Simplify text reconstruction

ToyIncrementalParser/Interpreter/Interpreter.cs

@@ -2,7 +2,6 @@
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
-using System.Text;
 using ToyIncrementalParser.Syntax;
 
 namespace ToyIncrementalParser.Interpreter;
@@ -20,7 +19,7 @@ public ToyValue Execute(ProgramSyntax program, TextWriter? output = null)
     {
         ArgumentNullException.ThrowIfNull(program);
 
-        var text = ReconstructText(program);
+        var text = program.FullText;
         return ExecuteInternal(program, text, output ?? TextWriter.Null);
     }
 
@@ -248,32 +247,6 @@ private void DefineFunction(FunctionDefinitionSyntax definition, Environment env
         environment.Define(definition.Identifier.Text, ToyValue.FromFunction(function));
     }
 
-    private static string ReconstructText(SyntaxNode node)
-    {
-        var builder = new StringBuilder();
-        AppendNodeText(node, builder);
-        return builder.ToString();
-    }
-
-    private static void AppendNodeText(SyntaxNode node, StringBuilder builder)
-    {
-        if (node is SyntaxToken token)
-        {
-            foreach (var trivia in token.LeadingTrivia)
-                builder.Append(trivia.Text);
-
-            builder.Append(token.Text);
-
-            foreach (var trivia in token.TrailingTrivia)
-                builder.Append(trivia.Text);
-
-            return;
-        }
-
-        foreach (var child in node.GetChildren())
-            AppendNodeText(child, builder);
-    }
-
     private static double ExpectNumber(ToyValue value, SyntaxToken token, EvaluationContext context)
     {
         if (value.Kind != ToyValueKind.Number)

ToyIncrementalParser/Parser/Blender.cs

@@ -6,7 +6,7 @@
 
 namespace ToyIncrementalParser.Parser;
 
-internal sealed class Blender : ISymbolStream, ICharacterSource
+internal sealed class Blender : ISymbolStream
 {
     private readonly IText _newText;
     private readonly Stack<SymbolEntry> _symbolStack = new();
@@ -183,12 +183,6 @@ internal char ConsumeCharacterCore()
 
     internal int CurrentPositionCore => _currentPosition;
 
-    // ICharacterSource implementation delegates to the wrapper
-    char ICharacterSource.PeekCharacter() => _characterSource.PeekCharacter();
-    char ICharacterSource.ConsumeCharacter() => _characterSource.ConsumeCharacter();
-    void ICharacterSource.PushBack(char ch) => _characterSource.PushBack(ch);
-    int ICharacterSource.CurrentPosition => _characterSource.CurrentPosition;
-
     private void BuildInitialStack(GreenProgramNode oldRoot, IText newText, TextChange change)
     {
         // We build the initial work stack by processing the old program from left to right using a work stack.
@@ -693,7 +687,7 @@ private void CrumbleTopSymbol()
     private SymbolToken LexNextToken()
     {
         // Reuse the lexer if we have one, otherwise create a new one
-        _lexer ??= new Lexer(this);
+        _lexer ??= new Lexer(_characterSource);
         // The lexer will advance _currentPosition as it consumes characters
         // After lexing, _currentPosition will be at lexed.FullEnd
         var lexed = _lexer.NextToken();