optimize token channels management

baseline.dtp.State

@@ -0,0 +1,3 @@
+<wpf:ResourceDictionary xml:space="preserve" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:s="clr-namespace:System;assembly=mscorlib" xmlns:ss="urn:shemas-jetbrains-com:settings-storage-xaml" xmlns:wpf="http://schemas.microsoft.com/winfx/2006/xaml/presentation">
+	<s:String x:Key="/Default/SnapshotState/CallTreeHistoryV3/@EntryValue">[{"CurrentPrefix":{"Path":{"Items":[{"Fuid":5,"IsLogicalRoot":true}]}},"BacktraceSelection":{"Path":[]},"DowntraceSelection":{"Path":[{"Fuid":7,"IsLogicalRoot":true},{"Fuid":2305843009215791107,"MergeType":2},{"Fuid":2305843009218936880},{"Fuid":2305843009218936881},{"Fuid":2305843009218937558},{"Fuid":2305843009218937559},{"Fuid":2305843009218937664},{"Fuid":2305843009218937665},{"Fuid":2305843009218937750},{"Fuid":2305843009218937756}]},"GroupedByThreadBacktraceSelection":{"Path":[]},"GroupedByThreadDowntraceSelection":{"Path":[]}}]</s:String>
+	<s:String x:Key="/Default/SnapshotState/CallTreeVisualState/@EntryValue">{"Root":{"Key":{},"Children":[{"$id":"1","Key":{"Fuid":{"Value":7}},"Value":{},"Children":[{"$id":"2","Key":{"Fuid":{"Value":2305843009215791107},"MergeType":2},"Value":{},"Children":[{"$id":"3","Key":{"Fuid":{"Value":2305843009218936880}},"Value":{"ChangedState":2,"Values":2},"Children":[{"$id":"4","Key":{"Fuid":{"Value":2305843009218936881}},"Value":{},"Children":[{"$id":"5","Key":{"Fuid":{"Value":2305843009218936882}},"Value":{"ChangedState":2,"Values":2}},{"$id":"6","Key":{"Fuid":{"Value":2305843009218937558}},"Value":{"ChangedState":2,"Values":2},"Children":[{"$id":"7","Key":{"Fuid":{"Value":2305843009218937559}},"Value":{},"Children":[{"$id":"8","Key":{"Fuid":{"Value":2305843009218937664}},"Value":{"ChangedState":2,"Values":2}}]}]}]}]}]}]}]}}</s:String></wpf:ResourceDictionary>

src/sly/lexer/LexerResult.cs

@@ -19,6 +19,7 @@ public LexerResult(List<Token<IN>> tokens)
         public void SetTokens(List<Token<IN>> tokens)
         {
             Tokens = new TokenChannels<IN>(tokens);
+            Tokens.PreCompute();
         }
 
         public LexerResult(LexicalError error, List<Token<IN>> tokens)

src/sly/lexer/TokenChannel.cs

@@ -47,8 +47,6 @@ private void SetToken(int i, Token<IN> token)
                 }
             }
             Tokens[i] = token;
-            _notNullTokens = Tokens.Where(x => x != null).ToList();
-            _notNullOrEosTokens = Tokens.Where(x => x != null && !x.IsEOS).ToList();
         }
 
         public Token<IN> this[int key]
@@ -77,5 +75,11 @@ public override string ToString()
             }
             return builder.ToString();
         }
+
+        public void PreCompute()
+        {
+            _notNullTokens = Tokens.Where(x => x != null).ToList();
+            _notNullOrEosTokens = Tokens.Where(x => x != null && !x.IsEOS).ToList();
+        }
     }
 }

src/sly/lexer/TokenChannels.cs

@@ -67,13 +67,17 @@ public void Add(Token<IN> token)
         {
             token.TokenChannels = this;
             TokenChannel<IN> channel = null;
+            var mx = _tokenChannels?.Values != null && _tokenChannels.Values.Any() ?  _tokenChannels.Values.Max(x => x.Count) : 0;
+
             if (!TryGet(token.Channel, out channel))
             {
+
+
                 channel = new TokenChannel<IN>(token.Channel);
                 int shift = 0;
                 if (_tokenChannels.Values.Any())
                 {
-                    shift = _tokenChannels.Values.Max(x => x.Count);
+                    shift = mx;
                 }
                 for (int i = 0; i < shift; i++)
                 {
@@ -82,7 +86,7 @@ public void Add(Token<IN> token)
                 _tokenChannels[token.Channel] = channel;
             }
 
-            int index = _tokenChannels.Values.Max(x => x.Count);
+            int index = mx;
             foreach (var VARIABLE in _tokenChannels.Values)
             {
                 for (int i = channel.Count; i < index; i++)
@@ -116,5 +120,13 @@ public override string ToString()
         {
             return string.Join("\n", _tokenChannels.Values.Select(x => x.ToString()).ToArray());
         }
+
+        public void PreCompute()
+        {
+            foreach (var channel in _tokenChannels)
+            {
+                channel.Value.PreCompute();
+            }
+        }
     }
 }