as if's and switches, but it allows no loops. Filters are
interpreted. Filter using many features can be found in <file>filter/test.conf</file>.
-<p>You can find sources of filters language in <file>filter/</file>
-directory. <file>filter/config.Y</file> contains filter grammar, and basically translates source from
-user into tree of <cf>f_inst</cf> structures. These trees are later interpreted using code in
-<file>filter/filter.c</file>. Filters internally work with values/variables in <tt>struct
-f_val</tt>, which contains type of value and value.
-
<p>Filter basically gets the route, looks at its attributes and
modifies some of them if it wishes. At the end, it decides, whether to
pass change route through (using <cf/accept/), or whether to <cf/reject/ given route. It looks