Extract JpqlQueryRenderer out of JpqlQueryTransformer.

Move all the "boilerplate" operations out of JpqlQueryTransformer and into JpqlQueryRenderer. This visitor simply re-renders the original query provided. JpqlQueryTransform now extends it and ONLY overrides the relevant methods needed to apply sorting, counting, and other things.

Author: gregturn

spring-data-jpa/src/main/antlr4/org/springframework/data/jpa/repository/query/Jpql.g4

@@ -54,7 +54,13 @@ delete_statement
     ;
 
 from_clause
-    : FROM identification_variable_declaration (',' (identification_variable_declaration | collection_member_declaration))*
+    : FROM identification_variable_declaration (',' identificationVariableDeclarationOrCollectionMemberDeclaration )*
+    ;
+
+// This parser rule is needed to iterate over these two types from #from_clause
+identificationVariableDeclarationOrCollectionMemberDeclaration
+    : identification_variable_declaration
+    | collection_member_declaration
     ;
 
 identification_variable_declaration

spring-data-jpa/src/main/java/org/springframework/data/jpa/repository/query/HqlQueryRenderer.java

@@ -1207,12 +1207,15 @@ public List<JpaQueryParsingToken> visitSimplePath(HqlParser.SimplePathContext ct
 		List<JpaQueryParsingToken> tokens = new ArrayList<>();
 
 		tokens.addAll(visit(ctx.identifier()));
+		NOSPACE(tokens);
 
 		ctx.simplePathElement().forEach(simplePathElementContext -> {
 			tokens.addAll(visit(simplePathElementContext));
+			NOSPACE(tokens);
 		});
+		SPACE(tokens);
 
-		return NOSPACE_ALL_BUT_LAST_ELEMENT(tokens, true);
+		return tokens;
 	}
 
 	@Override

spring-data-jpa/src/main/java/org/springframework/data/jpa/repository/query/HqlQueryTransformer.java

@@ -142,7 +142,7 @@ public List<JpaQueryParsingToken> visitOrderedQuery(HqlParser.OrderedQueryContex
 						NOSPACE(tokens);
 						tokens.add(TOKEN_CLOSE_PAREN);
 					}
-					tokens.add(new JpaQueryParsingToken(order.isDescending() ? "desc" : "asc", false));
+					tokens.add(order.isDescending() ? TOKEN_DESC : TOKEN_ASC);
 					tokens.add(TOKEN_COMMA);
 				});
 				CLIP(tokens);
@@ -258,14 +258,6 @@ public List<JpaQueryParsingToken> visitFromRoot(HqlParser.FromRootContext ctx) {
 		return tokens;
 	}
 
-	@Override
-	public List<JpaQueryParsingToken> visitInstantiation(HqlParser.InstantiationContext ctx) {
-
-		this.hasConstructorExpression = true;
-
-		return super.visitInstantiation(ctx);
-	}
-
 	@Override
 	public List<JpaQueryParsingToken> visitAlias(HqlParser.AliasContext ctx) {
 
@@ -335,4 +327,12 @@ public List<JpaQueryParsingToken> visitSelectClause(HqlParser.SelectClauseContex
 
 		return tokens;
 	}
+
+	@Override
+	public List<JpaQueryParsingToken> visitInstantiation(HqlParser.InstantiationContext ctx) {
+
+		this.hasConstructorExpression = true;
+
+		return super.visitInstantiation(ctx);
+	}
 }

spring-data-jpa/src/main/java/org/springframework/data/jpa/repository/query/JpaQueryParsingToken.java

@@ -144,34 +144,6 @@ static void NOSPACE(List<JpaQueryParsingToken> tokens) {
 		}
 	}
 
-	/**
-	 * Take a list of {@link JpaQueryParsingToken}s and convert them ALL to {@code space = false} (except possibly the
-	 * last one).
-	 * 
-	 * @param tokens
-	 * @param spacelastElement
-	 */
-	static List<JpaQueryParsingToken> NOSPACE_ALL_BUT_LAST_ELEMENT(List<JpaQueryParsingToken> tokens,
-			boolean spacelastElement) {
-
-		List<JpaQueryParsingToken> respacedTokens = tokens.stream() //
-				.map(queryParsingToken -> {
-
-					if (queryParsingToken.space == true) {
-						return new JpaQueryParsingToken(queryParsingToken.token, false);
-					} else {
-						return queryParsingToken;
-					}
-				}) //
-				.collect(Collectors.toList());
-
-		if (spacelastElement) {
-			SPACE(respacedTokens);
-		}
-
-		return respacedTokens;
-	}
-
 	/**
 	 * Drop the last entry from the list of {@link JpaQueryParsingToken}s.
 	 */