HSEARCH-4577 Do not use extra lambdas

Author: marko-bekhta

backend/elasticsearch/src/main/java/org/hibernate/search/backend/elasticsearch/search/projection/impl/ElasticsearchFieldProjection.java

@@ -121,7 +121,7 @@ protected boolean canDecodeArrays() {
 		public P transform(LoadingResult<?> loadingResult, A extractedData,
 				ProjectionTransformContext context) {
 			FromDocumentValueConvertContext convertContext = context.fromDocumentValueConvertContext();
-			A transformedData = accumulator.transformAll( extractedData, converter::fromDocumentValue, convertContext );
+			A transformedData = accumulator.transformAll( extractedData, converter.delegate(), convertContext );
 			return accumulator.finish( transformedData );
 		}
 	}

backend/lucene/src/main/java/org/hibernate/search/backend/lucene/search/projection/impl/LuceneFieldProjection.java

@@ -143,7 +143,7 @@ protected A accumulate(A accumulated, int docId) {
 		@Override
 		public P transform(LoadingResult<?> loadingResult, A extractedData, ProjectionTransformContext context) {
 			FromDocumentValueConvertContext convertContext = context.fromDocumentValueConvertContext();
-			A transformedData = accumulator.transformAll( extractedData, converter::fromDocumentValue, convertContext );
+			A transformedData = accumulator.transformAll( extractedData, converter.delegate(), convertContext );
 			return accumulator.finish( transformedData );
 		}
 	}

engine/src/main/java/org/hibernate/search/engine/backend/types/converter/spi/ProjectionConverter.java

@@ -88,4 +88,11 @@ public boolean isCompatibleWith(ProjectionConverter<?, ?> other) {
 		return delegate.isCompatibleWith( other.delegate );
 	}
 
+
+	/**
+	 * @return The document value converter that is backing up this converter.
+	 */
+	public FromDocumentValueConverter<? super F, V> delegate() {
+		return delegate;
+	}
 }

engine/src/main/java/org/hibernate/search/engine/search/projection/spi/ProjectionAccumulator.java

@@ -134,7 +134,7 @@ default A accumulateAll(A accumulated, Collection<E> values) {
 	 */
 	default A transformAll(A accumulated, ProjectionConverter<? super E, ? extends V> converter,
 			FromDocumentValueConvertContext context) {
-		return transformAll( accumulated, converter::fromDocumentValue, context );
+		return transformAll( accumulated, converter.delegate(), context );
 	}
 
 	/**

util/internal/integrationtest/common/src/main/java/org/hibernate/search/util/impl/integrationtest/common/stub/backend/search/projection/impl/StubFieldProjection.java

@@ -62,7 +62,7 @@ public A extract(ProjectionHitMapper<?> projectionHitMapper, Iterator<?> project
 	public P transform(LoadingResult<?> loadingResult, Object extractedData,
 			StubSearchProjectionContext context) {
 		A accumulated = (A) extractedData;
-		A transformedData = accumulator.transformAll( accumulated, converter::fromDocumentValue,
+		A transformedData = accumulator.transformAll( accumulated, converter.delegate(),
 				context.fromDocumentValueConvertContext() );
 		return accumulator.finish( transformedData );
 	}