Simplify generics on Mapper.Builder (#56747)

Mapper.Builder currently has some complex generics on it to allow fluent builder
construction. However, the second parameter, a return type from the build() method,
is unnecessary, as we can use covariant return types. This commit removes this second
generic parameter.

Author: romseygeek

modules/mapper-extras/src/main/java/org/elasticsearch/index/mapper/RankFeatureFieldMapper.java

@@ -57,7 +57,7 @@ public static class Defaults {
         }
     }
 
-    public static class Builder extends FieldMapper.Builder<Builder, RankFeatureFieldMapper> {
+    public static class Builder extends FieldMapper.Builder<Builder> {
 
         public Builder(String name) {
             super(name, Defaults.FIELD_TYPE, Defaults.FIELD_TYPE);
@@ -85,7 +85,7 @@ public RankFeatureFieldMapper build(BuilderContext context) {
 
     public static class TypeParser implements Mapper.TypeParser {
         @Override
-        public Mapper.Builder<?,?> parse(String name, Map<String, Object> node, ParserContext parserContext) throws MapperParsingException {
+        public Mapper.Builder<?> parse(String name, Map<String, Object> node, ParserContext parserContext) throws MapperParsingException {
             RankFeatureFieldMapper.Builder builder = new RankFeatureFieldMapper.Builder(name);
             for (Iterator<Map.Entry<String, Object>> iterator = node.entrySet().iterator(); iterator.hasNext();) {
                 Map.Entry<String, Object> entry = iterator.next();

modules/mapper-extras/src/main/java/org/elasticsearch/index/mapper/RankFeatureMetaFieldMapper.java

@@ -55,7 +55,7 @@ public static class Defaults {
         }
     }
 
-    public static class Builder extends MetadataFieldMapper.Builder<Builder, RankFeatureMetaFieldMapper> {
+    public static class Builder extends MetadataFieldMapper.Builder<Builder> {
 
         public Builder(MappedFieldType existing) {
             super(NAME, existing == null ? Defaults.FIELD_TYPE : existing, Defaults.FIELD_TYPE);
@@ -70,7 +70,7 @@ public RankFeatureMetaFieldMapper build(BuilderContext context) {
 
     public static class TypeParser implements MetadataFieldMapper.TypeParser {
         @Override
-        public MetadataFieldMapper.Builder<?,?> parse(String name,
+        public MetadataFieldMapper.Builder<?> parse(String name,
                 Map<String, Object> node, ParserContext parserContext) throws MapperParsingException {
             return new Builder(parserContext.mapperService().fieldType(NAME));
         }

modules/mapper-extras/src/main/java/org/elasticsearch/index/mapper/RankFeaturesFieldMapper.java

@@ -51,7 +51,7 @@ public static class Defaults {
         }
     }
 
-    public static class Builder extends FieldMapper.Builder<Builder, RankFeaturesFieldMapper> {
+    public static class Builder extends FieldMapper.Builder<Builder> {
 
         public Builder(String name) {
             super(name, Defaults.FIELD_TYPE, Defaults.FIELD_TYPE);
@@ -74,7 +74,7 @@ public RankFeaturesFieldMapper build(BuilderContext context) {
 
     public static class TypeParser implements Mapper.TypeParser {
         @Override
-        public Mapper.Builder<?,?> parse(String name, Map<String, Object> node, ParserContext parserContext) throws MapperParsingException {
+        public Mapper.Builder<?> parse(String name, Map<String, Object> node, ParserContext parserContext) throws MapperParsingException {
             RankFeaturesFieldMapper.Builder builder = new RankFeaturesFieldMapper.Builder(name);
             return builder;
         }

modules/mapper-extras/src/main/java/org/elasticsearch/index/mapper/ScaledFloatFieldMapper.java

@@ -82,7 +82,7 @@ public class ScaledFloatFieldMapper extends FieldMapper {
     // use the same default as numbers
     private static final Setting<Boolean> COERCE_SETTING = NumberFieldMapper.COERCE_SETTING;
 
-    public static class Builder extends FieldMapper.Builder<Builder, ScaledFloatFieldMapper> {
+    public static class Builder extends FieldMapper.Builder<Builder> {
 
         private boolean scalingFactorSet = false;
         private Boolean ignoreMalformed;
@@ -149,7 +149,7 @@ public ScaledFloatFieldMapper build(BuilderContext context) {
     public static class TypeParser implements Mapper.TypeParser {
 
         @Override
-        public Mapper.Builder<?,?> parse(String name, Map<String, Object> node,
+        public Mapper.Builder<?> parse(String name, Map<String, Object> node,
                                          ParserContext parserContext) throws MapperParsingException {
             Builder builder = new Builder(name);
             TypeParsers.parseField(builder, name, node, parserContext);

modules/mapper-extras/src/main/java/org/elasticsearch/index/mapper/SearchAsYouTypeFieldMapper.java

@@ -104,7 +104,7 @@ public static class Defaults {
     public static class TypeParser implements Mapper.TypeParser {
 
         @Override
-        public Mapper.Builder<?, ?> parse(String name,
+        public Mapper.Builder<?> parse(String name,
                                           Map<String, Object> node,
                                           ParserContext parserContext) throws MapperParsingException {
 
@@ -129,7 +129,7 @@ public static class TypeParser implements Mapper.TypeParser {
         }
     }
 
-    public static class Builder extends FieldMapper.Builder<Builder, SearchAsYouTypeFieldMapper> {
+    public static class Builder extends FieldMapper.Builder<Builder> {
         private int maxShingleSize = Defaults.MAX_SHINGLE_SIZE;
 
         public Builder(String name) {

modules/mapper-extras/src/main/java/org/elasticsearch/index/mapper/TokenCountFieldMapper.java

@@ -47,7 +47,7 @@ public static class Defaults {
         public static final boolean DEFAULT_POSITION_INCREMENTS = true;
     }
 
-    public static class Builder extends FieldMapper.Builder<Builder, TokenCountFieldMapper> {
+    public static class Builder extends FieldMapper.Builder<Builder> {
         private NamedAnalyzer analyzer;
         private boolean enablePositionIncrements = Defaults.DEFAULT_POSITION_INCREMENTS;
 
@@ -84,7 +84,7 @@ public TokenCountFieldMapper build(BuilderContext context) {
 
     public static class TypeParser implements Mapper.TypeParser {
         @Override
-        public Mapper.Builder<?,?> parse(String name, Map<String, Object> node, ParserContext parserContext) throws MapperParsingException {
+        public Mapper.Builder<?> parse(String name, Map<String, Object> node, ParserContext parserContext) throws MapperParsingException {
             TokenCountFieldMapper.Builder builder = new TokenCountFieldMapper.Builder(name);
             for (Iterator<Map.Entry<String, Object>> iterator = node.entrySet().iterator(); iterator.hasNext();) {
                 Map.Entry<String, Object> entry = iterator.next();

modules/parent-join/src/main/java/org/elasticsearch/join/mapper/MetaJoinFieldMapper.java

@@ -57,7 +57,7 @@ static class Defaults {
         }
     }
 
-    static class Builder extends FieldMapper.Builder<Builder, MetaJoinFieldMapper> {
+    static class Builder extends FieldMapper.Builder<Builder> {
         Builder() {
             super(NAME, Defaults.FIELD_TYPE, Defaults.FIELD_TYPE);
             builder = this;

modules/parent-join/src/main/java/org/elasticsearch/join/mapper/ParentIdFieldMapper.java

@@ -66,7 +66,7 @@ static class Defaults {
         }
     }
 
-    static class Builder extends FieldMapper.Builder<Builder, ParentIdFieldMapper> {
+    static class Builder extends FieldMapper.Builder<Builder> {
         private final String parent;
         private final Set<String> children;
 

modules/parent-join/src/main/java/org/elasticsearch/join/mapper/ParentJoinFieldMapper.java

@@ -121,7 +121,7 @@ private static void checkParentFields(String name, List<ParentIdFieldMapper> map
         }
     }
 
-    public static class Builder extends FieldMapper.Builder<Builder, ParentJoinFieldMapper> {
+    public static class Builder extends FieldMapper.Builder<Builder> {
         final List<ParentIdFieldMapper.Builder> parentIdFieldBuilders = new ArrayList<>();
         boolean eagerGlobalOrdinals = true;
 
@@ -168,7 +168,7 @@ public ParentJoinFieldMapper build(BuilderContext context) {
 
     public static class TypeParser implements Mapper.TypeParser {
         @Override
-        public Mapper.Builder<?,?> parse(String name, Map<String, Object> node, ParserContext parserContext) throws MapperParsingException {
+        public Mapper.Builder<?> parse(String name, Map<String, Object> node, ParserContext parserContext) throws MapperParsingException {
             final IndexSettings indexSettings = parserContext.mapperService().getIndexSettings();
             checkIndexCompatibility(indexSettings, name);
 

modules/percolator/src/main/java/org/elasticsearch/percolator/PercolatorFieldMapper.java

@@ -108,7 +108,7 @@ public class PercolatorFieldMapper extends FieldMapper {
     static final String RANGE_FIELD_NAME = "range_field";
     static final String MINIMUM_SHOULD_MATCH_FIELD_NAME = "minimum_should_match_field";
 
-    static class Builder extends FieldMapper.Builder<Builder, PercolatorFieldMapper> {
+    static class Builder extends FieldMapper.Builder<Builder> {
 
         private final Supplier<QueryShardContext> queryShardContext;