</para>
</sect2>
</sect1>
+ <sect1 id="zoom.facets"><title>Facets</title>
+ <para>
+ In case the target can and is requested to return facets, using a result set the ZOOM client
+ can request one or all facet fields. Using a facet field the client can request the term count and
+ then interate over the terms.
+ </para>
+ <synopsis>
+ ZOOM_facet_field *ZOOM_resultset_facets(ZOOM_resultset r);
+ const char ** ZOOM_resultset_facets_names(ZOOM_resultset r);
+ ZOOM_facet_field ZOOM_resultset_get_facet_field(ZOOM_resultset r, const char *facet_name);
+ ZOOM_facet_field ZOOM_resultset_get_facet_field_by_index(ZOOM_resultset r, int pos);
+ size_t ZOOM_resultset_facets_size(ZOOM_resultset r);
+
+ const char *ZOOM_facet_field_name(ZOOM_facet_field facet_field);
+ size_t ZOOM_facet_field_term_count(ZOOM_facet_field facet_field);
+ const char *ZOOM_facet_field_get_term(ZOOM_facet_field facet_field, size_t idx, int *freq);
+ </synopsis>
+ <para>
+ References to temporary structures are returned by all functions. They are only valid as long the Result set is valid.
+ <function>ZOOM_resultset_get_facet_field</function> or
+ <function>ZOOM_resultset_get_facet_field_by_index</function>.
+ <function>ZOOM_resultset_facets</function>.
+ <function>ZOOM_resultset_facets_names</function>.
+ <function>ZOOM_facet_field_name</function>.
+ <function>ZOOM_facet_field_get_term</function>.
+ </para>
+ <para id="zoom.resultset.get_facet_field">
+ A single Facet field is returned by function
+ <function>ZOOM_resultset_get_facet_field</function> or <function>ZOOM_resultset_get_facet_field_by_index</function> that takes a
+ result set and facet name or positive index respectively. First facet has position zero.
+ If no facet could be obtained (invalid name or index out of bounds) <literal>NULL</literal> is returned.
+ </para>
+ <para id="zoom.resultset.facets">
+ An array of facets field can be returned by <function>ZOOM_resultset_facets</function>. The length of the array is
+ given by <function>ZOOM_resultset_facets_size</function>. The array is zero-based and last entry will be at
+ <function>ZOOM_resultset_facets_size(result_set)</function>-1.
+ </para>
+ <para id="zoom.resultset.facets_names">
+ It is possible to interate over facets by name, by calling <function>ZOOM_resultset_facets_names</function>.
+ This will return an const array of char * where each string can be used as parameter for
+ <function>ZOOM_resultset_get_facet_field</function>.
+ </para>
+ </sect1>
<sect1 id="zoom.scan"><title>Scan</title>
<para>
This section describes an interface for Scan. Scan is not an