docs/attachments/LUCENE-2880/LUCENE-2880.patch

Index: lucene/core/src/java/org/apache/lucene/search/spans/ContainSpans.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/search/spans/ContainSpans.java	(revision 1685832)
+++ lucene/core/src/java/org/apache/lucene/search/spans/ContainSpans.java	(working copy)
@@ -48,6 +48,11 @@
   }
 
   @Override
+  public int distance() {
+    return sourceSpans.distance();
+  }
+
+  @Override
   public void collect(SpanCollector collector) throws IOException {
     sourceSpans.collect(collector);
   }
Index: lucene/core/src/java/org/apache/lucene/search/spans/FilterSpans.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/search/spans/FilterSpans.java	(revision 1685832)
+++ lucene/core/src/java/org/apache/lucene/search/spans/FilterSpans.java	(working copy)
@@ -111,6 +111,11 @@
   }
 
   @Override
+  public int distance() {
+    return in.distance();
+  }
+
+  @Override
   public void collect(SpanCollector collector) throws IOException {
     in.collect(collector);
   }
Index: lucene/core/src/java/org/apache/lucene/search/spans/NearSpansOrdered.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/search/spans/NearSpansOrdered.java	(revision 1685832)
+++ lucene/core/src/java/org/apache/lucene/search/spans/NearSpansOrdered.java	(working copy)
@@ -129,6 +129,11 @@
   }
 
   @Override
+  public int distance() {
+    return matchWidth;
+  }
+
+  @Override
   public void collect(SpanCollector collector) throws IOException {
     for (Spans span : subSpans) {
       span.collect(collector);
Index: lucene/core/src/java/org/apache/lucene/search/spans/NearSpansUnordered.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/search/spans/NearSpansUnordered.java	(revision 1685832)
+++ lucene/core/src/java/org/apache/lucene/search/spans/NearSpansUnordered.java	(working copy)
@@ -115,6 +115,11 @@
     }
 
     @Override
+    public int distance() {
+      return in.distance();
+    }
+
+    @Override
     public void collect(SpanCollector collector) throws IOException {
       in.collect(collector);
     }
@@ -242,6 +247,11 @@
   }
 
   @Override
+  public int distance() {
+    return maxEndPositionCell.startPosition() - minPositionCell().startPosition();
+  }
+
+  @Override
   public void collect(SpanCollector collector) throws IOException {
     for (SpansCell cell : subSpanCells) {
       cell.collect(collector);
Index: lucene/core/src/java/org/apache/lucene/search/spans/SpanOrQuery.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/search/spans/SpanOrQuery.java	(revision 1685832)
+++ lucene/core/src/java/org/apache/lucene/search/spans/SpanOrQuery.java	(working copy)
@@ -329,6 +329,11 @@
         }
 
         @Override
+        public int distance() {
+          return topPositionSpans.distance();
+        }
+
+        @Override
         public void collect(SpanCollector collector) throws IOException {
           if (topPositionSpans != null)
             topPositionSpans.collect(collector);
Index: lucene/core/src/java/org/apache/lucene/search/spans/SpanScorer.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/search/spans/SpanScorer.java	(revision 1685832)
+++ lucene/core/src/java/org/apache/lucene/search/spans/SpanScorer.java	(working copy)
@@ -99,8 +99,7 @@
         freq = 1;
         return;
       }
-      int matchLength = endPos - startPos;
-      freq += docScorer.computeSlopFactor(matchLength);
+      freq += docScorer.computeSlopFactor(spans.distance());
       prevStartPos = startPos;
       prevEndPos = endPos;
       startPos = spans.nextStartPosition();
Index: lucene/core/src/java/org/apache/lucene/search/spans/Spans.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/search/spans/Spans.java	(revision 1685832)
+++ lucene/core/src/java/org/apache/lucene/search/spans/Spans.java	(working copy)
@@ -19,6 +19,7 @@
 
 import org.apache.lucene.search.DocIdSetIterator;
 import org.apache.lucene.search.TwoPhaseIterator;
+import org.apache.lucene.search.similarities.Similarity.SimScorer;
 
 import java.io.IOException;
 
@@ -50,6 +51,14 @@
   public abstract int endPosition();
 
   /**
+   * Return the distance to an ideal match, which is typically used to compute
+   * the {@link SimScorer#computeSlopFactor(int) slop factor}. It is only legal
+   * to call this method when the iterator is on a valid doc ID and positioned.
+   * The return value must be positive.
+   */
+  public abstract int distance();
+
+  /**
    * Collect postings data from the leaves of the current Spans.
    *
    * This method should only be called after {@link #nextStartPosition()}, and before
Index: lucene/core/src/java/org/apache/lucene/search/spans/TermSpans.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/search/spans/TermSpans.java	(revision 1685832)
+++ lucene/core/src/java/org/apache/lucene/search/spans/TermSpans.java	(working copy)
@@ -102,6 +102,11 @@
   }
 
   @Override
+  public int distance() {
+    return 0;
+  }
+
+  @Override
   public long cost() {
     return postings.cost();
   }
Index: lucene/core/src/test/org/apache/lucene/search/spans/JustCompileSearchSpans.java
===================================================================
--- lucene/core/src/test/org/apache/lucene/search/spans/JustCompileSearchSpans.java	(revision 1685832)
+++ lucene/core/src/test/org/apache/lucene/search/spans/JustCompileSearchSpans.java	(working copy)
@@ -61,6 +61,11 @@
     }
 
     @Override
+    public int distance() {
+      throw new UnsupportedOperationException(UNSUPPORTED_MSG);
+    }
+
+    @Override
     public void collect(SpanCollector collector) throws IOException {
 
     }
@@ -123,6 +128,11 @@
     }
 
     @Override
+    public int distance() {
+      throw new UnsupportedOperationException(UNSUPPORTED_MSG);
+    }
+
+    @Override
     public void collect(SpanCollector collector) throws IOException {
 
     }
Index: lucene/core/src/test/org/apache/lucene/search/spans/TestSpanSearchEquivalence.java
===================================================================
--- lucene/core/src/test/org/apache/lucene/search/spans/TestSpanSearchEquivalence.java	(revision 1685832)
+++ lucene/core/src/test/org/apache/lucene/search/spans/TestSpanSearchEquivalence.java	(working copy)
@@ -39,7 +39,7 @@
   /** SpanTermQuery(A) = TermQuery(A) */
   public void testSpanTermVersusTerm() throws Exception {
     Term t1 = randomTerm();
-    assertSameSet(new TermQuery(t1), spanQuery(new SpanTermQuery(t1)));
+    assertSameScores(new TermQuery(t1), spanQuery(new SpanTermQuery(t1)));
   }
   
   /** SpanOrQuery(A) = SpanTermQuery(A) */
@@ -154,7 +154,7 @@
                            };
     SpanQuery q1 = spanQuery(new SpanNearQuery(subquery, 0, true));
     PhraseQuery q2 = new PhraseQuery(t1.field(), t1.bytes(), t2.bytes());
-    assertSameSet(q1, q2);
+    assertSameScores(q1, q2);
   }
   
   /** SpanNearQuery([A, B], ∞, false) = +A +B */
Index: lucene/core/src/test/org/apache/lucene/search/spans/TestSpansAdvanced.java
===================================================================
--- lucene/core/src/test/org/apache/lucene/search/spans/TestSpansAdvanced.java	(revision 1685832)
+++ lucene/core/src/test/org/apache/lucene/search/spans/TestSpansAdvanced.java	(working copy)
@@ -100,7 +100,7 @@
    */
   public void testBooleanQueryWithSpanQueries() throws IOException {
     
-    doTestBooleanQueryWithSpanQueries(searcher, 0.3884282f);
+    doTestBooleanQueryWithSpanQueries(searcher, 0.54932045f);
   }
   
   /**
Index: lucene/core/src/test/org/apache/lucene/search/spans/TestSpansAdvanced2.java
===================================================================
--- lucene/core/src/test/org/apache/lucene/search/spans/TestSpansAdvanced2.java	(revision 1685832)
+++ lucene/core/src/test/org/apache/lucene/search/spans/TestSpansAdvanced2.java	(working copy)
@@ -86,8 +86,8 @@
     final Query spanQuery = new SpanTermQuery(new Term(FIELD_TEXT, "should"));
     final String[] expectedIds = new String[] {"B", "D", "1", "2", "3", "4",
         "A"};
-    final float[] expectedScores = new float[] {0.625f, 0.45927936f,
-        0.35355338f, 0.35355338f, 0.35355338f, 0.35355338f, 0.26516503f,};
+    final float[] expectedScores = new float[] {0.8838834f, 0.64951903f,
+        0.5f, 0.5f, 0.5f, 0.5f, 0.375f,};
     assertHits(searcher2, spanQuery, "single span query", expectedIds,
         expectedScores);
   }
@@ -104,8 +104,7 @@
     query.add(spanQuery2, BooleanClause.Occur.MUST);
     final String[] expectedIds = new String[] {"D", "A"};
     // these values were pre LUCENE-413
-    // final float[] expectedScores = new float[] { 0.93163157f, 0.20698164f };
-    final float[] expectedScores = new float[] {1.0191123f, 0.93163157f};
+    final float[] expectedScores = new float[] {1.44124233f, 1.31752586f};
     assertHits(searcher2, query, "multiple different span queries",
         expectedIds, expectedScores);
   }
@@ -116,6 +115,6 @@
   @Override
   public void testBooleanQueryWithSpanQueries() throws IOException {
     
-    doTestBooleanQueryWithSpanQueries(searcher2, 0.73500174f);
+    doTestBooleanQueryWithSpanQueries(searcher2, 1.0394494f);
   }
 }
Index: lucene/test-framework/src/java/org/apache/lucene/search/spans/AssertingSpans.java
===================================================================
--- lucene/test-framework/src/java/org/apache/lucene/search/spans/AssertingSpans.java	(revision 1685832)
+++ lucene/test-framework/src/java/org/apache/lucene/search/spans/AssertingSpans.java	(working copy)
@@ -125,6 +125,14 @@
   }
 
   @Override
+  public int distance() {
+    assert state == State.ITERATING;
+    final int distance = in.distance();
+    assert distance >= 0;
+    return distance;
+  }
+
+  @Override
   public void collect(SpanCollector collector) throws IOException {
     assert state == State.ITERATING : "collect() called in illegal state: " + state + ": " + in;
     in.collect(collector);