import ast sys for regex runtime build

StgSharp.RegularAnalysis/RegularMachine/Node.Sequence.cs

@@ -1,12 +1,13 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Reflection.Emit;
 using System.Text;
 using System.Threading.Tasks;
 
 namespace StgSharp.RegularAnalysis
 {
-    internal class RegularSequenceNode : RegularStateNode
+    internal sealed class RegularSequenceNode : RegularStateNode
     {
 
         private string _sequence;
@@ -17,20 +18,9 @@ namespace StgSharp.RegularAnalysis
                              RegularStateNode former,
                              RegularContext context
         )
-        {
-            return true;
-        }
-
-        public override bool TryTransaction(
-                             ReadOnlySpan<RegularStateNode> nodeSpan,
-                             RegularContext context,
-                             out int label
-        )
         {
             int pos = context.Position + 1;
-            if (true) { }
-            label = -1;
-            return false;
+            return context.CurrentCharSpan[pos.._sequence.Length].SequenceEqual(_sequence);
         }
 
     }