feat-visualization (#33)

尽管里面有点粪，但还是生成了漂亮的树，就当给树施肥了
剩下一个小问题：未考虑节点的宽度（因为名称不一样长），但目前未发现对图生成的明显影响

Co-authored-by: jackfiled <xcrenchangjun@outlook.com>
Reviewed-on: PostGuard/Canon#33
Co-authored-by: Ichirinko <1621543655@qq.com>
Co-committed-by: Ichirinko <1621543655@qq.com>

Canon.Core/SyntaxNodes/NonTerminatedSyntaxNode.cs

@@ -34,4 +34,9 @@ public abstract class NonTerminatedSyntaxNode : SyntaxNodeBase, IEnumerable<Synt
     }
 
     IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
+
+    public override string ToString()
+    {
+        return Type.ToString();
+    }
 }

Canon.Core/SyntaxNodes/SyntaxNodeBase.cs

@@ -29,6 +29,11 @@ public abstract class SyntaxNodeBase : ICCodeGenerator
 
     }
 
+    public override string ToString()
+    {
+        return IsTerminated.ToString();
+    }
+
     public static SyntaxNodeBase Create(SemanticToken token)
     {
         return new TerminatedSyntaxNode { Token = token };

Canon.Core/SyntaxNodes/TerminatedSyntaxNode.cs

@@ -7,4 +7,9 @@ public class TerminatedSyntaxNode : SyntaxNodeBase
     public override bool IsTerminated => true;
 
     public required SemanticToken Token { get; init; }
+
+    public override string ToString()
+    {
+        return Token.LiteralValue;
+    }
 }