From 5d47ad4648d600eaf80a443bf011929f21825987 Mon Sep 17 00:00:00 2001
From: Simon Willnauer <simonw@apache.org>
Date: Sun, 28 Oct 2012 09:57:38 +0100
Subject: [PATCH] lucene 4: upgraded FuzzyQueryParser + Builder to use integer
 edit distance rather than floats (bw compatible)

---
 .../elasticsearch/index/query/FuzzyQueryBuilder.java  | 11 +++++++++++
 .../elasticsearch/index/query/FuzzyQueryParser.java   |  9 ++++++++-
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/src/main/java/org/elasticsearch/index/query/FuzzyQueryBuilder.java b/src/main/java/org/elasticsearch/index/query/FuzzyQueryBuilder.java
index 9a7c6e23139..f5360f30292 100644
--- a/src/main/java/org/elasticsearch/index/query/FuzzyQueryBuilder.java
+++ b/src/main/java/org/elasticsearch/index/query/FuzzyQueryBuilder.java
@@ -41,6 +41,9 @@ public class FuzzyQueryBuilder extends BaseQueryBuilder implements BoostableQuer
     private Integer prefixLength;
 
     private Integer maxExpansions;
+    
+    //LUCENE 4 UPGRADE  we need a testcase for this + documentation
+    private Boolean transpositions = true;
 
     /**
      * Constructs a new term query.
@@ -81,6 +84,11 @@ public class FuzzyQueryBuilder extends BaseQueryBuilder implements BoostableQuer
         this.maxExpansions = maxExpansions;
         return this;
     }
+    
+    public FuzzyQueryBuilder transpositions(boolean transpositions) {
+      this.transpositions = transpositions;
+      return this;
+    }
 
     @Override
     public void doXContent(XContentBuilder builder, Params params) throws IOException {
@@ -93,6 +101,9 @@ public class FuzzyQueryBuilder extends BaseQueryBuilder implements BoostableQuer
             if (boost != -1) {
                 builder.field("boost", boost);
             }
+            if (!transpositions) {
+                builder.field("transpositions", transpositions);
+            }
             if (minSimilarity != null) {
                 builder.field("min_similarity", minSimilarity);
             }
diff --git a/src/main/java/org/elasticsearch/index/query/FuzzyQueryParser.java b/src/main/java/org/elasticsearch/index/query/FuzzyQueryParser.java
index 56aa6dc4ea6..4da392305f0 100644
--- a/src/main/java/org/elasticsearch/index/query/FuzzyQueryParser.java
+++ b/src/main/java/org/elasticsearch/index/query/FuzzyQueryParser.java
@@ -60,9 +60,11 @@ public class FuzzyQueryParser implements QueryParser {
 
         String value = null;
         float boost = 1.0f;
+        //LUCENE 4 UPGRADE we should find a good default here I'd vote for 1.0 -> 1 edit
         String minSimilarity = "0.5";
         int prefixLength = FuzzyQuery.defaultPrefixLength;
         int maxExpansions = FuzzyQuery.defaultMaxExpansions;
+        boolean transpositions = true;
         MultiTermQuery.RewriteMethod rewriteMethod = null;
         token = parser.nextToken();
         if (token == XContentParser.Token.START_OBJECT) {
@@ -83,6 +85,8 @@ public class FuzzyQueryParser implements QueryParser {
                         prefixLength = parser.intValue();
                     } else if ("max_expansions".equals(currentFieldName) || "maxExpansions".equals(currentFieldName)) {
                         maxExpansions = parser.intValue();
+                    } else if ("transpositions".equals(currentFieldName)) {
+                      transpositions = parser.booleanValue();
                     } else if ("rewrite".equals(currentFieldName)) {
                         rewriteMethod = QueryParsers.parseRewriteMethod(parser.textOrNull(), null);
                     } else {
@@ -109,7 +113,10 @@ public class FuzzyQueryParser implements QueryParser {
             }
         }
         if (query == null) {
-            query = new FuzzyQuery(new Term(fieldName, value), Float.parseFloat(minSimilarity), prefixLength, maxExpansions);
+          //LUCENE 4 UPGRADE we need to document that this should now be an int rather than a float
+          int edits = FuzzyQuery.floatToEdits(Float.parseFloat(minSimilarity), 
+              value.codePointCount(0, value.length()));
+            query = new FuzzyQuery(new Term(fieldName, value), edits, prefixLength, maxExpansions, transpositions);
         }
         if (query instanceof MultiTermQuery) {
             QueryParsers.setRewriteMethod((MultiTermQuery) query, rewriteMethod);