</itemizedlist>

  <para>
   A more complete example, which is directly useful for most European
   languages, can be found in <filename>unaccent.rules</filename>, which is installed
   in <filename>$SHAREDIR/tsearch_data/</filename> when the <filename>unaccent</filename>
   module is installed.  This rules file translates characters with accents
   to the same characters without accents, and it also expands ligatures
   into the equivalent series of simple characters (for example, &AElig; to
   AE).
  </para>
 </sect2>

 <sect2 id="unaccent-usage">
  <title>Usage</title>

  <para>
   Installing the <literal>unaccent</literal> extension creates a text
   search template <literal>unaccent</literal> and a dictionary <literal>unaccent</literal>
   based on it.  The <literal>unaccent</literal> dictionary has the default
   parameter setting <literal>RULES='unaccent'</literal>, which makes it immediately
   usable with the standard <filename>unaccent.rules</filename> file.
   If you wish, you can alter the parameter, for example

<programlisting>
mydb=# ALTER TEXT SEARCH DICTIONARY unaccent (RULES='my_rules');
</programlisting>

   or create new dictionaries based on the template.
  </para>

  <para>
   To test the dictionary, you can try:
<programlisting>
mydb=# select ts_lexize('unaccent','H&ocirc;tel');
 ts_lexize
-----------
 {Hotel}
(1 row)
</programlisting>
  </para>

  <para>
   Here is an example showing how to insert the
   <filename>unaccent</filename> dictionary into a text search configuration:
<programlisting>
mydb=# CREATE TEXT SEARCH CONFIGURATION fr ( COPY = french );
mydb=# ALTER TEXT SEARCH CONFIGURATION fr
        ALTER MAPPING FOR hword, hword_part, word
        WITH unaccent, french_stem;
mydb=# select to_tsvector('fr','H&ocirc;tels de la Mer');
    to_tsvector
-------------------
 'hotel':1 'mer':4
(1 row)

mydb=# select to_tsvector('fr','H&ocirc;tel de la Mer') @@ to_tsquery('fr','Hotels');
 ?column?
----------
 t
(1 row)

mydb=# select ts_headline('fr','H&ocirc;tel de la Mer',to_tsquery('fr','Hotels'));
      ts_headline
------------------------
 &lt;b&gt;H&ocirc;tel&lt;/b&gt; de la Mer
(1 row)
</programlisting>
  </para>
 </sect2>

 <sect2 id="unaccent-functions">
 <title>Functions</title>

 <para>
  The <function>unaccent()</function> function removes accents (diacritic signs) from
  a given string.  Basically, it's a wrapper around
  <filename>unaccent</filename>-type dictionaries, but it can be used outside normal
  text search contexts.
 </para>

 <indexterm>
  <primary>unaccent</primary>
 </indexterm>

<synopsis>
unaccent(<optional><replaceable class="parameter">dictionary</replaceable> <type>regdictionary</type>, </optional> <replaceable class="parameter">string</replaceable> <type>text</type>) returns <type>text</type>
</synopsis>

 <para>
  If the <replaceable class="parameter">dictionary</replaceable> argument is
  omitted, the text search dictionary named <literal>unaccent</literal> and
  appearing in the same schema as the <function>unaccent()</function>
  function itself is used.
 </para>

 <para>
  For example:
<programlisting>
SELECT unaccent('unaccent', 'H&ocirc;tel');
SELECT unaccent('H&ocirc;tel');
</programlisting>
 </para>
 </sect2>

</sect1>