Add documentation

init

2 files changed, 33 insertions, 0 deletions

diff --git a/ydb/docs/ru/core/yql/reference/yql-core/builtins/_includes/basic/udf.md b/ydb/docs/ru/core/yql/reference/yql-core/builtins/_includes/basic/udf.md
new file mode 100644
index 00000000000..bf90c06cfb6
--- /dev/null
+++ b/ydb/docs/ru/core/yql/reference/yql-core/builtins/_includes/basic/udf.md
@@ -0,0 +1,31 @@
+## Udf {#udf}
+
+Строит `Callable` по заданному названию функции и опциональным `external user types`, `RunConfig` и `TypeConfig`.
+
+* `Udf(Foo::Bar)` — Функция `Foo::Bar` без дополнительных параметров.
+* `Udf(Foo::Bar)(1, 2, 'abc')` — Вызов udf `Foo::Bar`.
+* `Udf(Foo::Bar, Int32, @@{"device":"AHCI"}@@ as TypeConfig")(1, 2, 'abc')` — Вызов udf `Foo::Bar` с дополнительным типом `Int32` и указанным `TypeConfig`.
+* `Udf(Foo::Bar, "1e9+7" as RunConfig")(1, 'extended' As Precision)` — Вызов udf `Foo::Bar` с указанным `RunConfig` и именоваными параметрами.
+
+
+**Сигнатуры**
+```
+Udf(Callable[, T1, T2, ..., T_N][, V1 as TypeConfig][,V2 as RunConfig]])->Callable
+```
+Где `T1`, `T2`, и т. д. -- дополнительные (`external`) пользовательские типы.
+
+**Примеры**
+```
+$IsoParser = Udf(DateTime2::ParseIso8601);
+SELECT $IsoParser("2022-01-01");
+```
+```
+SELECT Udf(Unicode::IsUtf)("2022-01-01")
+```
+```
+$config = @@{
+    "name":"MessageFoo",
+    "meta": "..."
+}@@;
+SELECT Udf(Protobuf::TryParse, $config As TypeConfig)("")
+```
diff --git a/ydb/docs/ru/core/yql/reference/yql-core/builtins/basic.md b/ydb/docs/ru/core/yql/reference/yql-core/builtins/basic.md
index b3c267dbb50..f73a44dfbbe 100644
--- a/ydb/docs/ru/core/yql/reference/yql-core/builtins/basic.md
+++ b/ydb/docs/ru/core/yql/reference/yql-core/builtins/basic.md
@@ -17,6 +17,8 @@
 
 {% include [x](_includes/basic/random.md) %}
 
+{% include [x](_includes/basic/udf.md) %}
+
 {% include [x](_includes/basic/current_utc.md) %}
 
 {% include [x](_includes/basic/current_tz.md) %}