Added rewrite methods to all SpanQuery subclasses that nest SpanQuerys

git-svn-id: https://svn.apache.org/repos/asf/lucene/java/trunk@289556 13f79535-47bb-0310-9956-ffa450edef68

CHANGES.txt

@@ -145,6 +145,7 @@ New features
 20. Added a new class MatchAllDocsQuery that matches all documents.
     (John Wang via Daniel Naber, bug #34946)
 
+
 API Changes
 
  1. Several methods and fields have been deprecated. The API documentation 
@@ -165,6 +166,10 @@ API Changes
  4. Add a serializable Parameter Class to standardize parameter enum
     classes in BooleanClause and Field. (Christoph)
 
+ 5. Added rewrite methods to all SpanQuery subclasses that nest other SpanQuerys.
+    This allows custom SpanQuery subclasses that rewrite (for term expansion, for
+    example) to nest within the built-in SpanQuery classes successfully.
+
 Bug fixes
 
  1. The JSP demo page (src/jsp/results.jsp) now properly closes the 

src/java/org/apache/lucene/search/spans/SpanFirstQuery.java

@@ -21,6 +21,7 @@ import java.io.IOException;
 import java.util.Collection;
 
 import org.apache.lucene.index.IndexReader;
+import org.apache.lucene.search.Query;
 
 /** Matches spans near the beginning of a field. */
 public class SpanFirstQuery extends SpanQuery {
@@ -87,4 +88,19 @@ public class SpanFirstQuery extends SpanQuery {
       };
   }
 
+  public Query rewrite(IndexReader reader) throws IOException {
+    SpanFirstQuery clone = null;
+
+    SpanQuery rewritten = (SpanQuery) match.rewrite(reader);
+    if (rewritten != match) {
+      clone = (SpanFirstQuery) this.clone();
+      clone.match = rewritten;
+    }
+
+    if (clone != null) {
+      return clone;                        // some clauses rewrote
+    } else {
+      return this;                         // no clauses rewrote
+    }
+  }
 }

src/java/org/apache/lucene/search/spans/SpanNearQuery.java

@@ -25,6 +25,7 @@ import java.util.Iterator;
 
 
 import org.apache.lucene.index.IndexReader;
+import org.apache.lucene.search.Query;
 
 /** Matches spans which are near one another.  One can specify <i>slop</i>, the
  * maximum number of intervening unmatched positions, as well as whether
@@ -110,6 +111,24 @@ public class SpanNearQuery extends SpanQuery {
     return new NearSpans(this, reader);
   }
 
+  public Query rewrite(IndexReader reader) throws IOException {
+    SpanNearQuery clone = null;
+    for (int i = 0 ; i < clauses.size(); i++) {
+      SpanQuery c = (SpanQuery)clauses.get(i);
+      SpanQuery query = (SpanQuery) c.rewrite(reader);
+      if (query != c) {                     // clause rewrote: must clone
+        if (clone == null)
+          clone = (SpanNearQuery) this.clone();
+        clone.clauses.set(i,query);
+      }
+    }
+    if (clone != null) {
+      return clone;                        // some clauses rewrote
+    } else {
+      return this;                         // no clauses rewrote
+    }
+  }
+
   /** Returns true iff <code>o</code> is equal to this. */
   public boolean equals(Object o) {
     if (this == o) return true;

src/java/org/apache/lucene/search/spans/SpanNotQuery.java

@@ -21,6 +21,7 @@ import java.io.IOException;
 import java.util.Collection;
 
 import org.apache.lucene.index.IndexReader;
+import org.apache.lucene.search.Query;
 
 /** Removes matches which overlap with another SpanQuery. */
 public class SpanNotQuery extends SpanQuery {
@@ -127,4 +128,25 @@ public class SpanNotQuery extends SpanQuery {
       };
   }
 
+  public Query rewrite(IndexReader reader) throws IOException {
+    SpanNotQuery clone = null;
+
+    SpanQuery rewrittenInclude = (SpanQuery) include.rewrite(reader);
+    if (rewrittenInclude != include) {
+      clone = (SpanNotQuery) this.clone();
+      clone.include = rewrittenInclude;
+    }
+    SpanQuery rewrittenExclude = (SpanQuery) exclude.rewrite(reader);
+    if (rewrittenExclude != include) {
+      if (clone == null) clone = (SpanNotQuery) this.clone();
+      clone.exclude = rewrittenExclude;
+    }
+
+    if (clone != null) {
+      return clone;                        // some clauses rewrote
+    } else {
+      return this;                         // no clauses rewrote
+    }
+  }
+
 }

src/java/org/apache/lucene/search/spans/SpanOrQuery.java

@@ -25,6 +25,7 @@ import java.util.Iterator;
 
 import org.apache.lucene.index.IndexReader;
 import org.apache.lucene.util.PriorityQueue;
+import org.apache.lucene.search.Query;
 
 /** Matches the union of its clauses.*/
 public class SpanOrQuery extends SpanQuery {
@@ -64,6 +65,24 @@ public class SpanOrQuery extends SpanQuery {
     return terms;
   }
 
+  public Query rewrite(IndexReader reader) throws IOException {
+    SpanOrQuery clone = null;
+    for (int i = 0 ; i < clauses.size(); i++) {
+      SpanQuery c = (SpanQuery)clauses.get(i);
+      SpanQuery query = (SpanQuery) c.rewrite(reader);
+      if (query != c) {                     // clause rewrote: must clone
+        if (clone == null)
+          clone = (SpanOrQuery) this.clone();
+        clone.clauses.set(i,query);
+      }
+    }
+    if (clone != null) {
+      return clone;                        // some clauses rewrote
+    } else {
+      return this;                         // no clauses rewrote
+    }
+  }
+
   public String toString(String field) {
     StringBuffer buffer = new StringBuffer();
     buffer.append("spanOr([");