred@zope.com
Wed, 4 Dec 2002 17:01:07 -0500

Update of /cvs-repository/Packages/ZConfig/doc
In directory cvs.zope.org:/tmp/cvs-serv20174

Modified Files:
Log Message:
Better explanation of %define.

=== Packages/ZConfig/doc/zconfig.tex 1.23 => 1.24 ===
--- Packages/ZConfig/doc/zconfig.tex:1.23	Wed Dec  4 16:20:43 2002
+++ Packages/ZConfig/doc/zconfig.tex	Wed Dec  4 17:01:07 2002
@@ -180,16 +180,46 @@
 \subsection{Textual Substitution in Values}
-XXX Explain \keyword{\%define} and \$-substitution here.
+\module{ZConfig} provides a limited way to re-use portions of a value
+using simple string substitution.  To use this facility, define named
+bits of replacement text using the \keyword{\%define} directive, and
+reference these texts from values.
-In this example, the value for the \code{key} will evaluate to
+The syntax for \keyword{\%define} is:
+%define \var{name} \optional{\var{value}}
+The value of \var{name} must be a sequence of letters, digits, and
+underscores, and may not start with a digit.  If \var{value} is
+omitted, it will be the empty string.  If given, there must be
+whitespace between \var{name} and \var{value}; \var{value} will not
+include any whitespace on either side, just like values from key-value
+Names must be defined before they are used, and may not be
+re-defined.  All names are associated with the source text in which
+they are defined, so distinct sources which are referenced using
+\keyword{\%import} or \keyword{\%include} are not affected by
+definitions created by the resource being parsed.
+References to defined names from configuration values use the syntax
+described for the \refmodule{ZConfig.Substitution} module.
+Configuration values which include a \character{\$} as part of the
+actual value will need to use \code{\$\$} to get a single
+\character{\$} in the result.
+The values of defined names are not processed in any way, and may not
+contain references to named definitions.
+For example, the value for the \code{key} will evaluate to
 %define name value
 key $name
-\end{verbatim} %$
+\end{verbatim} %$ <-- bow to font-lock
 \section{\module{ZConfig} --- Basic configuration support}