Implement optimization for collapse instruction.

Assets/Cryville/Common/Pdt/PdtEvaluatorBase.cs

@@ -41,8 +41,10 @@ namespace Cryville.Common.Pdt {
 		public void Optimize(PdtExpression exp) {
 			_framecount = 0;
 			_goffset = 0;
+			List<PdtInstruction.Collapse> ct;
+			var cols = new Dictionary<LinkedListNode<PdtInstruction>, List<PdtInstruction.Collapse>>();
 			var il = exp.Instructions;
-			for (_rip = il.First; _rip != null; _rip = _rip.Next) {
+			for (_rip = il.First; _rip != null; _rip = _rip == null ? il.First : _rip.Next) {
 				var i = _rip.Value;
 				if (i is PdtInstruction.Operate) {
 					int fc0 = _framecount;
@@ -63,6 +65,33 @@ namespace Cryville.Common.Pdt {
 						for (var j = 0; j <= fc1; j++) il.Remove(_rip.Previous);
 					}
 				}
+				else if (i is PdtInstruction.Collapse) {
+					var t = (PdtInstruction.Collapse)i;
+					try {
+						var pins = _rip;
+						i.Execute(this);
+						if (_rip == pins) {
+							_rip = _rip.Next;
+							il.Remove(_rip.Previous);
+							il.Remove(_rip.Previous);
+							_rip = _rip.Previous;
+						}
+						else {
+							_rip = pins.Previous;
+							while (_rip.Next != t.Target) il.Remove(_rip.Next);
+							il.Remove(_rip.Next);
+							if (cols.TryGetValue(t.Target, out ct)) {
+								foreach (var u in ct) u.Target = _rip;
+								cols.Remove(t.Target);
+								cols.Add(_rip, ct);
+							}
+						}
+					}
+					catch (Exception) {
+						if (cols.TryGetValue(t.Target, out ct)) ct.Add(t);
+						else cols.Add(t.Target, new List<PdtInstruction.Collapse> { t });
+					}
+				}
 				else if (i is PdtInstruction.PushVariable) {
 					i.Execute(this);
 					var frame = _stack[_framecount - 1];
@@ -72,6 +101,15 @@ namespace Cryville.Common.Pdt {
 					}
 				}
 				else i.Execute(this);
+				if (_rip != null && cols.TryGetValue(_rip, out ct)) {
+					unsafe {
+						fixed (StackFrame* frame = &_stack[_framecount - 1]) {
+							frame->Type = PdtInternalType.Error;
+							frame->Offset = -1;
+							frame->Length = 0;
+						}
+					}
+				}
 			}
 			exp.IsConstant = true;
 			exp.IsPotentialConstant = true;
@@ -118,7 +156,10 @@ namespace Cryville.Common.Pdt {
 		/// <param name="value">The value of the variable.</param>
 		protected abstract void GetVariable(string name, out int type, out byte[] value);
 		internal void Operate(ref string name, int pc) {
-			Operate(GetOperator(name, pc), pc);
+			PdtOperator op;
+			try { op = GetOperator(name, pc); }
+			catch (Exception) { _framecount -= pc; return; }
+			Operate(op, pc);
 		}
 		/// <summary>
 		/// Gets an operator of the specified name and the suggested parameter count.

Assets/Cryville/Common/Pdt/PdtExpression.cs

@@ -80,7 +80,7 @@ namespace Cryville.Common.Pdt {
 		public class Collapse : PdtInstruction {
 			private string m_name;
 			public string Name { get { return m_name; } }
-			public LinkedListNode<PdtInstruction> Target { get; private set; }
+			public LinkedListNode<PdtInstruction> Target { get; internal set; }
 			public Collapse(string name, LinkedListNode<PdtInstruction> target) {
 				m_name = name;
 				Target = target;
@@ -195,6 +195,9 @@ namespace Cryville.Common.Pdt {
 								default: pc++; break;
 							}
 						}
+						else if (OP_TYPE[t2.Value[0]] == 1) {
+							colp = new Dictionary<LinkedListNode<PdtInstruction>, string> { { ins.Last, t2.Value } };
+						}
 						t1 = t2;
 						break;
 					case 0x0400: