Minor follow-up to #66933

docs/en/sql-reference/functions/string-replace-functions.md

@@ -20,10 +20,10 @@ overlay(s, replace, offset[, length])
 
 **Parameters**
 
-- `input`: A string type [String](../data-types/string.md).
+- `s`: A string type [String](../data-types/string.md).
 - `replace`: A string type [String](../data-types/string.md).
-- `offset`: An integer type [Int](../data-types/int-uint.md). If `offset` is negative, it is counted from the end of the `input` string.
-- `length`: Optional. An integer type [Int](../data-types/int-uint.md). `length` specifies the length of the snippet within input to be replaced. If `length` is not specified, the number of bytes removed from `input` equals the length of `replace`; otherwise `length` bytes are removed.
+- `offset`: An integer type [Int](../data-types/int-uint.md). If `offset` is negative, it is counted from the end of the string `s`.
+- `length`: Optional. An integer type [Int](../data-types/int-uint.md). `length` specifies the length of the snippet within the input string `s` to be replaced. If `length` is not specified, the number of bytes removed from `s` equals the length of `replace`; otherwise `length` bytes are removed.
 
 **Returned value**
 
@@ -32,22 +32,35 @@ overlay(s, replace, offset[, length])
 **Example**
 
 ```sql
-SELECT overlay('ClickHouse SQL', 'CORE', 12) AS res;
+SELECT overlay('My father is from Mexico.', 'mother', 4) AS res;
 ```
 
 Result:
 
 ```text
-┌─res─────────────┐
-│ ClickHouse CORE │
-└─────────────────┘
+┌─res──────────────────────┐
+│ My mother is from Mexico.│
+└──────────────────────────┘
+```
+
+```sql
+SELECT overlay('My father is from Mexico.', 'dad', 4, 6) AS res;
+```
+
+Result:
+
+```text
+┌─res───────────────────┐
+│ My dad is from Mexico.│
+└───────────────────────┘
 ```
 
 ## overlayUTF8
 
 Replace part of the string `input` with another string `replace`, starting at the 1-based index `offset`.
 
-Assumes that the string contains valid UTF-8 encoded text. If this assumption is violated, no exception is thrown and the result is undefined.
+Assumes that the string contains valid UTF-8 encoded text.
+If this assumption is violated, no exception is thrown and the result is undefined.
 
 **Syntax**
 
@@ -59,8 +72,8 @@ overlayUTF8(s, replace, offset[, length])
 
 - `s`: A string type [String](../data-types/string.md).
 - `replace`: A string type [String](../data-types/string.md).
-- `offset`: An integer type [Int](../data-types/int-uint.md). If `offset` is negative, it is counted from the end of the `input` string.
-- `length`: Optional. An integer type [Int](../data-types/int-uint.md). `length` specifies the length of the snippet within input to be replaced. If `length` is not specified, the number of characters removed from `input` equals the length of `replace`; otherwise `length` characters are removed.
+- `offset`: An integer type [Int](../data-types/int-uint.md). If `offset` is negative, it is counted from the end of the input string `s`.
+- `length`: Optional. An integer type [Int](../data-types/int-uint.md). `length` specifies the length of the snippet within the input string `s` to be replaced. If `length` is not specified, the number of characters removed from `s` equals the length of `replace`; otherwise `length` characters are removed.
 
 **Returned value**
 
@@ -69,15 +82,15 @@ overlayUTF8(s, replace, offset[, length])
 **Example**
 
 ```sql
-SELECT overlayUTF8('ClickHouse是一款OLAP数据库', '开源', 12, 2) AS res;
+SELECT overlay('Mein Vater ist aus Österreich.', 'der Türkei', 20) AS res;
 ```
 
 Result:
 
 ```text
-┌─res────────────────────────┐
-│ ClickHouse是开源OLAP数据库   │
-└────────────────────────────┘
+┌─res───────────────────────────┐
+│ Mein Vater ist aus der Türkei.│
+└───────────────────────────────┘
 ```
 
 ## replaceOne

src/Functions/overlay.cpp

@@ -1,12 +1,12 @@
 #include <Columns/ColumnConst.h>
 #include <Columns/ColumnString.h>
+#include <Common/StringUtils.h>
+#include <Common/UTF8Helpers.h>
 #include <DataTypes/DataTypeString.h>
 #include <Functions/FunctionFactory.h>
 #include <Functions/FunctionHelpers.h>
 #include <Functions/GatherUtils/Sources.h>
 #include <Functions/IFunction.h>
-#include <Common/StringUtils.h>
-#include <Common/UTF8Helpers.h>
 
 namespace DB
 {
@@ -16,8 +16,8 @@ namespace
 
 /// If 'is_utf8' - measure offset and length in code points instead of bytes.
 /// Syntax:
-/// - overlay(input, replace, offset[, length])
-/// - overlayUTF8(input, replace, offset[, length]) - measure offset and length in code points instead of bytes
+/// - overlay(s, replace, offset[, length])
+/// - overlayUTF8(s, replace, offset[, length]) - measure offset and length in code points instead of bytes
 template <bool is_utf8>
 class FunctionOverlay : public IFunction
 {
@@ -34,7 +34,7 @@ public:
     DataTypePtr getReturnTypeImpl(const ColumnsWithTypeAndName & arguments) const override
     {
         FunctionArgumentDescriptors mandatory_args{
-            {"input", static_cast<FunctionArgumentDescriptor::TypeValidator>(&isString), nullptr, "String"},
+            {"s", static_cast<FunctionArgumentDescriptor::TypeValidator>(&isString), nullptr, "String"},
             {"replace", static_cast<FunctionArgumentDescriptor::TypeValidator>(&isString), nullptr, "String"},
             {"offset", static_cast<FunctionArgumentDescriptor::TypeValidator>(&isNativeInteger), nullptr, "(U)Int8/16/32/64"},
         };
@@ -100,7 +100,6 @@ public:
             res_data.reserve(col_input_string->getChars().size());
         }
 
-
 #define OVERLAY_EXECUTE_CASE(HAS_FOUR_ARGS, OFFSET_IS_CONST, LENGTH_IS_CONST) \
     if (input_is_const && replace_is_const) \
         constantConstant<HAS_FOUR_ARGS, OFFSET_IS_CONST, LENGTH_IS_CONST>( \
@@ -186,7 +185,6 @@ public:
         return res_col;
     }
 
-
 private:
     /// input offset is 1-based, maybe negative
     /// output result is 0-based valid offset, within [0, input_size]
@@ -229,6 +227,7 @@ private:
         ColumnString::Chars & res_data,
         ColumnString::Offsets & res_offsets) const
     {
+        /// Free us from handling negative length in the code below
         if (has_four_args && length_is_const && const_length < 0)
         {
             constantConstant<true, offset_is_const, false>(
@@ -343,6 +342,7 @@ private:
         ColumnString::Chars & res_data,
         ColumnString::Offsets & res_offsets) const
     {
+        /// Free us from handling negative length in the code below
         if (has_four_args && length_is_const && const_length < 0)
         {
             vectorConstant<true, offset_is_const, false>(
@@ -461,6 +461,7 @@ private:
         ColumnString::Chars & res_data,
         ColumnString::Offsets & res_offsets) const
     {
+        /// Free us from handling negative length in the code below
         if (has_four_args && length_is_const && const_length < 0)
         {
             constantVector<true, offset_is_const, false>(
@@ -577,6 +578,7 @@ private:
         ColumnString::Chars & res_data,
         ColumnString::Offsets & res_offsets) const
     {
+        /// Free us from handling negative length in the code below
         if (has_four_args && length_is_const && const_length < 0)
         {
             vectorVector<true, offset_is_const, false>(

tests/queries/0_stateless/03205_overlay.sql

@@ -35,10 +35,10 @@ SELECT overlay('Spark SQL', materialize('ANSI '), materialize(7), materialize(0)
 SELECT overlay(materialize('Spark SQL'), materialize('ANSI '), materialize(7), materialize(0)), overlayUTF8(materialize('Spark SQL和CH'), materialize('ANSI '), materialize(7), materialize(0));
 
 SELECT 'Test with special offset values';
-WITH number - 12 AS offset SELECT offset, overlay('Spark SQL', '__', offset), overlayUTF8('Spark SQL和CH', '之', offset) FROM numbers(26);
+WITH number - 12 AS offset SELECT offset, overlay('Spark SQL', '__', offset), overlayUTF8('Spark SQL和CH', '之', offset) FROM numbers(26) ORDER BY number;
 
 SELECT 'Test with special length values';
-WITH number - 1 AS length SELECT length, overlay('Spark SQL', 'ANSI ', 7, length), overlayUTF8('Spark SQL和CH', 'ANSI ', 7, length) FROM numbers(8);
+WITH number - 1 AS length SELECT length, overlay('Spark SQL', 'ANSI ', 7, length), overlayUTF8('Spark SQL和CH', 'ANSI ', 7, length) FROM numbers(8) ORDER BY number;
 
 SELECT 'Test with special input and replace values';
 SELECT overlay('', '_', 6), overlayUTF8('', '_', 6);