branch-2.1: [fix](Nereids) fold constant for string function process emoji character by mistake #49087 (#49344)

pick: #49087 
Related PR: #40441

Problem Summary:

wrong calculation of emoji character length in some String function when
do constant folding in FE. For example:

select STRLEFT('😊😉👍', 2);

should return 😊😉, but fe return 😊 only when folding constant

fixed functions:
- left
- strleft
- right
- strright
- locate
- character_length
- split_by_string
- overlay
- replace_empty

fe/fe-core/src/main/java/org/apache/doris/catalog/BuiltinScalarFunctions.java

@@ -400,8 +400,6 @@ import org.apache.doris.nereids.trees.expressions.functions.scalar.StPolygonfrom
 import org.apache.doris.nereids.trees.expressions.functions.scalar.StX;
 import org.apache.doris.nereids.trees.expressions.functions.scalar.StY;
 import org.apache.doris.nereids.trees.expressions.functions.scalar.StartsWith;
-import org.apache.doris.nereids.trees.expressions.functions.scalar.StrLeft;
-import org.apache.doris.nereids.trees.expressions.functions.scalar.StrRight;
 import org.apache.doris.nereids.trees.expressions.functions.scalar.StrToDate;
 import org.apache.doris.nereids.trees.expressions.functions.scalar.Strcmp;
 import org.apache.doris.nereids.trees.expressions.functions.scalar.StructElement;
@@ -738,7 +736,7 @@ public class BuiltinScalarFunctions implements FunctionHelper {
             scalar(L2Distance.class, "l2_distance"),
             scalar(LastDay.class, "last_day"),
             scalar(Least.class, "least"),
-            scalar(Left.class, "left"),
+            scalar(Left.class, "left", "strleft"),
             scalar(Length.class, "length"),
             scalar(Crc32.class, "crc32"),
             scalar(Like.class, "like"),
@@ -820,7 +818,7 @@ public class BuiltinScalarFunctions implements FunctionHelper {
             scalar(Replace.class, "replace"),
             scalar(ReplaceEmpty.class, "replace_empty"),
             scalar(Reverse.class, "reverse"),
-            scalar(Right.class, "right"),
+            scalar(Right.class, "right", "strright"),
             scalar(Round.class, "round"),
             scalar(RoundBankers.class, "round_bankers"),
             scalar(Rpad.class, "rpad"),
@@ -880,8 +878,6 @@ public class BuiltinScalarFunctions implements FunctionHelper {
             scalar(StY.class, "st_y"),
             scalar(StartsWith.class, "starts_with"),
             scalar(Strcmp.class, "strcmp"),
-            scalar(StrLeft.class, "strleft"),
-            scalar(StrRight.class, "strright"),
             scalar(StrToDate.class, "str_to_date"),
             scalar(SubBitmap.class, "sub_bitmap"),
             scalar(SubReplace.class, "sub_replace"),

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

@@ -43,6 +43,7 @@ import org.apache.doris.nereids.types.ArrayType;
 import org.apache.doris.qe.ConnectContext;
 
 import com.google.common.collect.ImmutableList;
+import com.google.common.collect.Lists;
 
 import java.io.UnsupportedEncodingException;
 import java.net.MalformedURLException;
@@ -61,7 +62,7 @@ import java.util.regex.Pattern;
  * concat
  */
 public class StringArithmetic {
-    private static Expression castStringLikeLiteral(StringLikeLiteral first, String value) {
+    private static Literal castStringLikeLiteral(StringLikeLiteral first, String value) {
         if (first instanceof StringLiteral) {
             return new StringLiteral(value);
         } else if (first instanceof VarcharLiteral) {
@@ -80,7 +81,7 @@ public class StringArithmetic {
     }
 
     private static String substringImpl(String first, int second, int third) {
-        int stringLength = first.length();
+        int stringLength = first.codePointCount(0, first.length());
         if (stringLength == 0) {
             return "";
         }
@@ -102,8 +103,11 @@ public class StringArithmetic {
         } else {
             rightIndex = third + leftIndex;
         }
+        // at here leftIndex and rightIndex can not be exceeding boundary
+        int finalLeftIndex = first.codePointCount(0, (int) leftIndex);
+        int finalRightIndex = first.codePointCount(0, (int) rightIndex);
         // left index and right index are in integer range because of definition, so we can safely cast it to int
-        return first.substring((int) leftIndex, (int) rightIndex);
+        return first.substring(finalLeftIndex, finalRightIndex);
     }
 
     /**
@@ -294,12 +298,14 @@ public class StringArithmetic {
      */
     @ExecFunction(name = "left")
     public static Expression left(StringLikeLiteral first, IntegerLiteral second) {
+        int inputLength = first.getValue().codePointCount(0, first.getValue().length());
         if (second.getValue() <= 0) {
             return castStringLikeLiteral(first, "");
-        } else if (second.getValue() < first.getValue().length()) {
-            return castStringLikeLiteral(first, first.getValue().substring(0, second.getValue()));
-        } else {
+        } else if (second.getValue() >= inputLength) {
             return first;
+        } else {
+            int index = first.getValue().codePointCount(0, second.getValue());
+            return castStringLikeLiteral(first, first.getValue().substring(0, index));
         }
     }
 
@@ -308,17 +314,20 @@ public class StringArithmetic {
      */
     @ExecFunction(name = "right")
     public static Expression right(StringLikeLiteral first, IntegerLiteral second) {
-        if (second.getValue() < (- first.getValue().length()) || Math.abs(second.getValue()) == 0) {
+        int inputLength = first.getValue().codePointCount(0, first.getValue().length());
+        if (second.getValue() < (- inputLength) || Math.abs(second.getValue()) == 0) {
             return castStringLikeLiteral(first, "");
-        } else if (second.getValue() > first.getValue().length()) {
+        } else if (second.getValue() >= inputLength) {
             return first;
         } else {
-            if (second.getValue() > 0) {
+            if (second.getValue() >= 0) {
+                int index = first.getValue().codePointCount(0, second.getValue());
                 return castStringLikeLiteral(first, first.getValue().substring(
-                    first.getValue().length() - second.getValue(), first.getValue().length()));
+                    inputLength - index, inputLength));
             } else {
+                int index = first.getValue().codePointCount(Math.abs(second.getValue()) - 1, first.getValue().length());
                 return castStringLikeLiteral(first, first.getValue().substring(
-                    Math.abs(second.getValue()) - 1, first.getValue().length()));
+                    Math.abs(index) - 1, inputLength));
             }
         }
     }
@@ -338,7 +347,7 @@ public class StringArithmetic {
     public static Expression locate(StringLikeLiteral first, StringLikeLiteral second, IntegerLiteral third) {
         int result = second.getValue().indexOf(first.getValue()) + 1;
         if (third.getValue() <= 0 || !substringImpl(second.getValue(), third.getValue(),
-                second.getValue().length()).contains(first.getValue())) {
+                second.getValue().codePointCount(0, second.getValue().length())).contains(first.getValue())) {
             result = 0;
         }
         return new IntegerLiteral(result);
@@ -409,7 +418,7 @@ public class StringArithmetic {
      */
     @ExecFunction(name = "character_length")
     public static Expression characterLength(StringLikeLiteral first) {
-        return new IntegerLiteral(first.getValue().length());
+        return new IntegerLiteral(first.getValue().codePointCount(0, first.getValue().length()));
     }
 
     private static boolean isAlphabetic(char c) {
@@ -666,6 +675,23 @@ public class StringArithmetic {
         return new VarcharLiteral(sb.toString());
     }
 
+    /**
+     * split by char by empty string considering emoji
+     * @param str input string to be split
+     * @return ArrayLiteral
+     */
+    public static List<String> splitByGrapheme(StringLikeLiteral str) {
+        List<String> result = Lists.newArrayListWithExpectedSize(str.getValue().length());
+        int length = str.getValue().length();
+        for (int i = 0; i < length; ) {
+            int codePoint = str.getValue().codePointAt(i);
+            int charCount = Character.charCount(codePoint);
+            result.add(new String(new int[]{codePoint}, 0, 1));
+            i += charCount;
+        }
+        return result;
+    }
+
     /**
      * Executable arithmetic functions split_by_string
      */
@@ -674,11 +700,17 @@ public class StringArithmetic {
         if (first.getValue().isEmpty()) {
             return new ArrayLiteral(ImmutableList.of(), ArrayType.of(first.getDataType()));
         }
-        int limit = second.getValue().isEmpty() ? 0 : -1;
-        String[] result = first.getValue().split(Pattern.quote(second.getValue()), limit);
+        if (second.getValue().isEmpty()) {
+            List<Literal> result = Lists.newArrayListWithExpectedSize(first.getValue().length());
+            for (String resultStr : splitByGrapheme(first)) {
+                result.add(castStringLikeLiteral(first, resultStr));
+            }
+            return new ArrayLiteral(result);
+        }
+        String[] result = first.getValue().split(Pattern.quote(second.getValue()), -1);
         List<Literal> items = new ArrayList<>();
         for (String s : result) {
-            items.add((Literal) castStringLikeLiteral(first, s));
+            items.add(castStringLikeLiteral(first, s));
         }
         return new ArrayLiteral(items);
     }
@@ -775,60 +807,26 @@ public class StringArithmetic {
         }
     }
 
-    /**
-     * Executable arithmetic functions strLeft
-     */
-    @ExecFunction(name = "strleft")
-    public static Expression strLeft(StringLikeLiteral first, IntegerLiteral second) {
-        if (second.getValue() <= 0) {
-            return castStringLikeLiteral(first, "");
-        } else if (second.getValue() > first.getValue().length()) {
-            return first;
-        } else {
-            return castStringLikeLiteral(first, first.getValue().substring(0, second.getValue()));
-        }
-    }
-
-    /**
-     * Executable arithmetic functions strRight
-     */
-    @ExecFunction(name = "strright")
-    public static Expression strRight(StringLikeLiteral first, IntegerLiteral second) {
-        if (second.getValue() < (- first.getValue().length()) || Math.abs(second.getValue()) == 0) {
-            return castStringLikeLiteral(first, "");
-        } else if (second.getValue() > first.getValue().length()) {
-            return first;
-        } else {
-            if (second.getValue() > 0) {
-                return castStringLikeLiteral(first, first.getValue().substring(
-                    first.getValue().length() - second.getValue(), first.getValue().length()));
-            } else {
-                return castStringLikeLiteral(first, first.getValue().substring(
-                    Math.abs(second.getValue()) - 1, first.getValue().length()));
-            }
-        }
-    }
-
     /**
      * Executable arithmetic functions overlay
      */
     @ExecFunction(name = "overlay")
-    public static Expression overlay(StringLikeLiteral first,
-                                        IntegerLiteral second, IntegerLiteral third, StringLikeLiteral four) {
+    public static Expression overlay(StringLikeLiteral originStr,
+                                        IntegerLiteral pos, IntegerLiteral len, StringLikeLiteral insertStr) {
         StringBuilder sb = new StringBuilder();
-        if (second.getValue() <= 0 || second.getValue() > first.getValue().length()) {
-            return first;
+        int totalLength = originStr.getValue().codePointCount(0, originStr.getValue().length());
+        if (pos.getValue() <= 0 || pos.getValue() > totalLength) {
+            return originStr;
         } else {
-            if (third.getValue() < 0 || third.getValue() > (first.getValue().length() - third.getValue())) {
-                sb.append(first.getValue().substring(0, second.getValue() - 1));
-                sb.append(four.getValue());
-                return castStringLikeLiteral(first, sb.toString());
+            if (len.getValue() < 0 || len.getValue() > (totalLength - pos.getValue())) {
+                sb.append(substringImpl(originStr.getValue(), 1, pos.getValue() - 1));
+                sb.append(insertStr.getValue());
+                return castStringLikeLiteral(originStr, sb.toString());
             } else {
-                sb.append(first.getValue().substring(0, second.getValue() - 1));
-                sb.append(four.getValue());
-                sb.append(first.getValue().substring(second.getValue()
-                        + third.getValue() - 1, first.getValue().length()));
-                return castStringLikeLiteral(first, sb.toString());
+                sb.append(substringImpl(originStr.getValue(), 1, pos.getValue() - 1));
+                sb.append(insertStr.getValue());
+                sb.append(substringImpl(originStr.getValue(), pos.getValue() + len.getValue(), totalLength));
+                return castStringLikeLiteral(originStr, sb.toString());
             }
         }
     }
@@ -937,7 +935,7 @@ public class StringArithmetic {
      */
     @ExecFunction(name = "append_trailing_char_if_absent")
     public static Expression appendTrailingCharIfAbsent(StringLikeLiteral first, StringLikeLiteral second) {
-        if (second.getValue().length() != 1) {
+        if (second.getValue().codePointCount(0, second.getValue().length()) != 1) {
             return new NullLiteral(first.getDataType());
         }
         if (first.getValue().endsWith(second.getValue())) {
@@ -1001,6 +999,19 @@ public class StringArithmetic {
      */
     @ExecFunction(name = "replace_empty")
     public static Expression replaceEmpty(StringLikeLiteral first, StringLikeLiteral second, StringLikeLiteral third) {
+        if (second.getValue().isEmpty()) {
+            if (first.getValue().isEmpty()) {
+                return castStringLikeLiteral(first, third.getValue());
+            }
+            List<String> inputs = splitByGrapheme(first);
+            StringBuilder sb = new StringBuilder();
+            sb.append(third.getValue());
+            for (String input : inputs) {
+                sb.append(input);
+                sb.append(third.getValue());
+            }
+            return castStringLikeLiteral(first, sb.toString());
+        }
         return castStringLikeLiteral(first, first.getValue().replace(second.getValue(), third.getValue()));
     }
 

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

@@ -1,70 +0,0 @@
-// Licensed to the Apache Software Foundation (ASF) under one
-// or more contributor license agreements.  See the NOTICE file
-// distributed with this work for additional information
-// regarding copyright ownership.  The ASF licenses this file
-// to you under the Apache License, Version 2.0 (the
-// "License"); you may not use this file except in compliance
-// with the License.  You may obtain a copy of the License at
-//
-//   http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing,
-// software distributed under the License is distributed on an
-// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
-// KIND, either express or implied.  See the License for the
-// specific language governing permissions and limitations
-// under the License.
-
-package org.apache.doris.nereids.trees.expressions.functions.scalar;
-
-import org.apache.doris.catalog.FunctionSignature;
-import org.apache.doris.nereids.trees.expressions.Expression;
-import org.apache.doris.nereids.trees.expressions.functions.ExplicitlyCastableSignature;
-import org.apache.doris.nereids.trees.expressions.functions.PropagateNullable;
-import org.apache.doris.nereids.trees.expressions.shape.BinaryExpression;
-import org.apache.doris.nereids.trees.expressions.visitor.ExpressionVisitor;
-import org.apache.doris.nereids.types.IntegerType;
-import org.apache.doris.nereids.types.StringType;
-import org.apache.doris.nereids.types.VarcharType;
-
-import com.google.common.base.Preconditions;
-import com.google.common.collect.ImmutableList;
-
-import java.util.List;
-
-/**
- * ScalarFunction 'strleft'. This class is generated by GenerateFunction.
- */
-public class StrLeft extends ScalarFunction
-        implements BinaryExpression, ExplicitlyCastableSignature, PropagateNullable {
-
-    public static final List<FunctionSignature> SIGNATURES = ImmutableList.of(
-            FunctionSignature.ret(VarcharType.SYSTEM_DEFAULT).args(VarcharType.SYSTEM_DEFAULT, IntegerType.INSTANCE),
-            FunctionSignature.ret(StringType.INSTANCE).args(StringType.INSTANCE, IntegerType.INSTANCE));
-
-    /**
-     * constructor with 2 arguments.
-     */
-    public StrLeft(Expression arg0, Expression arg1) {
-        super("strleft", arg0, arg1);
-    }
-
-    /**
-     * withChildren.
-     */
-    @Override
-    public StrLeft withChildren(List<Expression> children) {
-        Preconditions.checkArgument(children.size() == 2);
-        return new StrLeft(children.get(0), children.get(1));
-    }
-
-    @Override
-    public List<FunctionSignature> getSignatures() {
-        return SIGNATURES;
-    }
-
-    @Override
-    public <R, C> R accept(ExpressionVisitor<R, C> visitor, C context) {
-        return visitor.visitStrLeft(this, context);
-    }
-}

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

@@ -1,70 +0,0 @@
-// Licensed to the Apache Software Foundation (ASF) under one
-// or more contributor license agreements.  See the NOTICE file
-// distributed with this work for additional information
-// regarding copyright ownership.  The ASF licenses this file
-// to you under the Apache License, Version 2.0 (the
-// "License"); you may not use this file except in compliance
-// with the License.  You may obtain a copy of the License at
-//
-//   http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing,
-// software distributed under the License is distributed on an
-// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
-// KIND, either express or implied.  See the License for the
-// specific language governing permissions and limitations
-// under the License.
-
-package org.apache.doris.nereids.trees.expressions.functions.scalar;
-
-import org.apache.doris.catalog.FunctionSignature;
-import org.apache.doris.nereids.trees.expressions.Expression;
-import org.apache.doris.nereids.trees.expressions.functions.ExplicitlyCastableSignature;
-import org.apache.doris.nereids.trees.expressions.functions.PropagateNullable;
-import org.apache.doris.nereids.trees.expressions.shape.BinaryExpression;
-import org.apache.doris.nereids.trees.expressions.visitor.ExpressionVisitor;
-import org.apache.doris.nereids.types.IntegerType;
-import org.apache.doris.nereids.types.StringType;
-import org.apache.doris.nereids.types.VarcharType;
-
-import com.google.common.base.Preconditions;
-import com.google.common.collect.ImmutableList;
-
-import java.util.List;
-
-/**
- * ScalarFunction 'strright'. This class is generated by GenerateFunction.
- */
-public class StrRight extends ScalarFunction
-        implements BinaryExpression, ExplicitlyCastableSignature, PropagateNullable {
-
-    public static final List<FunctionSignature> SIGNATURES = ImmutableList.of(
-            FunctionSignature.ret(VarcharType.SYSTEM_DEFAULT).args(VarcharType.SYSTEM_DEFAULT, IntegerType.INSTANCE),
-            FunctionSignature.ret(StringType.INSTANCE).args(StringType.INSTANCE, IntegerType.INSTANCE));
-
-    /**
-     * constructor with 2 arguments.
-     */
-    public StrRight(Expression arg0, Expression arg1) {
-        super("strright", arg0, arg1);
-    }
-
-    /**
-     * withChildren.
-     */
-    @Override
-    public StrRight withChildren(List<Expression> children) {
-        Preconditions.checkArgument(children.size() == 2);
-        return new StrRight(children.get(0), children.get(1));
-    }
-
-    @Override
-    public List<FunctionSignature> getSignatures() {
-        return SIGNATURES;
-    }
-
-    @Override
-    public <R, C> R accept(ExpressionVisitor<R, C> visitor, C context) {
-        return visitor.visitStrRight(this, context);
-    }
-}

fe/fe-core/src/main/java/org/apache/doris/nereids/trees/expressions/visitor/ScalarFunctionVisitor.java

@@ -398,8 +398,6 @@ import org.apache.doris.nereids.trees.expressions.functions.scalar.StPolygonfrom
 import org.apache.doris.nereids.trees.expressions.functions.scalar.StX;
 import org.apache.doris.nereids.trees.expressions.functions.scalar.StY;
 import org.apache.doris.nereids.trees.expressions.functions.scalar.StartsWith;
-import org.apache.doris.nereids.trees.expressions.functions.scalar.StrLeft;
-import org.apache.doris.nereids.trees.expressions.functions.scalar.StrRight;
 import org.apache.doris.nereids.trees.expressions.functions.scalar.StrToDate;
 import org.apache.doris.nereids.trees.expressions.functions.scalar.Strcmp;
 import org.apache.doris.nereids.trees.expressions.functions.scalar.StructElement;
@@ -1958,14 +1956,6 @@ public interface ScalarFunctionVisitor<R, C> {
         return visitScalarFunction(startsWith, context);
     }
 
-    default R visitStrLeft(StrLeft strLeft, C context) {
-        return visitScalarFunction(strLeft, context);
-    }
-
-    default R visitStrRight(StrRight strRight, C context) {
-        return visitScalarFunction(strRight, context);
-    }
-
     default R visitStrToDate(StrToDate strToDate, C context) {
         return visitScalarFunction(strToDate, context);
     }

fe/fe-core/src/test/java/org/apache/doris/nereids/rules/expression/FoldConstantTest.java

@@ -38,6 +38,7 @@ import org.apache.doris.nereids.trees.expressions.functions.scalar.Asin;
 import org.apache.doris.nereids.trees.expressions.functions.scalar.Bin;
 import org.apache.doris.nereids.trees.expressions.functions.scalar.BitCount;
 import org.apache.doris.nereids.trees.expressions.functions.scalar.Ceil;
+import org.apache.doris.nereids.trees.expressions.functions.scalar.CharacterLength;
 import org.apache.doris.nereids.trees.expressions.functions.scalar.Coalesce;
 import org.apache.doris.nereids.trees.expressions.functions.scalar.ConvertTz;
 import org.apache.doris.nereids.trees.expressions.functions.scalar.Cos;
@@ -47,16 +48,21 @@ import org.apache.doris.nereids.trees.expressions.functions.scalar.Exp;
 import org.apache.doris.nereids.trees.expressions.functions.scalar.Floor;
 import org.apache.doris.nereids.trees.expressions.functions.scalar.FromUnixtime;
 import org.apache.doris.nereids.trees.expressions.functions.scalar.HoursAdd;
+import org.apache.doris.nereids.trees.expressions.functions.scalar.Left;
 import org.apache.doris.nereids.trees.expressions.functions.scalar.Ln;
+import org.apache.doris.nereids.trees.expressions.functions.scalar.Locate;
 import org.apache.doris.nereids.trees.expressions.functions.scalar.Log;
 import org.apache.doris.nereids.trees.expressions.functions.scalar.MinutesAdd;
 import org.apache.doris.nereids.trees.expressions.functions.scalar.Power;
+import org.apache.doris.nereids.trees.expressions.functions.scalar.ReplaceEmpty;
+import org.apache.doris.nereids.trees.expressions.functions.scalar.Right;
 import org.apache.doris.nereids.trees.expressions.functions.scalar.Round;
 import org.apache.doris.nereids.trees.expressions.functions.scalar.SecondsAdd;
 import org.apache.doris.nereids.trees.expressions.functions.scalar.Sign;
 import org.apache.doris.nereids.trees.expressions.functions.scalar.Sin;
 import org.apache.doris.nereids.trees.expressions.functions.scalar.Sqrt;
 import org.apache.doris.nereids.trees.expressions.functions.scalar.StrToDate;
+import org.apache.doris.nereids.trees.expressions.functions.scalar.Substring;
 import org.apache.doris.nereids.trees.expressions.functions.scalar.Tan;
 import org.apache.doris.nereids.trees.expressions.functions.scalar.ToDays;
 import org.apache.doris.nereids.trees.expressions.functions.scalar.UnixTimestamp;
@@ -332,6 +338,92 @@ class FoldConstantTest extends ExpressionRewriteTestHelper {
         AppendTrailingCharIfAbsent a = new AppendTrailingCharIfAbsent(StringLiteral.of("1"), StringLiteral.of("3"));
         rewritten = executor.rewrite(a, context);
         Assertions.assertEquals(new StringLiteral("13"), rewritten);
+
+        Left left = new Left(StringLiteral.of("hello world"), IntegerLiteral.of(5));
+        rewritten = executor.rewrite(left, context);
+        Assertions.assertEquals(new StringLiteral("hello"), rewritten);
+        left = new Left(StringLiteral.of("test"), IntegerLiteral.of(10));
+        rewritten = executor.rewrite(left, context);
+        Assertions.assertEquals(new StringLiteral("test"), rewritten);
+        left = new Left(StringLiteral.of("data"), IntegerLiteral.of(0));
+        rewritten = executor.rewrite(left, context);
+        Assertions.assertEquals(new StringLiteral(""), rewritten);
+        left = new Left(StringLiteral.of("data"), IntegerLiteral.of(-3));
+        rewritten = executor.rewrite(left, context);
+        Assertions.assertEquals(new StringLiteral(""), rewritten);
+
+        Right right = new Right(StringLiteral.of("hello world"), IntegerLiteral.of(5));
+        rewritten = executor.rewrite(right, context);
+        Assertions.assertEquals(new StringLiteral("world"), rewritten);
+        right = new Right(StringLiteral.of("test"), IntegerLiteral.of(10));
+        rewritten = executor.rewrite(right, context);
+        Assertions.assertEquals(new StringLiteral("test"), rewritten);
+        right = new Right(StringLiteral.of("data"), IntegerLiteral.of(0));
+        rewritten = executor.rewrite(right, context);
+        Assertions.assertEquals(new StringLiteral(""), rewritten);
+        right = new Right(StringLiteral.of("data"), IntegerLiteral.of(-3));
+        rewritten = executor.rewrite(right, context);
+        Assertions.assertEquals(new StringLiteral("ata"), rewritten);
+
+        Substring substr = new Substring(
+                StringLiteral.of("database"),
+                IntegerLiteral.of(1),
+                IntegerLiteral.of(4)
+        );
+        rewritten = executor.rewrite(substr, context);
+        Assertions.assertEquals(new StringLiteral("data"), rewritten);
+        substr = new Substring(
+            StringLiteral.of("database"),
+                IntegerLiteral.of(-4),
+                IntegerLiteral.of(4)
+        );
+        rewritten = executor.rewrite(substr, context);
+        Assertions.assertEquals(new StringLiteral("base"), rewritten);
+        substr = new Substring(
+                StringLiteral.of("example"),
+                IntegerLiteral.of(3),
+                IntegerLiteral.of(10)
+        );
+        rewritten = executor.rewrite(substr, context);
+        Assertions.assertEquals(new StringLiteral("ample"), rewritten);
+
+        Locate locate = new Locate(
+                StringLiteral.of("world"),
+                StringLiteral.of("hello world")
+        );
+        rewritten = executor.rewrite(locate, context);
+        Assertions.assertEquals(new IntegerLiteral(7), rewritten);
+        locate = new Locate(
+                StringLiteral.of("test"),
+                StringLiteral.of("hello world")
+        );
+        rewritten = executor.rewrite(locate, context);
+        Assertions.assertEquals(new IntegerLiteral(0), rewritten);
+        locate = new Locate(
+                StringLiteral.of("l"),
+                StringLiteral.of("hello world"),
+                IntegerLiteral.of(3)
+        );
+        rewritten = executor.rewrite(locate, context);
+        Assertions.assertEquals(new IntegerLiteral(3), rewritten);
+
+        CharacterLength len = new CharacterLength(StringLiteral.of("hello"));
+        rewritten = executor.rewrite(len, context);
+        Assertions.assertEquals(new IntegerLiteral(5), rewritten);
+        len = new CharacterLength(StringLiteral.of(""));
+        rewritten = executor.rewrite(len, context);
+        Assertions.assertEquals(new IntegerLiteral(0), rewritten);
+        len = new CharacterLength(StringLiteral.of("😊"));
+        rewritten = executor.rewrite(len, context);
+        Assertions.assertEquals(new IntegerLiteral(1), rewritten);
+
+        ReplaceEmpty replace = new ReplaceEmpty(
+                StringLiteral.of(""),
+                StringLiteral.of(""),
+                StringLiteral.of("default")
+        );
+        rewritten = executor.rewrite(replace, context);
+        Assertions.assertEquals(new StringLiteral("default"), rewritten);
     }
 
     @Test

regression-test/suites/nereids_p0/expression/fold_constant/fold_constant_string_arithmatic.groovy

@@ -259,7 +259,6 @@ suite("fold_constant_string_arithmatic") {
     testFoldConst("select initcap('semi;test')")
     testFoldConst("select initcap('quote''test')")
     testFoldConst("select initcap('slash/test')")
-    testFoldConst("select initcap('back\slash')")
     testFoldConst("select initcap('emoji<d83d><dc3c>test')")
     testFoldConst("select initcap('数字123test')")
     testFoldConst("select initcap(' leading space')")
@@ -498,7 +497,7 @@ suite("fold_constant_string_arithmatic") {
     testFoldConst("select null_or_empty(NULL)")
     testFoldConst("select null_or_empty('\b')")
     testFoldConst("select null_or_empty(' \b')")
-
+    
     // parse_url
     testFoldConst("select parse_url(cast('http://www.example.com/path?query=abc' as string), cast('HOST' as string))")
     testFoldConst("select parse_url('http://www.example.com/path?query=abc', 'HOST')")
@@ -934,6 +933,60 @@ suite("fold_constant_string_arithmatic") {
     testFoldConst("select strleft(' Hello World', 5)")
     testFoldConst("select strleft('Hello World ', 50)")
     testFoldConst("select strleft(NULL, 1)")
+    testFoldConst("select strleft('😊😉👍', 2)")
+    testFoldConst("select strleft('αβγδ', 3)")
+    testFoldConst("select strleft('你好世界', 4)")
+    testFoldConst("select strleft('こんにちは世界', 5)")
+    testFoldConst("select strleft('안녕하세요', 3)")
+    testFoldConst("select strleft('привет', 4)")
+    testFoldConst("select strleft('שלום', 3)")
+    testFoldConst("select strleft('😊😉👍😊😉', 4)")
+    testFoldConst("select strleft('αβγδεζ', 4)")
+    testFoldConst("select strleft('你好呀，世界', 6)")
+    testFoldConst("select strleft('こんにちは、素晴らしい一日', 7)")
+    testFoldConst("select strleft('안녕하세요 여러분', 5)")
+    testFoldConst("select strleft('привет мир', 6)")
+    testFoldConst("select strleft('שלום עולם', 4)")
+    testFoldConst("select strleft(null, 2)")
+    testFoldConst("select strleft('😊😉👍😊😉👍', 0)")
+    testFoldConst("select strleft('αβγδεζη', -1)")
+    testFoldConst("select strleft('你好，美好的一天', -2)")
+    testFoldConst("select strleft('こんにちは、素晴らしい一日', -3)")
+    testFoldConst("select strleft('안녕하세요 여러분 안녕히가세요', -4)")
+    testFoldConst("select strleft('привет всем друзьям', -5)")
+    testFoldConst("select strleft('שלום לכל החברים', -3)")
+    testFoldConst("select strleft('', 2)")
+    testFoldConst("select strleft('😊😉', -1)")
+    testFoldConst("select strleft('αβ', 0)")
+    testFoldConst("select strleft('你好', -1)")
+    testFoldConst("select strleft('こんにちは', 0)")
+    testFoldConst("select strleft('안녕하세요', -1)")
+    testFoldConst("select strleft('привет', 0)")
+    testFoldConst("select strleft('שלום', -1)")
+    testFoldConst("select strleft('😊😉👍😊😉👍😊', 5)")
+    testFoldConst("select strleft('αβγδεζηθ', 5)")
+    testFoldConst("select strleft('你好，世界！欢迎', 6)")
+    testFoldConst("select strleft('こんにちは、世界！ようこそ', 7)")
+    testFoldConst("select strleft('안녕하세요 세계!', 5)")
+    testFoldConst("select strleft('привет, мир!', 6)")
+    testFoldConst("select strleft('שלום עולם!', 4)")
+    testFoldConst("select strleft('😊😉👍😊😉👍😊😉', 6)")
+    testFoldConst("select strleft('αβγδεζηθι', 6)")
+    testFoldConst("select strleft('你好呀，美好的世界', 7)")
+    testFoldConst("select strleft('こんにちは、素晴らしい世界よ', 8)")
+    testFoldConst("select strleft('안녕하세요, 아름다운 세상', 7)")
+    testFoldConst("select strleft('привет, прекрасный мир', 8)")
+    testFoldConst("select strleft('שלום לעולם יפה', 5)")
+    testFoldConst("select strleft('', -1)")
+    testFoldConst("select strleft('😊😉', 0)")
+    testFoldConst("select strleft('αβ', -1)")
+    testFoldConst("select strleft('你好', 0)")
+    testFoldConst("select strleft('こんにちは', -1)")
+    testFoldConst("select strleft('안녕하세요', 0)")
+    testFoldConst("select strleft('привет', -1)")
+    testFoldConst("select strleft('שלום', 0)")
+    testFoldConst("select strleft('привет', 2147483647)")
+    testFoldConst("select strleft('привет', 2147483648)")
 
     // strright
     testFoldConst("select strright('good morning', NULL)")
@@ -944,7 +997,61 @@ suite("fold_constant_string_arithmatic") {
     testFoldConst("select strright(' Hello World', 5)")
     testFoldConst("select strright('Hello World  ', 5)")
     testFoldConst("select strright(NULL, 1)")
-
+    testFoldConst("select strright('😊😉👍', 2)")
+    testFoldConst("select strright('αβγδ', 3)")
+    testFoldConst("select strright('你好世界', 2)")
+    testFoldConst("select strright('こんにちは世界', 3)")
+    testFoldConst("select strright('안녕하세요', 3)")
+    testFoldConst("select strright('привет', 4)")
+    testFoldConst("select strright('שלום', 3)")
+    testFoldConst("select strright('😊😉👍😊😉', 4)")
+    testFoldConst("select strright('αβγδεζ', 4)")
+    testFoldConst("select strright('你好呀，世界', 6)")
+    testFoldConst("select strright('こんにちは、素晴らしい一日', 7)")
+    testFoldConst("select strright('안녕하세요 여러분', 5)")
+    testFoldConst("select strright('привет мир', 6)")
+    testFoldConst("select strright('שלום לכל החברים', 10)")
+    testFoldConst("select strright(null, 2)")
+    testFoldConst("select strright('😊😉👍😊😉👍', 0)")
+    testFoldConst("select strright('αβγδεζη', -1)")
+    testFoldConst("select strright('你好，美好的一天', -2)")
+    testFoldConst("select strright('こんにちは、素晴らしい一日', -3)")
+    testFoldConst("select strright('안녕하세요 여러분 안녕히가세요', -4)")
+    testFoldConst("select strright('привет всем друзьям', -5)")
+    testFoldConst("select strright('שלום עולם!', -3)")
+    testFoldConst("select strright('', 2)")
+    testFoldConst("select strright('😊😉', -1)")
+    testFoldConst("select strright('αβ', 0)")
+    testFoldConst("select strright('你好', -1)")
+    testFoldConst("select strright('こんにちは', 0)")
+    testFoldConst("select strright('안녕하세요', -1)")
+    testFoldConst("select strright('привет', 0)")
+    testFoldConst("select strright('שלום', -1)")
+    testFoldConst("select strright('😊😉👍😊😉👍😊', 5)")
+    testFoldConst("select strright('αβγδεζηθ', 5)")
+    testFoldConst("select strright('你好，世界！欢迎', 6)")
+    testFoldConst("select strright('こんにちは、世界！ようこそ', 7)")
+    testFoldConst("select strright('안녕하세요 세계!', 5)")
+    testFoldConst("select strright('привет, мир!', 6)")
+    testFoldConst("select strright('שלום עולם!', 4)")
+    testFoldConst("select strright('😊😉👍😊😉👍😊😉', 6)")
+    testFoldConst("select strright('αβγδεζηθι', 6)")
+    testFoldConst("select strright('你好呀，美好的世界', 7)")
+    testFoldConst("select strright('こんにちは、素晴らしい世界よ', 8)")
+    testFoldConst("select strright('안녕하세요, 아름다운 세상', 7)")
+    testFoldConst("select strright('привет, прекрасный мир', 8)")
+    testFoldConst("select strright('שלום לעולם יפה', 5)")
+    testFoldConst("select strright('', -1)")
+    testFoldConst("select strright('😊😉', 0)")
+    testFoldConst("select strright('αβ', -1)")
+    testFoldConst("select strright('你好', 0)")
+    testFoldConst("select strright('こんにちは', -1)")
+    testFoldConst("select strright('안녕하세요', 0)")
+    testFoldConst("select strright('привет', -1)")
+    testFoldConst("select strright('שלום', 0)")
+    testFoldConst("select strright('привет', 2147483647)")
+    testFoldConst("select strright('привет', 2147483648)")
+    
     // sub_replace
     testFoldConst("select sub_replace(CAST('doris' AS STRING), CAST('***' AS STRING), 1, 2)")
     testFoldConst("select sub_replace(CAST('doris' AS STRING), CAST('***' AS STRING), 1, 2)")
@@ -1602,4 +1709,9 @@ suite("fold_constant_string_arithmatic") {
     testFoldConst("select extract_url_parameter('http://user:pwd@www.baidu.com?🌍=b&c=d&e=f&g=h&i=j&k=l', '')")
     testFoldConst("select extract_url_parameter('http://user:pwd@www.baidu.com?🌍=b&c=d&e=f&g=h&i=j&k=l', null)")
 
+    // emoji
+    testFoldConst("select replace_empty('😀abc', '', 'def')")
+    testFoldConst("select split_by_string('a😁a😁a', '')")
+    testFoldConst("select character_length('a😁a😁a')")
+    testFoldConst("select replace_empty('a😁a😁a', '', '2')")
 }