refactor(ecs): add struct for querying using component metadata

1 files changed, 21 insertions, 5 deletions

diff --git a/ecs/src/lib.rs b/ecs/src/lib.rs
index d217525..1b9a31b 100644
--- a/ecs/src/lib.rs
+++ b/ecs/src/lib.rs
@@ -23,6 +23,7 @@ use crate::event::component::Kind as ComponentEventKind;
 use crate::extension::{Collector as ExtensionCollector, Extension};
 use crate::lock::{Lock, WriteGuard};
 use crate::phase::{Phase, START as START_PHASE};
+use crate::query::flexible::Query as FlexibleQuery;
 use crate::query::options::{Not, Options as QueryOptions, With};
 use crate::relationship::{ChildOf, DependsOn, Relationship};
 use crate::sole::Sole;
@@ -30,6 +31,7 @@ use crate::stats::Stats;
 use crate::system::{System, SystemComponent};
 use crate::type_name::TypeName;
 use crate::uid::{Kind as UidKind, Uid};
+use crate::util::Sortable;
 
 pub mod actions;
 pub mod component;
@@ -182,6 +184,16 @@ impl World
         Query::new(self)
     }
 
+    pub fn flexible_query<CompMetadata>(
+        &self,
+        comp_metadata: CompMetadata,
+    ) -> FlexibleQuery<CompMetadata>
+    where
+        CompMetadata: Sortable<Item = ComponentMetadata> + AsRef<[ComponentMetadata]>,
+    {
+        FlexibleQuery::new(self, comp_metadata)
+    }
+
     /// Performs a single tick.
     ///
     /// # Panics
@@ -440,14 +452,18 @@ impl World
 
     fn emit_event_by_id(&self, event_id: Uid)
     {
-        for (system,) in self
-            .query::<(&SystemComponent,), ()>()
-            .iter_with_extra_comps([ComponentMetadata {
+        let query = self.flexible_query([
+            ComponentMetadata::of::<SystemComponent>(),
+            ComponentMetadata {
                 id: event_id,
                 is_optional: ComponentIsOptional::No,
-            }])
+            },
+        ]);
+
+        for (system,) in query
+            .iter::<()>()
+            .into_component_iter::<(&SystemComponent,)>(self)
         {
-            // SAFETY: The world lives long enough
             unsafe {
                 system.system.run(self);
             }