Added documentation

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

@@ -28,7 +28,7 @@ The function also works for [arrays](array-functions.md#function-empty) or [UUID
 
 **Returned value**
 
--   Returns `1` for an empty string or `0` for a non-empty string. 
+-   Returns `1` for an empty string or `0` for a non-empty string.
 
 Type: [UInt8](../data-types/int-uint.md).
 
@@ -68,7 +68,7 @@ The function also works for [arrays](array-functions.md#function-notempty) or [U
 
 **Returned value**
 
--   Returns `1` for a non-empty string or `0` for an empty string string. 
+-   Returns `1` for a non-empty string or `0` for an empty string string.
 
 Type: [UInt8](../data-types/int-uint.md).
 
@@ -313,6 +313,30 @@ SELECT toValidUTF8('\x61\xF0\x80\x80\x80b');
 └───────────────────────┘
 ```
 
+## tokens {#tokens}
+
+Split string into tokens using non-alpha numeric ASCII characters as separators.
+
+**Arguments**
+
+-   `input_string` — Any set of bytes represented as the [String](../../sql-reference/data-types/string.md) data type object.
+
+**Returned value**
+
+-   The resulting array of tokens from input string.
+
+Type: [Array](../data-types/array.md).
+
+**Example**
+
+```
+SELECT tokens('test1,;\\ test2,;\\ test3,;\\   test4') AS tokens;
+```
+
+``` text
+SELECT tokens('test1,;\\ test2,;\\ test3,;\\   test4') AS tokens
+```
+
 ## repeat {#repeat}
 
 Repeats a string as many times as specified and concatenates the replicated values as a single string.

src/Functions/tokenExtractors.cpp

@@ -53,7 +53,7 @@ public:
         auto ngram_input_argument_type = WhichDataType(arguments[0].type);
         if (!ngram_input_argument_type.isStringOrFixedString())
             throw Exception(ErrorCodes::BAD_ARGUMENTS,
-                "Function {} second argument type should be String or FixedString. Actual {}",
+                "Function {} first argument type should be String or FixedString. Actual {}",
                 getName(),
                 arguments[0].type->getName());