Code style: lint

The next commit adds various lint rules. This commit fixes
the errors detected by those rules in existing code.

babel/src/test/resources/sql/big-query.iq

@@ -686,8 +686,8 @@ SELECT SAFE_ADD(CAST('NaN' AS DOUBLE), CAST(3 as BIGINT)) as NaN_result;
 #
 # SAFE_DIVIDE(value1, value2)
 #
-# Equivalent to the divide operator (/), but returns NULL if overflow/underflow occurs 
-# or if value2 is zero.
+# Equivalent to the divide operator (/), but returns NULL if
+# overflow/underflow occurs or if value2 is zero.
 SELECT SAFE_DIVIDE(20, 4) as result;
 +--------+
 | result |
@@ -709,7 +709,8 @@ SELECT SAFE_DIVIDE(-9223372036854775806, 0) as zero_result;
 
 !ok
 
-SELECT SAFE_DIVIDE(CAST(1.7e308 as DOUBLE), CAST(1.7e-308 as DOUBLE)) as double_overflow;
+SELECT SAFE_DIVIDE(CAST(1.7e308 as DOUBLE),
+        CAST(1.7e-308 as DOUBLE)) as double_overflow;
 +-----------------+
 | double_overflow |
 +-----------------+
@@ -719,8 +720,8 @@ SELECT SAFE_DIVIDE(CAST(1.7e308 as DOUBLE), CAST(1.7e-308 as DOUBLE)) as double_
 
 !ok
 
-SELECT SAFE_DIVIDE(CAST(-3.5e75 AS DECIMAL(76, 0)), CAST(3.5e-75 AS DECIMAL(76, 0))) 
-    as decimal_overflow;
+SELECT SAFE_DIVIDE(CAST(-3.5e75 AS DECIMAL(76, 0)),
+        CAST(3.5e-75 AS DECIMAL(76, 0))) as decimal_overflow;
 +------------------+
 | decimal_overflow |
 +------------------+
@@ -751,6 +752,7 @@ SELECT SAFE_DIVIDE(1, CAST(1 AS DOUBLE) / CAST(9223372036854775807 AS DOUBLE)) a
 (1 row)
 
 !ok
+
 #####################################################################
 # SAFE_MULTIPLY
 #

core/src/main/java/org/apache/calcite/adapter/enumerable/EnumUtils.java

@@ -614,7 +614,7 @@ static List<Expression> convertAssignableTypes(Class<?>[] targetTypes,
       }
     } else {
       int j = 0;
-      for (Expression argument: arguments) {
+      for (Expression argument : arguments) {
         Class<?> type;
         if (!targetTypes[j].isArray()) {
           type = targetTypes[j];

core/src/main/java/org/apache/calcite/adapter/enumerable/EnumerableLimitSort.java

@@ -98,21 +98,25 @@ public static EnumerableLimitSort create(
 
     final Expression fetchVal;
     if (this.fetch == null) {
-      fetchVal = Expressions.constant(Integer.valueOf(Integer.MAX_VALUE));
+      fetchVal = Expressions.constant(Integer.MAX_VALUE);
     } else {
       fetchVal = getExpression(this.fetch);
     }
 
-    final Expression offsetVal = this.offset == null ? Expressions.constant(Integer.valueOf(0))
-        : getExpression(this.offset);
+    final Expression offsetVal;
+    if (this.offset == null) {
+      offsetVal = Expressions.constant(0);
+    } else {
+      offsetVal = getExpression(this.offset);
+    }
 
     builder.add(
-        Expressions.return_(
-            null, Expressions.call(
-                BuiltInMethod.ORDER_BY_WITH_FETCH_AND_OFFSET.method, Expressions.list(
-                    childExp,
-                    builder.append("keySelector", pair.left))
-                    .appendIfNotNull(builder.appendIfNotNull("comparator", pair.right))
+        Expressions.return_(null,
+            Expressions.call(BuiltInMethod.ORDER_BY_WITH_FETCH_AND_OFFSET.method,
+                Expressions.list(childExp,
+                        builder.append("keySelector", pair.left))
+                    .appendIfNotNull(
+                        builder.appendIfNotNull("comparator", pair.right))
                     .appendIfNotNull(
                         builder.appendIfNotNull("offset",
                             Expressions.constant(offsetVal)))

core/src/main/java/org/apache/calcite/adapter/enumerable/RexImpTable.java

@@ -3762,7 +3762,7 @@ private abstract static class AbstractRexCallImplementor
         final List<RexToLixTranslator.Result> arguments) {
       final List<Expression> argIsNullList = new ArrayList<>();
       final List<Expression> argValueList = new ArrayList<>();
-      for (RexToLixTranslator.Result result: arguments) {
+      for (RexToLixTranslator.Result result : arguments) {
         argIsNullList.add(result.isNullVariable);
         argValueList.add(result.valueVariable);
       }
@@ -3950,7 +3950,7 @@ private static class LogicalAndImplementor extends AbstractRexCallImplementor {
     @Override public RexToLixTranslator.Result implement(final RexToLixTranslator translator,
         final RexCall call, final List<RexToLixTranslator.Result> arguments) {
       final List<Expression> argIsNullList = new ArrayList<>();
-      for (RexToLixTranslator.Result result: arguments) {
+      for (RexToLixTranslator.Result result : arguments) {
         argIsNullList.add(result.isNullVariable);
       }
       final List<Expression> nullAsTrue =
@@ -4004,7 +4004,7 @@ private static class LogicalOrImplementor extends AbstractRexCallImplementor {
     @Override public RexToLixTranslator.Result implement(final RexToLixTranslator translator,
         final RexCall call, final List<RexToLixTranslator.Result> arguments) {
       final List<Expression> argIsNullList = new ArrayList<>();
-      for (RexToLixTranslator.Result result: arguments) {
+      for (RexToLixTranslator.Result result : arguments) {
         argIsNullList.add(result.isNullVariable);
       }
       final List<Expression> nullAsFalse =

core/src/main/java/org/apache/calcite/interpreter/JoinNode.java

@@ -92,7 +92,7 @@ public JoinNode(Compiler compiler, Join rel) {
       // send un-match rows for full join on right source
       List<Row> empty = new ArrayList<>();
       // TODO: CALCITE-4308, JointNode in Interpreter might fail with NPE for FULL join
-      for (Row row: requireNonNull(innerRows, "innerRows")) {
+      for (Row row : requireNonNull(innerRows, "innerRows")) {
         if (matchRowSet.contains(row)) {
           continue;
         }
@@ -109,7 +109,7 @@ private List<Row> doJoin(Row outerRow, List<Row> innerRows,
     boolean outerRowOnLeft = joinRelType != JoinRelType.RIGHT;
     copyToContext(outerRow, outerRowOnLeft);
     List<Row> matchInnerRows = new ArrayList<>();
-    for (Row innerRow: innerRows) {
+    for (Row innerRow : innerRows) {
       copyToContext(innerRow, !outerRowOnLeft);
       final Boolean execute = (Boolean) condition.execute(context);
       if (execute != null && execute) {
@@ -135,7 +135,7 @@ private void doSend(Row outerRow, List<Row> matchInnerRows,
         boolean outerRowOnLeft = joinRelType != JoinRelType.RIGHT;
         copyToContext(outerRow, outerRowOnLeft);
         requireNonNull(context.values, "context.values");
-        for (Row row: matchInnerRows) {
+        for (Row row : matchInnerRows) {
           copyToContext(row, !outerRowOnLeft);
           sink.send(Row.asCopy(context.values));
         }

core/src/main/java/org/apache/calcite/interpreter/UncollectNode.java

@@ -35,7 +35,7 @@ public UncollectNode(Compiler compiler, Uncollect uncollect) {
   @Override public void run() throws InterruptedException {
     Row row = null;
     while ((row = source.receive()) != null) {
-      for (Object value: row.getValues()) {
+      for (Object value : row.getValues()) {
         if (value == null) {
           throw new NullPointerException("NULL value for unnest.");
         }

core/src/main/java/org/apache/calcite/jdbc/SimpleCalciteSchema.java

@@ -92,7 +92,7 @@ private SimpleCalciteSchema(@Nullable CalciteSchema parent,
       return lowerCaseName;
     }
     // Fall through: Set iteration
-    for (String candidate: candidates) {
+    for (String candidate : candidates) {
       if (candidate.equalsIgnoreCase(name)) {
         return candidate;
       }

core/src/main/java/org/apache/calcite/plan/SubstitutionVisitor.java

@@ -1746,7 +1746,7 @@ private static boolean sameRelCollectionNoOrderConsidered(
     if (list0.size() != list1.size()) {
       return false;
     }
-    for (MutableRel rel: list0) {
+    for (MutableRel rel : list0) {
       int index = list1.indexOf(rel);
       if (index == -1) {
         return false;
@@ -1766,7 +1766,7 @@ public static Pair<RexNode, List<RexNode>> explainCalc(MutableCalc calc) {
     final RexShuttle shuttle = getExpandShuttle(calc.program);
     final RexNode condition = shuttle.apply(calc.program.getCondition());
     final List<RexNode> projects = new ArrayList<>();
-    for (RexNode rex: shuttle.apply(calc.program.getProjectList())) {
+    for (RexNode rex : shuttle.apply(calc.program.getProjectList())) {
       projects.add(rex);
     }
     if (condition == null) {
@@ -1836,7 +1836,7 @@ private static boolean implies(
   private static boolean referenceByMapping(
       RexNode joinCondition, List<RexNode>... projectsOfInputs) {
     List<RexNode> projects = new ArrayList<>();
-    for (List<RexNode> projectsOfInput: projectsOfInputs) {
+    for (List<RexNode> projectsOfInput : projectsOfInputs) {
       projects.addAll(projectsOfInput);
     }
 

core/src/main/java/org/apache/calcite/plan/volcano/VolcanoPlanner.java

@@ -234,8 +234,9 @@ public VolcanoPlanner(@Nullable RelOptCostFactory costFactory,
     this.zeroCost = this.costFactory.makeZeroCost();
     this.infCost = this.costFactory.makeInfiniteCost();
     // If LOGGER is debug enabled, enable provenance information to be captured
-    this.provenanceMap = LOGGER.isDebugEnabled() ? new HashMap<>()
-        : Util.blackholeMap();
+    this.provenanceMap =
+        LOGGER.isDebugEnabled() ? new HashMap<>()
+            : Util.blackholeMap();
     initRuleQueue();
   }
 

core/src/main/java/org/apache/calcite/rel/convert/ConverterRule.java

@@ -61,8 +61,9 @@ protected ConverterRule(Config config) {
 
     // Most sub-classes are concerned with converting one convention to
     // another, and for them, the "out" field is a convenient short-cut.
-    this.out = outTrait instanceof Convention ? (Convention) outTrait
-        : castNonNull(null);
+    this.out =
+        outTrait instanceof Convention ? (Convention) outTrait
+            : castNonNull(null);
   }
 
   /**

core/src/main/java/org/apache/calcite/rel/externalize/RelDotWriter.java

@@ -236,10 +236,9 @@ private String formatNodeLabel(String label, int limit) {
     }
 
     List<String> descParts = new ArrayList<>();
-    for (int idx = 0; idx < label.length(); idx += option.maxNodeLabelPerLine()) {
-      int endIdx = idx + option.maxNodeLabelPerLine() > label.length() ? label.length()
-          : idx + option.maxNodeLabelPerLine();
-      descParts.add(label.substring(idx, endIdx));
+    for (int i = 0; i < label.length(); i += option.maxNodeLabelPerLine()) {
+      int endIdx = Math.min(i + option.maxNodeLabelPerLine(), label.length());
+      descParts.add(label.substring(i, endIdx));
     }
 
     return String.join("\\n", descParts) + (trimmed ? "..." : "");

core/src/main/java/org/apache/calcite/rel/hint/CompositeHintPredicate.java

@@ -65,15 +65,15 @@ public enum Composition {
   private boolean apply(Composition composition, RelHint hint, RelNode rel) {
     switch (composition) {
     case AND:
-      for (HintPredicate predicate: predicates) {
+      for (HintPredicate predicate : predicates) {
         if (!predicate.apply(hint, rel)) {
           return false;
         }
       }
       return true;
     case OR:
     default:
-      for (HintPredicate predicate: predicates) {
+      for (HintPredicate predicate : predicates) {
         if (predicate.apply(hint, rel)) {
           return true;
         }

core/src/main/java/org/apache/calcite/rel/metadata/RelMdColumnOrigins.java

@@ -152,7 +152,7 @@ private RelMdColumnOrigins() {}
       }
     };
     final List<RexNode> projects = new ArrayList<>();
-    for (RexNode rex: rexShuttle.apply(rel.getProgram().getProjectList())) {
+    for (RexNode rex : rexShuttle.apply(rel.getProgram().getProjectList())) {
       projects.add(rex);
     }
     final RexNode rexNode = projects.get(iOutputColumn);

core/src/main/java/org/apache/calcite/rel/metadata/RelMdColumnUniqueness.java

@@ -369,7 +369,7 @@ public Boolean areColumnsUnique(Intersect rel, RelMetadataQuery mq,
         return false;
       }
       final ImmutableBitSet.Builder targetColumns = ImmutableBitSet.builder();
-      for (int key: commonKeys) {
+      for (int key : commonKeys) {
         targetColumns.set(rel.getGroupSet().nth(key));
       }
 

core/src/main/java/org/apache/calcite/rel/metadata/RelMdPredicates.java

@@ -476,7 +476,7 @@ public RelOptPredicateList getPredicates(Intersect intersect, RelMetadataQuery m
         continue;
       }
 
-      for (RexNode pred: info.pulledUpPredicates) {
+      for (RexNode pred : info.pulledUpPredicates) {
         if (finalPredicates.stream().anyMatch(
             finalPred -> rexImplicationChecker.implies(finalPred, pred))) {
           // There's already a stricter predicate in finalPredicates,

core/src/main/java/org/apache/calcite/rel/rel2sql/RelToSqlConverter.java

@@ -501,16 +501,16 @@ public Result visit(Window e) {
     final RelNode input = e.getInput();
     final int inputFieldCount = input.getRowType().getFieldCount();
     final List<SqlNode> rexOvers = new ArrayList<>();
-    for (Window.Group group: e.groups) {
+    for (Window.Group group : e.groups) {
       rexOvers.addAll(builder.context.toSql(group, e.constants, inputFieldCount));
     }
     final List<SqlNode> selectList = new ArrayList<>();
 
-    for (RelDataTypeField field: input.getRowType().getFieldList()) {
+    for (RelDataTypeField field : input.getRowType().getFieldList()) {
       addSelect(selectList, builder.context.field(field.getIndex()), e.getRowType());
     }
 
-    for (SqlNode rexOver: rexOvers) {
+    for (SqlNode rexOver : rexOvers) {
       addSelect(selectList, rexOver, e.getRowType());
     }
 

core/src/main/java/org/apache/calcite/rel/rel2sql/SqlImplementor.java

@@ -943,10 +943,10 @@ public List<SqlNode> toSql(Window.Group group, ImmutableList<RexLiteral> constan
       final List<SqlNode> rexOvers = new ArrayList<>();
       final List<SqlNode> partitionKeys = new ArrayList<>();
       final List<SqlNode> orderByKeys = new ArrayList<>();
-      for (int partition: group.keys) {
+      for (int partition : group.keys) {
         partitionKeys.add(this.field(partition));
       }
-      for (RelFieldCollation collation: group.orderKeys.getFieldCollations()) {
+      for (RelFieldCollation collation : group.orderKeys.getFieldCollations()) {
         this.addOrderItem(orderByKeys, collation);
       }
       SqlLiteral isRows = SqlLiteral.createBoolean(group.isRows, POS);
@@ -955,7 +955,7 @@ public List<SqlNode> toSql(Window.Group group, ImmutableList<RexLiteral> constan
 
       final SqlLiteral allowPartial = null;
 
-      for (Window.RexWinAggCall winAggCall: group.aggCalls) {
+      for (Window.RexWinAggCall winAggCall : group.aggCalls) {
         SqlAggFunction aggFunction = (SqlAggFunction) winAggCall.getOperator();
         final SqlWindow sqlWindow =
                 SqlWindow.create(null, null,

core/src/main/java/org/apache/calcite/rel/rules/AggregateExpandDistinctAggregatesRule.java

@@ -463,9 +463,9 @@ private static void rewriteUsingGroupingSets(RelOptRuleCall call,
     // Get the base ordinal of filter args for different groupSets.
     final Map<Pair<ImmutableBitSet, Integer>, Integer> filters = new LinkedHashMap<>();
     int z = groupCount + distinctAggCalls.size();
-    for (ImmutableBitSet groupSet: groupSets) {
+    for (ImmutableBitSet groupSet : groupSets) {
       Set<Integer> filterArgList = distinctFilterArgMap.get(groupSet);
-      for (Integer filterArg: requireNonNull(filterArgList, "filterArgList")) {
+      for (Integer filterArg : requireNonNull(filterArgList, "filterArgList")) {
         filters.put(Pair.of(groupSet, filterArg), z);
         z += 1;
       }

core/src/main/java/org/apache/calcite/rel/rules/AggregateJoinRemoveRule.java

@@ -86,8 +86,9 @@ public AggregateJoinRemoveRule(
     boolean isLeftJoin = join.getJoinType() == JoinRelType.LEFT;
     int lower = isLeftJoin
         ? join.getLeft().getRowType().getFieldCount() : 0;
-    int upper = isLeftJoin ? join.getRowType().getFieldCount()
-        : join.getLeft().getRowType().getFieldCount();
+    int upper =
+        isLeftJoin ? join.getRowType().getFieldCount()
+            : join.getLeft().getRowType().getFieldCount();
 
     // Check whether the aggregate uses columns whose index is between
     // lower(included) and upper(excluded).

core/src/main/java/org/apache/calcite/rel/rules/AggregateProjectConstantToDummyJoinRule.java

@@ -65,7 +65,7 @@ private AggregateProjectConstantToDummyJoinRule(Config config) {
     final Aggregate aggregate = call.rel(0);
     final Project project = call.rel(1);
 
-    for (int groupKey: aggregate.getGroupSet().asList()) {
+    for (int groupKey : aggregate.getGroupSet().asList()) {
       if (groupKey >= aggregate.getRowType().getFieldCount()) {
         continue;
       }

core/src/main/java/org/apache/calcite/rel/rules/MinusToDistinctRule.java

@@ -149,8 +149,9 @@ public MinusToDistinctRule(Class<? extends Minus> minusClass,
 
     ImmutableList.Builder<RexNode> filters = ImmutableList.builder();
     for (int i = 0; i < branchCount; i++) {
-      SqlOperator operator = i == 0 ? SqlStdOperatorTable.GREATER_THAN
-          : SqlStdOperatorTable.EQUALS;
+      SqlOperator operator =
+          i == 0 ? SqlStdOperatorTable.GREATER_THAN
+              : SqlStdOperatorTable.EQUALS;
       filters.add(
           rexBuilder.makeCall(operator, relBuilder.field(originalFieldCnt + i),
           relBuilder.literal(new BigDecimal(0))));

core/src/main/java/org/apache/calcite/rel/rules/ProjectJoinJoinRemoveRule.java

@@ -89,7 +89,7 @@ public ProjectJoinJoinRemoveRule(
     int leftBottomChildSize = bottomJoin.getLeft().getRowType().getFieldCount();
 
     // Check whether the project uses columns in the right input of bottom join.
-    for (RexNode expr: project.getProjects()) {
+    for (RexNode expr : project.getProjects()) {
       if (RelOptUtil.InputFinder.bits(expr).asList().stream().anyMatch(
           i -> i >= leftBottomChildSize
               && i < bottomJoin.getRowType().getFieldCount())) {

core/src/main/java/org/apache/calcite/rel/rules/ProjectJoinRemoveRule.java

@@ -86,7 +86,7 @@ public ProjectJoinRemoveRule(
 
     // Check whether the project uses columns whose index is between
     // lower(included) and upper(excluded).
-    for (RexNode expr: project.getProjects()) {
+    for (RexNode expr : project.getProjects()) {
       if (RelOptUtil.InputFinder.bits(expr).asList().stream().anyMatch(
           i -> i >= lower && i < upper)) {
         return;

core/src/main/java/org/apache/calcite/rel/type/RelDataTypeFactoryImpl.java

@@ -262,7 +262,7 @@ private RelDataType createStructType(
       final List<RelDataType> types, SqlTypeName sqlTypeName) {
     assert sqlTypeName == SqlTypeName.ARRAY || sqlTypeName == SqlTypeName.MULTISET;
     boolean isNullable = false;
-    for (RelDataType type: types) {
+    for (RelDataType type : types) {
       if (type.getComponentType() == null) {
         return null;
       }
@@ -286,7 +286,7 @@ private RelDataType createStructType(
       final List<RelDataType> types, SqlTypeName sqlTypeName) {
     assert sqlTypeName == SqlTypeName.MAP;
     boolean isNullable = false;
-    for (RelDataType type: types) {
+    for (RelDataType type : types) {
       if (!(type instanceof MapSqlType)) {
         return null;
       }

core/src/main/java/org/apache/calcite/rex/RexProgram.java

@@ -250,7 +250,7 @@ public static RexProgram create(RelInput input) {
     final List<RexNode> projectRexNodes =
         requireNonNull(input.getExpressionList("projects"), "projects");
     final List<RexLocalRef> projects = new ArrayList<>(projectRexNodes.size());
-    for (RexNode rexNode: projectRexNodes) {
+    for (RexNode rexNode : projectRexNodes) {
       projects.add((RexLocalRef) rexNode);
     }
     final RelDataType inputType = input.getRowType("inputRowType");