Defer GetMethod in ExpandActions

Author: eelstork

Runtime/Details/Node.cs

@@ -3,29 +3,41 @@
 namespace Activ.GOAP{
 public class Node<T> : Base{
 
-    public readonly Node<T> prev;
-    public readonly object  action;
-    public readonly T       state;
-    public float            value;
+    public readonly Node<T>    prev;
+    public readonly Func<Cost> source;
+    public readonly T          state;
+    public float value;
     public float cost{ get; private set; }
+    readonly object  effect;
 
-    public Node(object action, T result, Node<T> prev = null,
+    public Node(Func<Cost> planningAction, T result,
+                Node<T> prev = null, float   cost = 0f){
+        this.source = Assert(planningAction, "Action");;
+        this.state  = Assert(result, "Result");
+        this.prev   = prev;
+        this.cost   = cost + (prev?.cost ?? 0f);
+    }
+
+    // TODO - object should be System.Action and separate
+    // constructor for init state if wanted
+    public Node(object effect, T result, Node<T> prev = null,
                                          float   cost = 0f){
-        this.action = Assert(action, "action");
-        this.state  = Assert(result, "result");
+        this.effect = Assert(effect, "Action");
+        this.state  = Assert(result, "Result");
         this.prev   = prev;
         this.cost   = cost + (prev?.cost ?? 0f);
     }
 
+    public object action => effect ?? source.Method.Name;
+
     public static implicit operator string(Node<T> x)
     => (string)(x.Head());
 
     public static implicit operator Delegate(Node<T> x)
     => (Delegate)(x.Head());
 
-    // Regress to the next action; root (init state) does not count.
-    public object Head()
-    => prev?.prev == null ? action : prev.Head();
+    // Regress to first applicable action; root (init state) excl.
+    public object Head() => prev?.prev==null ? action : prev.Head();
 
     public Node<T>[] Path(int n = 1){
         Node<T>[] @out;
@@ -46,7 +58,7 @@ public string PathToString(){
     }
 
     override public string ToString()
-    => $"[{value:0.0} :: {action} => {state}]"
+    => $"[{value:0.0} :: {effect} => {state}]"
                                 .Replace("System.Object", "object");
 
 }}

Runtime/Solver.cs

@@ -60,7 +60,8 @@ public Node<T> Iterate(int iter=-1){
 
     void ExpandActions(Node<T> x, NodeSet<T> @out){
         if(!(x.state is Agent p)) return;
-        var count = p.Actions()?.Length ?? 0;
+        var actions = p.Actions();
+        var count = actions?.Length ?? 0;
         if(count == 0) return;
         dish.Init(x.state);
         T y = null;
@@ -70,11 +71,9 @@ void ExpandActions(Node<T> x, NodeSet<T> @out){
             var r = q.Actions()[i]();
             if(r.done){
                 dish.Invalidate();
-                if(!brfs && (r.cost <= 0))
-                    throw new Ex(ZERO_COST_ERR);
-                var name = p.Actions()[i].Method.Name;
-                if(@out.Insert(new Node<T>(name, y, x, r.cost)))
-                    dish.Consume();
+                if(!brfs && (r.cost<=0)) throw new Ex(ZERO_COST_ERR);
+                if(@out.Insert(new Node<T>(
+                        actions[i], y, x, r.cost))) dish.Consume();
             }
         }
     }

Tests/Editor/NodeTest.cs

@@ -56,10 +56,12 @@ [Test] public void Path1(){
 
     [Test] public void Head2(){
         var x = new Node<object>(INITIAL_STATE, new object());
-        var y = new Node<object>(ACTION_1, new object(), x);
-        o( y.Head(), ACTION_1);
+        var y = new Node<object>(Costly, new object(), x);
+        o( y.Head(), "Costly");
     }
 
+    Cost Costly() => true;
+
     [Test] public void Path2(){
         var x = new Node<object>(INITIAL_STATE, new object());
         var y = new Node<object>(ACTION_1, new object(), x);