feat: 语法树的访问者和类型检测访问者 (#56)

Reviewed-on: PostGuard/Canon#56

Canon.Tests/Utils/CompilerHelpers.cs

@@ -0,0 +1,18 @@
+using Canon.Core.Abstractions;
+using Canon.Core.GrammarParser;
+using Canon.Core.LexicalParser;
+using Canon.Core.SyntaxNodes;
+
+namespace Canon.Tests.Utils;
+
+public static class CompilerHelpers
+{
+    public static ProgramStruct Analyse(string program)
+    {
+        ILexer lexer = new Lexer();
+        IGrammarParser grammarParser = GeneratedGrammarParser.Instance;
+
+        IEnumerable<SemanticToken> tokens = lexer.Tokenize(new StringSourceReader(program));
+        return grammarParser.Analyse(tokens);
+    }
+}

Canon.Tests/Utils/SampleSyntaxTreeVisitor.cs

@@ -0,0 +1,85 @@
+using System.Text;
+using Canon.Core.Abstractions;
+using Canon.Core.SyntaxNodes;
+
+namespace Canon.Tests.Utils;
+
+public class SampleSyntaxTreeVisitor : SyntaxNodeVisitor
+{
+    private readonly StringBuilder _builder = new();
+
+    public override string ToString()
+    {
+        return _builder.ToString();
+    }
+
+    public override void PreVisit(ProgramStruct programStruct)
+    {
+        _builder.Append(programStruct).Append('\n');
+    }
+
+    public override void PostVisit(ProgramStruct programStruct)
+    {
+        _builder.Append(programStruct).Append('\n');
+    }
+
+    public override void PreVisit(ProgramHead programHead)
+    {
+        _builder.Append(programHead).Append('\n');
+    }
+
+    public override void PostVisit(ProgramHead programHead)
+    {
+        _builder.Append(programHead).Append('\n');
+    }
+
+    public override void PreVisit(ProgramBody programBody)
+    {
+        _builder.Append(programBody).Append('\n');
+    }
+
+    public override void PostVisit(ProgramBody programBody)
+    {
+        _builder.Append(programBody).Append('\n');
+    }
+
+    public override void PreVisit(SubprogramDeclarations subprogramDeclarations)
+    {
+        _builder.Append(subprogramDeclarations).Append('\n');
+    }
+
+    public override void PostVisit(SubprogramDeclarations subprogramDeclarations)
+    {
+        _builder.Append(subprogramDeclarations).Append('\n');
+    }
+
+    public override void PreVisit(CompoundStatement compoundStatement)
+    {
+        _builder.Append(compoundStatement).Append('\n');
+    }
+
+    public override void PostVisit(CompoundStatement compoundStatement)
+    {
+        _builder.Append(compoundStatement).Append('\n');
+    }
+
+    public override void PreVisit(StatementList statementList)
+    {
+        _builder.Append(statementList).Append('\n');
+    }
+
+    public override void PostVisit(StatementList statementList)
+    {
+        _builder.Append(statementList).Append('\n');
+    }
+
+    public override void PreVisit(Statement statement)
+    {
+        _builder.Append(statement).Append('\n');
+    }
+
+    public override void PostVisit(Statement statement)
+    {
+        _builder.Append(statement).Append('\n');
+    }
+}