Add documentation to source code

Author: Blargian

src/Functions/array/arrayEnumerate.cpp

@@ -76,7 +76,52 @@ class FunctionArrayEnumerate : public IFunction
 
 REGISTER_FUNCTION(ArrayEnumerate)
 {
-    factory.registerFunction<FunctionArrayEnumerate>();
+    FunctionDocumentation::Description description = R"(
+Returns the array `[1, 2, 3, ..., length (arr)]`
+
+This function is normally used with the [`ARRAY JOIN`](/sql-reference/statements/select/array-join) clause. It allows counting something just
+once for each array after applying `ARRAY JOIN`.
+This function can also be used in higher-order functions. For example, you can use it to get array indexes for elements that match a condition.
+)";
+    FunctionDocumentation::Syntax syntax = "arrayEnumerate(x)";
+    FunctionDocumentation::Arguments arguments = {
+        {"x", "The array to enumerate. [`Array`](/sql-reference/data-types/array)."}
+    };
+    FunctionDocumentation::ReturnedValue returned_value = "Returns the array `[1, 2, 3, ..., length (arr)]`. Array(UInt32)"
+    FunctionDocumentation::Examples examples = {{"Basic example with ARRAY JOIN", R"(
+CREATE TABLE test
+(
+    `id` UInt8,
+    `tag` Array(String),
+    `version` Array(String)
+)
+ENGINE = MergeTree
+ORDER BY id;
+
+INSERT INTO test VALUES (1, ['release-stable', 'dev', 'security'], ['2.4.0', '2.6.0-alpha', '2.4.0-sec1']);
+
+SELECT
+    id,
+    tag,
+    version,
+    seq
+FROM test
+ARRAY JOIN
+    tag,
+    version,
+    arrayEnumerate(tag) AS seq
+    )", R"(
+┌─id─┬─tag────────────┬─version─────┬─seq─┐
+│  1 │ release-stable │ 2.4.0       │   1 │
+│  1 │ dev            │ 2.6.0-alpha │   2 │
+│  1 │ security       │ 2.4.0-sec1  │   3 │
+└────┴────────────────┴─────────────┴─────┘
+    )"}};
+    FunctionDocumentation::IntroducedIn introduced_in = {1, 1};
+    FunctionDocumentation::Category category = FunctionDocumentation::Category::Array;
+    FunctionDocumentation documentation = {description, syntax, arguments, returned_value, examples, introduced_in, category};
+
+    factory.registerFunction<FunctionArrayEnumerate>(documentation);
 }
 
 }

src/Functions/array/arrayEnumerateUniqRanked.cpp

@@ -16,7 +16,57 @@ class FunctionArrayEnumerateUniqRanked : public FunctionArrayEnumerateRankedExte
 
 REGISTER_FUNCTION(ArrayEnumerateUniqRanked)
 {
-    factory.registerFunction<FunctionArrayEnumerateUniqRanked>();
+    FunctionDocumentation::Description description = R"(
+Returns an array (or multi-dimensional array) with the same dimensions as the source array,
+indicating for each element what it's position is among elements with the same value.
+It allows for enumeration of a multi-dimensional array with the ability to specify how deep to look inside the array.
+)";
+    FunctionDocumentation::Syntax syntax = "arrayEnumerateUniqRanked(clear_depth, arr, max_array_depth)";
+    FunctionDocumentation::Arguments arguments = {
+        {"clear_depth", "Enumerate elements at the specified level separately. Positive [Integer](../data-types/int-uint.md) less than or equal to `max_arr_depth`."},
+        {"arr", "N-dimensional array to enumerate. [Array](/sql-reference/data-types/array)."},
+        {"max_array_depth", "The maximum effective depth. Positive [Integer](../data-types/int-uint.md) less than or equal to the depth of `arr`."}
+    };
+    FunctionDocumentation::ReturnedValue returned_value = "Returns an N-dimensional array the same size as `arr` with each element showing the position of that element in relation to other elements of the same value."
+    FunctionDocumentation::Examples examples = {
+        {"Example 1", R"(
+With `clear_depth=1` and `max_array_depth=1`, the result of `arrayEnumerateUniqRanked` is identical to that which [`arrayEnumerateUniq`](#arrayenumerateuniq) would give for the same array.
+
+```sql
+SELECT arrayEnumerateUniqRanked(1, [1,2,1], 1);
+```
+        )", "[1,1,2]"},
+        {"Example 2", R"(
+
+With `clear_depth=1` and `max_array_depth=1`, the result of `arrayEnumerateUniqRanked` is identical to that which [`arrayEnumerateUniq`](#arrayenumerateuniq) would give for the same array.
+
+```sql
+SELECT arrayEnumerateUniqRanked(1, [[1,2,3],[2,2,1],[3]], 2);", "[[1,1,1],[2,3,2],[2]]
+```
+)", "[1,1,2]"},
+        {"Example 3", R"(
+
+In this example, `arrayEnumerateUniqRanked` is used to obtain an array indicating, for each element of the multidimensional array, what its position is among elements of the same value. For the first row of the passed array,`[1,2,3]`, the corresponding result is `[1,1,1]`, indicating that this is the first time `1`,`2` and `3` are encountered. For the second row of the provided array,`[2,2,1]`, the corresponding result is `[2,3,3]`, indicating that `2` is encountered for a second and third time, and `1` is encountered for the second time. Likewise, for the third row of the provided array `[3]` the corresponding result is `[2]` indicating that `3` is encountered for the second time.
+
+```sql
+SELECT arrayEnumerateUniqRanked(1, [[1,2,3],[2,2,1],[3]], 2);
+```
+        )", "[[1,1,1],[2,3,2],[2]]"
+    },
+    {"Example 4", R"(
+
+Changing `clear_depth=2`, results in elements being enumerated separately for each row.
+
+```sql
+SELECT arrayEnumerateUniqRanked(2, [[1,2,3],[2,2,1],[3]], 2);
+```
+        )", "[[1,1,1],[1,2,1],[1]]"},
+};
+    FunctionDocumentation::IntroducedIn introduced_in = {1, 1};
+    FunctionDocumentation::Category category = FunctionDocumentation::Category::Array;
+    FunctionDocumentation documentation = {description, syntax, arguments, returned_value, examples, introduced_in, category};
+
+    factory.registerFunction<FunctionArrayEnumerateUniqRanked>(documentation);
 }
 
 }

tests/queries/0_stateless/02415_all_new_functions_must_be_documented.reference

@@ -98,11 +98,9 @@ arrayCumSum
 arrayCumSumNonNegative
 arrayDifference
 arrayDistinct
-arrayEnumerate
 arrayEnumerateDense
 arrayEnumerateDenseRanked
 arrayEnumerateUniq
-arrayEnumerateUniqRanked
 arrayExists
 arrayFill
 arrayFilter