document Christoph's improvements to FuzzyQuery

git-svn-id: https://svn.apache.org/repos/asf/lucene/java/trunk@150508 13f79535-47bb-0310-9956-ffa450edef68

CHANGES.txt

@@ -11,7 +11,12 @@ $Id$
 
  2. FuzzyQuery now takes an additional parameter that specifies the
     minimum similarity that is required for a term to match the query.
-    Note that this isn't supported by QueryParser yet. (Daniel Naber)
+    The QueryParser syntax for this is term~x, where x is a floating 
+    point number between 0 and 1 (a bigger number means that a higher
+    similarity is required). Furthermore, a prefix can be specified
+    for FuzzyQuerys so that only those terms are considered similar that 
+    start with this prefix. This can speed up FuzzyQuery greatly.
+    (Daniel Naber, Christoph Goller)
   
  3. The Russian and the German analyzers have been moved to Sandbox.
     Also, the WordlistLoader class has been moved one level up in the

docs/queryparsersyntax.html

@@ -385,7 +385,28 @@ limitations under the License.
     </tr>
     </table>
     </div>
-                                                <p>This search will find terms like foam and roams</p>
+                                                <p>This search will find terms like foam and roams.</p>
+                                                <p>Starting with Lucene 1.9 an additional (optional) parameter can specify the required similarity. The value is between 0 and 1, with a value closer to 1 only terms with a higher similarity will be matched. For example:</p>
+                                                    <div align="left">
+    <table cellspacing="4" cellpadding="0" border="0">
+    <tr>
+      <td bgcolor="#023264" width="1" height="1"><img src="/images/void.gif" width="1" height="1" vspace="0" hspace="0" border="0"/></td>
+      <td bgcolor="#023264" height="1"><img src="/images/void.gif" width="1" height="1" vspace="0" hspace="0" border="0"/></td>
+      <td bgcolor="#023264" width="1" height="1"><img src="/images/void.gif" width="1" height="1" vspace="0" hspace="0" border="0"/></td>
+    </tr>
+    <tr>
+      <td bgcolor="#023264" width="1"><img src="/images/void.gif" width="1" height="1" vspace="0" hspace="0" border="0"/></td>
+      <td bgcolor="#ffffff"><pre>roam~0.8</pre></td>
+      <td bgcolor="#023264" width="1"><img src="/images/void.gif" width="1" height="1" vspace="0" hspace="0" border="0"/></td>
+    </tr>
+    <tr>
+      <td bgcolor="#023264" width="1" height="1"><img src="/images/void.gif" width="1" height="1" vspace="0" hspace="0" border="0"/></td>
+      <td bgcolor="#023264" height="1"><img src="/images/void.gif" width="1" height="1" vspace="0" hspace="0" border="0"/></td>
+      <td bgcolor="#023264" width="1" height="1"><img src="/images/void.gif" width="1" height="1" vspace="0" hspace="0" border="0"/></td>
+    </tr>
+    </table>
+    </div>
+                                                <p>The default that is used if the parameter is not given is 0.5.</p>
                             </blockquote>
       </td></tr>
       <tr><td><br/></td></tr>

xdocs/queryparsersyntax.xml

@@ -88,7 +88,11 @@
         <p>Lucene supports fuzzy searches based on the Levenshtein Distance, or Edit Distance algorithm. To do a fuzzy search use the tilde, "~", symbol at the end of a Single word Term. For example to search for a term similar in spelling to "roam" use the fuzzy search: </p>
 
         <source>roam~</source>
-        <p>This search will find terms like foam and roams</p>
+        <p>This search will find terms like foam and roams.</p>
+
+        <p>Starting with Lucene 1.9 an additional (optional) parameter can specify the required similarity. The value is between 0 and 1, with a value closer to 1 only terms with a higher similarity will be matched. For example:</p>
+        <source>roam~0.8</source>
+        <p>The default that is used if the parameter is not given is 0.5.</p>
         </subsection>