Return slice in LookAheadMethods::children() instead of Vec (#1200)

Author: soerenmeier

juniper/CHANGELOG.md

@@ -52,6 +52,7 @@ All user visible changes to `juniper` crate will be documented in this file. Thi
     - Removed `scalar-naivetime` [Cargo feature].
 - Removed lifetime parameter from `ParseError`, `GraphlQLError`, `GraphQLBatchRequest` and `GraphQLRequest`. ([#1081], [#528])
 - Upgraded [GraphiQL] to 3.0.8 version (requires new [`graphql-transport-ws` GraphQL over WebSocket Protocol] integration on server, see `juniper_warp/examples/subscription.rs`). ([#1188], [#1193], [#1203])
+- Made `LookAheadMethods::children()` method to return slice instead of `Vec`. ([#1200])
 
 ### Added
 
@@ -128,6 +129,7 @@ All user visible changes to `juniper` crate will be documented in this file. Thi
 [#1190]: /../../pull/1190
 [#1193]: /../../pull/1193
 [#1199]: /../../pull/1199
+[#1200]: /../../pull/1200
 [#1203]: /../../pull/1203
 [ba1ed85b]: /../../commit/ba1ed85b3c3dd77fbae7baf6bc4e693321a94083
 [CVE-2022-31173]: /../../security/advisories/GHSA-4rx6-g5vg-5f3j

juniper/src/executor/look_ahead.rs

@@ -372,7 +372,9 @@ pub trait LookAheadMethods<'sel, S> {
     fn child_names(&self) -> Vec<&'sel str>;
 
     /// Returns an [`Iterator`] over the children from the current selection.
-    fn children(&self) -> Vec<&Self>;
+    fn children(&self) -> &[Self]
+    where
+        Self: Sized;
 
     /// Returns the parent type, in case there is any for the current selection.
     fn applies_for(&self) -> Option<&str>;
@@ -411,8 +413,8 @@ impl<'a, S> LookAheadMethods<'a, S> for ConcreteLookAheadSelection<'a, S> {
         !self.children.is_empty()
     }
 
-    fn children(&self) -> Vec<&Self> {
-        self.children.iter().collect()
+    fn children(&self) -> &[Self] {
+        &self.children
     }
 
     fn applies_for(&self) -> Option<&str> {
@@ -456,8 +458,8 @@ impl<'a, S> LookAheadMethods<'a, S> for LookAheadSelection<'a, S> {
         !self.children.is_empty()
     }
 
-    fn children(&self) -> Vec<&Self> {
-        self.children.iter().collect()
+    fn children(&self) -> &[Self] {
+        &self.children
     }
 
     fn applies_for(&self) -> Option<&str> {