factor out check if a token fits current search

Saves allocating an empty array.

lib-php/TokenWord.php

@@ -26,6 +26,22 @@ class Word
         return $this->iId;
     }
 
+    /**
+     * Check if the token can be added to the given search.
+     * Derive new searches by adding this token to an existing search.
+     *
+     * @param object  $oSearch      Partial search description derived so far.
+     * @param object  $oPosition    Description of the token position within
+                                    the query.
+     *
+     * @return True if the token is compatible with the search configuration
+     *         given the position.
+     */
+    public function isExtendable($oSearch, $oPosition)
+    {
+        return !$oPosition->isPhrase('country');
+    }
+
     /**
      * Derive new searches by adding this token to an existing search.
      *
@@ -37,10 +53,6 @@ class Word
      */
     public function extendSearch($oSearch, $oPosition)
     {
-        if ($oPosition->isPhrase('country')) {
-            return array();
-        }
-
         // Full words can only be a name if they appear at the beginning
         // of the phrase. In structured search the name must forcably in
         // the first phrase. In unstructured search it may be in a later