feat: Adding ValueEmitter, LambdaEvaluatorSystem

5 files changed, 134 insertions, 31 deletions

diff --git a/core/src/main/java/coffee/liz/ecs/DAGWorld.java b/core/src/main/java/coffee/liz/ecs/DAGWorld.java
index 24d5adc..5d052ab 100644
--- a/core/src/main/java/coffee/liz/ecs/DAGWorld.java
+++ b/core/src/main/java/coffee/liz/ecs/DAGWorld.java
@@ -2,6 +2,7 @@ package coffee.liz.ecs;
 
 import coffee.liz.ecs.model.Component;
 import coffee.liz.ecs.model.Entity;
+import coffee.liz.ecs.model.Query;
 import coffee.liz.ecs.model.System;
 import coffee.liz.ecs.model.World;
 
@@ -10,10 +11,12 @@ import lombok.extern.log4j.Log4j2;
 
 import java.time.Duration;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
+import java.util.LinkedHashMap;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
@@ -42,9 +45,10 @@ public class DAGWorld<T> implements World<T> {
     /** Ordered list of systems for execution. */
     private final List<System<T>> systemExecutionOrder;
 
-    public DAGWorld(final Map<Class<? extends System<T>>, System<T>> systems) {
-        this.systems = systems;
-        this.systemExecutionOrder = buildExecutionOrder(systems.values().stream().toList());
+    @SafeVarargs
+    public DAGWorld(final System<T>... systems) {
+        this.systems = singletonClazzMap(systems);
+        this.systemExecutionOrder = buildExecutionOrder(Arrays.asList(systems));
         log.debug("Executing in order: {}", systemExecutionOrder);
     }
 
@@ -67,19 +71,13 @@ public class DAGWorld<T> implements World<T> {
     }
 
     @Override
-    public Set<Entity> query(final Collection<Class<? extends Component>> components) {
-        if (components.isEmpty()) {
-            return Set.copyOf(entities);
-        }
-
-        final Class<? extends Component> firstType = components.iterator().next();
-        final Set<Entity> candidates = componentCache.get(firstType);
-        if (candidates == null) {
-            return Collections.emptySet();
-        }
-
-        return candidates.stream().filter(entity -> components.stream().allMatch(entity::has))
-                .collect(Collectors.toSet());
+    public Set<Entity> resolve(final Query query) {
+        final Set<Class<? extends Component>> components = query.queryingComponents();
+        return switch (query.filter()) {
+            case ALL_OF -> resolveAllOf(components);
+            case ANY_OF -> resolveAnyOf(components);
+            case NONE_OF -> resolveNoneOf(components);
+        };
     }
 
     @Override
@@ -103,15 +101,48 @@ public class DAGWorld<T> implements World<T> {
                 componentType -> componentCache.computeIfAbsent(componentType, _ -> new HashSet<>()).add(entity)));
     }
 
+    private Set<Entity> resolveAllOf(final Set<Class<? extends Component>> components) {
+        if (components.isEmpty()) {
+            return Set.copyOf(entities);
+        }
+
+        final Class<? extends Component> firstType = components.iterator().next();
+        final Set<Entity> candidates = componentCache.get(firstType);
+        if (candidates == null) {
+            return Collections.emptySet();
+        }
+
+        return candidates.stream().filter(entity -> components.stream().allMatch(entity::has))
+                .collect(Collectors.toSet());
+    }
+
+    private Set<Entity> resolveAnyOf(final Set<Class<? extends Component>> components) {
+        if (components.isEmpty()) {
+            return Collections.emptySet();
+        }
+
+        return entities.stream().filter(entity -> components.stream().anyMatch(entity::has))
+                .collect(Collectors.toSet());
+    }
+
+    private Set<Entity> resolveNoneOf(final Set<Class<? extends Component>> components) {
+        if (components.isEmpty()) {
+            return Set.copyOf(entities);
+        }
+
+        return entities.stream().filter(entity -> components.stream().noneMatch(entity::has))
+                .collect(Collectors.toSet());
+    }
+
     private List<System<T>> buildExecutionOrder(final Collection<System<T>> systems) {
         if (systems.isEmpty()) {
             return Collections.emptyList();
         }
 
         final Map<Class<?>, System<T>> systemMap = systems.stream()
-                .collect(Collectors.toMap(System::getClass, system -> system));
-        final Map<Class<?>, Integer> inDegree = new HashMap<>();
-        final Map<Class<?>, Set<Class<?>>> adjacencyList = new HashMap<>();
+                .collect(Collectors.toMap(System::getClass, system -> system, (_, b) -> b, LinkedHashMap::new));
+        final Map<Class<?>, Integer> inDegree = new LinkedHashMap<>();
+        final Map<Class<?>, Set<Class<?>>> adjacencyList = new LinkedHashMap<>();
 
         systems.forEach(system -> {
             final Class<?> systemClass = system.getClass();
@@ -155,11 +186,23 @@ public class DAGWorld<T> implements World<T> {
     }
 
     @Override
-    public void close() throws Exception {
+    public void dispose() {
         for (final System<T> system : systemExecutionOrder) {
-            system.close();
+            system.dispose();
         }
         componentCache.clear();
         entities.clear();
     }
+
+    @SuppressWarnings("unchecked")
+    private static <T> Map<Class<? extends T>, T> singletonClazzMap(final T... singletons) {
+        final boolean areSingletons = Arrays.stream(singletons).map(t -> (Class<? extends System<T>>) t.getClass())
+                .distinct().count() == singletons.length;
+        if (!areSingletons) {
+            throw new IllegalArgumentException("Only one instance may be used per clazz");
+        }
+
+        return Arrays.stream(singletons).map(t -> Map.entry((Class<? extends T>) t.getClass(), t))
+                .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue));
+    }
 }
diff --git a/core/src/main/java/coffee/liz/ecs/model/Query.java b/core/src/main/java/coffee/liz/ecs/model/Query.java
new file mode 100644
index 0000000..679ea49
--- /dev/null
+++ b/core/src/main/java/coffee/liz/ecs/model/Query.java
@@ -0,0 +1,30 @@
+package coffee.liz.ecs.model;
+
+import java.util.Arrays;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+public record Query(Set<Class<? extends Component>> queryingComponents, QueryFilter filter) {
+    public Query {
+        queryingComponents = Set.copyOf(queryingComponents);
+    }
+
+    @SafeVarargs
+    public static Query allOf(final Class<? extends Component>... components) {
+        return new Query(Arrays.stream(components).collect(Collectors.toSet()), QueryFilter.ALL_OF);
+    }
+
+    @SafeVarargs
+    public static Query anyOf(final Class<? extends Component>... components) {
+        return new Query(Arrays.stream(components).collect(Collectors.toSet()), QueryFilter.ANY_OF);
+    }
+
+    @SafeVarargs
+    public static Query noneOf(final Class<? extends Component>... components) {
+        return new Query(Arrays.stream(components).collect(Collectors.toSet()), QueryFilter.NONE_OF);
+    }
+
+    public enum QueryFilter {
+        ALL_OF, ANY_OF, NONE_OF
+    }
+}
diff --git a/core/src/main/java/coffee/liz/ecs/model/QueryBuilder.java b/core/src/main/java/coffee/liz/ecs/model/QueryBuilder.java
new file mode 100644
index 0000000..eba5021
--- /dev/null
+++ b/core/src/main/java/coffee/liz/ecs/model/QueryBuilder.java
@@ -0,0 +1,25 @@
+package coffee.liz.ecs.model;
+
+import lombok.RequiredArgsConstructor;
+
+import java.util.Set;
+
+@RequiredArgsConstructor
+public class QueryBuilder<T> {
+    private final World<T> world;
+
+    @SafeVarargs
+    public final Set<Entity> allOf(final Class<? extends Component>... components) {
+        return world.resolve(Query.allOf(components));
+    }
+
+    @SafeVarargs
+    public final Set<Entity> anyOf(final Class<? extends Component>... components) {
+        return world.resolve(Query.anyOf(components));
+    }
+
+    @SafeVarargs
+    public final Set<Entity> noneOf(final Class<? extends Component>... components) {
+        return world.resolve(Query.noneOf(components));
+    }
+}
diff --git a/core/src/main/java/coffee/liz/ecs/model/System.java b/core/src/main/java/coffee/liz/ecs/model/System.java
index c4b0bc0..8138a0b 100644
--- a/core/src/main/java/coffee/liz/ecs/model/System.java
+++ b/core/src/main/java/coffee/liz/ecs/model/System.java
@@ -9,7 +9,7 @@ import java.util.Collection;
  * @param <T>
  *            is the state of the stuff outside the {@link World}.
  */
-public interface System<T> extends AutoCloseable {
+public interface System<T> {
     /**
      * {@link System} clazzes that must run before this system.
      *
@@ -27,7 +27,6 @@ public interface System<T> extends AutoCloseable {
      */
     void update(final World<T> world, final T state, final Duration dt);
 
-    @Override
-    default void close() {
+    default void dispose() {
     }
 }
diff --git a/core/src/main/java/coffee/liz/ecs/model/World.java b/core/src/main/java/coffee/liz/ecs/model/World.java
index c59a0d7..668c3d5 100644
--- a/core/src/main/java/coffee/liz/ecs/model/World.java
+++ b/core/src/main/java/coffee/liz/ecs/model/World.java
@@ -1,16 +1,15 @@
 package coffee.liz.ecs.model;
 
 import java.time.Duration;
-import java.util.Collection;
 import java.util.Set;
 
 /**
- * The state of the world.
+ * The game world.
  *
  * @param <T>
  *            is the state of the stuff outside the world.
  */
-public interface World<T> extends AutoCloseable {
+public interface World<T> {
     /**
      * Create unique {@link Entity} in the {@link World}.
      *
@@ -29,11 +28,15 @@ public interface World<T> extends AutoCloseable {
     /**
      * Get entities with {@link Component}s.
      *
-     * @param components
-     *            to query for.
-     * @return All entities with all {@param components}.
+     * @param query
+     *            to query.
+     * @return All entities satisfying {@param query}.
      */
-    Set<Entity> query(final Collection<Class<? extends Component>> components);
+    Set<Entity> resolve(final Query query);
+
+    default QueryBuilder<T> queryable() {
+        return new QueryBuilder<>(this);
+    }
 
     /**
      * Integrate the {@link World}.
@@ -55,4 +58,7 @@ public interface World<T> extends AutoCloseable {
      * @return {@link System} instance of {@param system}.
      */
     <S extends System<T>> S getSystem(final Class<S> system);
+
+    default void dispose() {
+    }
 }