Create a System Builder Syntax instead of using System Descriptors

crates/bevy_ecs/src/schedule/stage.rs

@@ -49,7 +49,7 @@ impl_downcast!(Stage);
 pub struct ReportExecutionOrderAmbiguities;
 
 /// Stores and executes systems. Execution order is not defined unless explicitly specified;
-/// see `SystemDescriptor` documentation.
+/// see `SystemConfig` documentation.
 pub struct SystemStage {
     /// The WorldId this stage was last run on.
     world_id: Option<WorldId>,

crates/bevy_ecs/src/system/config/system_config.rs

@@ -1,5 +1,6 @@
 use crate::{schedule::*, system::InsertionPoint};
 
+/// Each system has one of these. It is updated using the various traits seen in this [directory](super).
 #[derive(Default)]
 pub struct SystemConfig {
     pub labels: Vec<BoxedSystemLabel>,
@@ -13,28 +14,28 @@ pub struct SystemConfig {
 }
 
 impl SystemConfig {
-    pub fn add_label(&mut self, label: impl SystemLabel) {
+    pub(crate) fn add_label(&mut self, label: impl SystemLabel) {
         self.labels.push(Box::new(label));
     }
-    pub fn add_before(&mut self, label: impl SystemLabel) {
+    pub(crate) fn add_before(&mut self, label: impl SystemLabel) {
         self.before.push(Box::new(label));
     }
-    pub fn add_after(&mut self, label: impl SystemLabel) {
+    pub(crate) fn add_after(&mut self, label: impl SystemLabel) {
         self.after.push(Box::new(label));
     }
-    pub fn set_stage(&mut self, label: impl StageLabel) {
+    pub(crate) fn set_stage(&mut self, label: impl StageLabel) {
         self.stage = Some(Box::new(label));
     }
-    pub fn add_ambiguity_set(&mut self, set: impl AmbiguitySetLabel) {
+    pub(crate) fn add_ambiguity_set(&mut self, set: impl AmbiguitySetLabel) {
         self.ambiguity_sets.push(Box::new(set));
     }
-    pub fn set_run_criteria(&mut self, criteria: RunCriteriaDescriptorOrLabel) {
+    pub(crate) fn set_run_criteria(&mut self, criteria: RunCriteriaDescriptorOrLabel) {
         self.run_criteria = Some(criteria);
     }
-    pub fn startup(&mut self) {
+    pub(crate) fn startup(&mut self) {
         self.startup = true;
     }
-    pub fn set_insertion_point(&mut self, insertion_point: InsertionPoint) {
+    pub(crate) fn set_insertion_point(&mut self, insertion_point: InsertionPoint) {
         self.insertion_point = insertion_point;
     }
 }

crates/bevy_ecs/src/system/system.rs

@@ -31,7 +31,7 @@ impl SystemId {
 ///
 /// Systems are executed in parallel, in opportunistic order; data access is managed automatically.
 /// It's possible to specify explicit execution order between specific systems,
-/// see [SystemDescriptor](crate::schedule::SystemDescriptor).
+/// see [SystemConfig](super::SystemConfig) and the other files in the [./config](super::config) directory.
 pub trait System: Send + Sync + 'static {
     /// The system's input. See [`In`](crate::system::In) for
     /// [`FunctionSystem`](crate::system::FunctionSystem)s.