[enhancement](chore)add single space separator rule to fe check style (apache#12354)

Some times, our code use more than one space as separator by mistake. This PR add a CheckStyle rule SingleSpaceSeparator to check that for Nereids.

Author: morrySnow

fe/check/checkstyle/checkstyle.xml

@@ -391,6 +391,7 @@ under the License.
             <property name="tokens" value="METHOD_REF"/>
             <property name="option" value="nl"/>
         </module>
+        <module name="SingleSpaceSeparator"/>
         <module name="WhitespaceAfter">
             <property name="tokens"
                       value="COMMA, SEMI, TYPECAST, LITERAL_IF, LITERAL_ELSE,

fe/check/checkstyle/suppressions.xml

@@ -47,6 +47,7 @@ under the License.
     <!-- other -->
     <suppress files="org[\\/]apache[\\/]doris[\\/](?!nereids)[^\\/]+[\\/]|PaloFe\.java" checks="DeclarationOrder" />
     <suppress files="org[\\/]apache[\\/]doris[\\/](?!nereids)[^\\/]+[\\/]|PaloFe\.java" checks="OverloadMethodsDeclarationOrder" />
+    <suppress files="org[\\/]apache[\\/]doris[\\/](?!nereids)[^\\/]+[\\/]|PaloFe\.java" checks="SingleSpaceSeparator" />
     <suppress files="org[\\/]apache[\\/]doris[\\/](?!nereids)[^\\/]+[\\/]|PaloFe\.java" checks="VariableDeclarationUsageDistance" />
 
     <!-- exclude rules for special files -->

fe/fe-core/src/main/java/org/apache/doris/nereids/analyzer/UnboundFunction.java

@@ -64,13 +64,13 @@ public String toSql() throws UnboundException {
         String params = children.stream()
                 .map(Expression::toSql)
                 .collect(Collectors.joining(", "));
-        return name + "(" + (isDistinct ? "DISTINCT " : "")  + params + ")";
+        return name + "(" + (isDistinct ? "DISTINCT " : "") + params + ")";
     }
 
     @Override
     public String toString() {
         String params = Joiner.on(", ").join(children);
-        return "'" + name + "(" + (isDistinct ? "DISTINCT " : "")  + params + ")";
+        return "'" + name + "(" + (isDistinct ? "DISTINCT " : "") + params + ")";
     }
 
     @Override

fe/fe-core/src/main/java/org/apache/doris/nereids/glue/translator/ExpressionTranslator.java

@@ -265,7 +265,7 @@ public Expr visitBoundFunction(BoundFunction function, PlanTranslatorContext con
 
     @Override
     public Expr visitBinaryArithmetic(BinaryArithmetic binaryArithmetic, PlanTranslatorContext context) {
-        ArithmeticExpr arithmeticExpr =  new ArithmeticExpr(binaryArithmetic.getLegacyOperator(),
+        ArithmeticExpr arithmeticExpr = new ArithmeticExpr(binaryArithmetic.getLegacyOperator(),
                 binaryArithmetic.child(0).accept(this, context),
                 binaryArithmetic.child(1).accept(this, context));
         return arithmeticExpr;

fe/fe-core/src/main/java/org/apache/doris/nereids/glue/translator/PhysicalPlanTranslator.java

@@ -356,7 +356,7 @@ public PlanFragment visitPhysicalHashJoin(PhysicalHashJoin<Plan, Plan> hashJoin,
 
         TupleDescriptor leftChildOutputTupleDesc = leftPlanRoot.getOutputTupleDesc();
         TupleDescriptor leftTuple =
-                leftChildOutputTupleDesc != null ? leftChildOutputTupleDesc :  context.getTupleDesc(leftPlanRoot);
+                leftChildOutputTupleDesc != null ? leftChildOutputTupleDesc : context.getTupleDesc(leftPlanRoot);
         TupleDescriptor rightChildOutputTupleDesc = rightPlanRoot.getOutputTupleDesc();
         TupleDescriptor rightTuple =
                 rightChildOutputTupleDesc != null ? rightChildOutputTupleDesc : context.getTupleDesc(rightPlanRoot);

fe/fe-core/src/main/java/org/apache/doris/nereids/pattern/generator/LogicalLeafPatternGenerator.java

@@ -32,7 +32,7 @@ public LogicalLeafPatternGenerator(PatternGeneratorAnalyzer analyzer,
 
     @Override
     public String genericType() {
-        return  "<" + opType.name + ">";
+        return "<" + opType.name + ">";
     }
 
     @Override

fe/fe-core/src/main/java/org/apache/doris/nereids/pattern/generator/PatternGenerator.java

@@ -275,7 +275,7 @@ public String generateTypePattern(String patterName, String className,
                 childrenPattern = ", " + childrenPattern;
             }
 
-            String pattern =  "default " + methodGeneric + "\n"
+            String pattern = "default " + methodGeneric + "\n"
                     + "PatternDescriptor" + genericParam + "\n"
                     + "        " + patterName + "(" + methodParam + ") {\n"
                     + "    return new PatternDescriptor" + genericParam + "(\n"

fe/fe-core/src/main/java/org/apache/doris/nereids/rules/expression/rewrite/rules/SimplifyNotExprRule.java

@@ -51,15 +51,15 @@ public Expression visitNot(Not not, ExpressionRewriteContext context) {
         Expression child = not.child();
         if (child instanceof ComparisonPredicate) {
             ComparisonPredicate cp = (ComparisonPredicate) not.child();
-            Expression left =  rewrite(cp.left(), context);
+            Expression left = rewrite(cp.left(), context);
             Expression right = rewrite(cp.right(), context);
 
             // TODO: visit concrete class instead of `instanceof`.
             if (child instanceof GreaterThan) {
                 return new LessThanEqual(left, right);
             } else if (child instanceof GreaterThanEqual) {
                 return new LessThan(left, right);
-            } else  if (child instanceof LessThan) {
+            } else if (child instanceof LessThan) {
                 return new GreaterThanEqual(left, right);
             } else if (child instanceof LessThanEqual) {
                 return new GreaterThan(left, right);
@@ -68,7 +68,7 @@ public Expression visitNot(Not not, ExpressionRewriteContext context) {
             }
         } else if (child instanceof CompoundPredicate) {
             CompoundPredicate cp = (CompoundPredicate) not.child();
-            Expression left =  rewrite(new Not(cp.left()), context);
+            Expression left = rewrite(new Not(cp.left()), context);
             Expression right = rewrite(new Not(cp.right()), context);
             return cp.flip(left, right);
         }

fe/fe-core/src/main/java/org/apache/doris/nereids/rules/rewrite/logical/MergeConsecutiveFilters.java

@@ -42,7 +42,7 @@
  *                   |
  *                 scan
  */
-public class MergeConsecutiveFilters  extends OneRewriteRuleFactory {
+public class MergeConsecutiveFilters extends OneRewriteRuleFactory {
     @Override
     public Rule build() {
         return logicalFilter(logicalFilter()).then(filter -> {

fe/fe-core/src/main/java/org/apache/doris/nereids/trees/expressions/functions/WeekOfYear.java

@@ -34,7 +34,7 @@
 /**
  * weekOfYear function
  */
-public class WeekOfYear  extends BoundFunction implements UnaryExpression, ImplicitCastInputTypes {
+public class WeekOfYear extends BoundFunction implements UnaryExpression, ImplicitCastInputTypes {
 
     private static final List<AbstractDataType> EXPECTED_INPUT_TYPES = ImmutableList.of(
             new TypeCollection(DateTimeType.INSTANCE)