Add support for tuple paths

Author: MrGVSV

crates/bevy_reflect/src/path.rs

@@ -15,6 +15,8 @@ pub enum ReflectPathError<'a> {
         index: usize,
         tuple_struct_index: usize,
     },
+    #[error("the current tuple doesn't have a field with the index {tuple_index}")]
+    InvalidTupleIndex { index: usize, tuple_index: usize },
     #[error("the current list doesn't have a value at the index {list_index}")]
     InvalidListIndex { index: usize, list_index: usize },
     #[error("encountered an unexpected token `{token}`")]
@@ -282,6 +284,15 @@ fn read_field<'r, 'p>(
                 },
             )?)
         }
+        ReflectRef::Tuple(reflect_tuple) => {
+            let tuple_index = field.parse::<usize>()?;
+            Ok(reflect_tuple
+                .field(tuple_index)
+                .ok_or(ReflectPathError::InvalidTupleIndex {
+                    index: current_index,
+                    tuple_index,
+                })?)
+        }
         ReflectRef::Enum(reflect_enum) => match reflect_enum.variant_type() {
             VariantType::Struct => {
                 Ok(reflect_enum
@@ -334,6 +345,15 @@ fn read_field_mut<'r, 'p>(
                 },
             )?)
         }
+        ReflectMut::Tuple(reflect_tuple) => {
+            let tuple_index = field.parse::<usize>()?;
+            Ok(reflect_tuple
+                .field_mut(tuple_index)
+                .ok_or(ReflectPathError::InvalidTupleIndex {
+                    index: current_index,
+                    tuple_index,
+                })?)
+        }
         ReflectMut::Enum(reflect_enum) => match reflect_enum.variant_type() {
             VariantType::Struct => {
                 Ok(reflect_enum
@@ -467,6 +487,7 @@ mod tests {
             unit_variant: F,
             tuple_variant: F,
             struct_variant: F,
+            tuple: (bool, f32),
         }
 
         #[derive(Reflect)]
@@ -504,6 +525,7 @@ mod tests {
             unit_variant: F::Unit,
             tuple_variant: F::Tuple(123, 321),
             struct_variant: F::Struct { value: 'm' },
+            tuple: (true, 1.23),
         };
 
         assert_eq!(*a.get_path::<usize>("w").unwrap(), 1);
@@ -516,6 +538,10 @@ mod tests {
         assert_eq!(*a.get_path::<u32>("tuple_variant.1").unwrap(), 321);
         assert_eq!(*a.get_path::<char>("struct_variant.value").unwrap(), 'm');
 
+        assert_eq!(*a.get_path::<bool>("tuple.0").unwrap(), true);
+        *a.get_path_mut::<bool>("tuple.0").unwrap() = false;
+        assert_eq!(*a.get_path::<bool>("tuple.0").unwrap(), false);
+
         *a.get_path_mut::<f32>("y[1].baz").unwrap() = 3.0;
         assert_eq!(a.y[1].baz, 3.0);