feat(stdlib): add unflatten vrl function

Cargo.toml

@@ -142,7 +142,7 @@ iana-time-zone = { version = "0.1", optional = true }
 idna = { version = "0.5", optional = true }
 indexmap = { version = "~2.4.0", default-features = false, features = ["std"], optional = true}
 indoc = {version = "2", optional = true }
-itertools = { version = "0.13", default-features = false, optional = true }
+itertools = { version = "0.13", default-features = false, features=["use_std"], optional = true }
 lalrpop-util = { version = "0.20", optional = true }
 mlua = { version = "0.9", default-features = false, features = ["lua54", "send", "vendored"], optional = true}
 nom = { version = "7", default-features = false, features = ["std"], optional = true }

benches/stdlib.rs

@@ -159,6 +159,7 @@ criterion_group!(
               to_syslog_severity,
               to_unix_timestamp,
               truncate,
+              unflatten,
               unique,
               // TODO: Cannot pass a Path to bench_function
               //unnest
@@ -2718,6 +2719,31 @@ bench_function! {
     }
 }
 
+bench_function! {
+    unflatten => vrl::stdlib::Unflatten;
+
+    nested_map {
+        args: func_args![value: value!({"parent.child1": 1, "parent.child2": 2, key: "val"})],
+        want: Ok(value!({parent: {child1: 1, child2: 2}, key: "val"})),
+    }
+
+    map_and_array {
+        args: func_args![value: value!({
+            "parent.child1": [1, [2, 3]],
+            "parent.child2.grandchild1": 1,
+            "parent.child2.grandchild2": [1, [2, 3], 4],
+            "key": "val",
+        })],
+        want: Ok(value!({
+            "parent": {
+                "child1": [1, [2, 3]],
+                "child2": {"grandchild1": 1, "grandchild2": [1, [2, 3], 4]},
+            },
+            "key": "val",
+        })),
+    }
+}
+
 bench_function! {
     unique => vrl::stdlib::Unique;
 

changelog.d/81.feature.md

@@ -0,0 +1 @@
+Added `unflatten` function to inverse the result of the `flatten` function. This function is useful when you want to convert a flattened object back to its original form.

lib/tests/tests/functions/flatten/from_unflatten.vrl

@@ -0,0 +1,4 @@
+# object: { "a.b.c.d": 1, "a.b.c.e": 2, "a.b.f": 3, "a.g": 4 }
+# result: { "a.b.c.d": 1, "a.b.c.e": 2, "a.b.f": 3, "a.g": 4 }
+
+flatten(unflatten(.))

lib/tests/tests/functions/flatten/simple.vrl

@@ -0,0 +1,4 @@
+# object: { "a": { "b": { "c": { "d": 1, "e": 2 }, "f": 3 }, "g": 4 } }
+# result: { "a.b.c.d": 1, "a.b.c.e": 2, "a.b.f": 3, "a.g": 4 }
+
+flatten(.)

lib/tests/tests/functions/unflatten/from_flatten.vrl

@@ -0,0 +1,4 @@
+# object: { "a": { "b": { "c": { "d": 1, "e": 2 }, "f": 3 }, "g": 4 } }
+# result: { "a": { "b": { "c": { "d": 1, "e": 2 }, "f": 3 }, "g": 4 } }
+
+unflatten(flatten(.))

lib/tests/tests/functions/unflatten/simple.vrl

@@ -0,0 +1,4 @@
+# object: { "a.b.c.d": 1, "a.b.c.e": 2, "a.b.f": 3, "a.g": 4 }
+# result: { "a": { "b": { "c": { "d": 1, "e": 2 }, "f": 3 }, "g": 4 } }
+
+unflatten(.)

src/stdlib/mod.rs

@@ -202,6 +202,7 @@ cfg_if::cfg_if! {
         mod to_unix_timestamp;
         mod community_id;
         mod truncate;
+        mod unflatten;
         mod type_def;
         mod unique;
         mod unnest;
@@ -379,6 +380,7 @@ cfg_if::cfg_if! {
         pub use to_unix_timestamp::ToUnixTimestamp;
         pub use truncate::Truncate;
         pub use type_def::TypeDef;
+        pub use unflatten::Unflatten;
         pub use unique::Unique;
         pub use unnest::Unnest;
         pub use upcase::Upcase;
@@ -566,6 +568,7 @@ pub fn all() -> Vec<Box<dyn Function>> {
         Box::new(CommunityID),
         Box::new(Truncate),
         Box::new(TypeDef),
+        Box::new(Unflatten),
         Box::new(Unique),
         Box::new(Unnest),
         Box::new(Upcase),