NAME

       Config::Grammar::Dynamic - A grammar-based, user-friendly config parser

DESCRIPTION

       Config::Grammar::Dynamic is like Config::Grammar but with some additional features useful
       for building configuration grammars that are dynamic, i.e.  where the syntax changes
       according to configuration entries in the same file.

       The following keys can be additionally specified in the grammar when using this module:

   Special Section Keys
       _dyn        A subroutine reference (function pointer) that will be called when a new
                   section of this syntax is encountered. The subroutine will get three
                   arguments: the syntax of the section name (string or regexp), the actual name
                   encountered (this will be the same as the first argument for non-regexp
                   sections) and a reference to the grammar tree of the section.  This subroutine
                   can then modify the grammar tree dynamically.

       _dyndoc     A hash reference that lists interesting names for the section that should be
                   documented. The keys of the hash are the names and the values in the hash are
                   strings that can contain an explanation for the name. The _dyn() subroutine is
                   then called for each of these names and the differences of the resulting
                   grammar and the original one are documented. This module can currently
                   document differences in the _vars list, listing new variables and removed
                   ones, and differences in the _sections list, listing the new and removed
                   sections.

       _recursive  Array containing the list of those sub-sections that are recursive, ie.  that
                   can contain a new sub-section with the same syntax as themselves.

                   The same effect can be accomplished with circular references in the grammar
                   tree or a suitable _dyn section subroutine (see below}, so this facility is
                   included just for convenience.

   Special Variable Keys
       _dyn        A subroutine reference (function pointer) that will be called when the
                   variable is assigned some value in the config file. The subroutine will get
                   three arguments: the name of the variable, the value assigned and a reference
                   to the grammar tree of this section.  This subroutine can then modify the
                   grammar tree dynamically.

                   Note that no _dyn() call is made for default and inherited values of the
                   variable.

       _dyndoc     A hash reference that lists interesting values for the variable that should be
                   documented. The keys of the hash are the values and the values in the hash are
                   strings that can contain an explanation for the value. The _dyn() subroutine
                   is then called for each of these values and the differences of the resulting
                   grammar and the original one are documented. This module can currently
                   document differences in the _vars list, listing new variables and removed
                   ones, and differences in the _sections list, listing the new and removed
                   sections.

COPYRIGHT

       Copyright (c) 2000-2005 by ETH Zurich. All rights reserved.  Copyright (c) 2007 by David
       Schweikert. All rights reserved.

LICENSE

       This program is free software; you can redistribute it and/or modify it under the same
       terms as Perl itself.

AUTHORS

       David Schweikert, Tobias Oetiker, Niko Tyni