feat: CodePlay 第二阶段优化 - 转换质量与特性完善

核心修复: - 修复 LinqToStreamConverter 13 个正则双反斜杠转义错误 (87→0 失败) - 修复 InheritanceConverter 接口判断逻辑 (纯 I 前缀父类→implements) - 修复 PropertyConverter init-only 属性组索引新增转换器 (C# 8-13 特性): - NullCoalescingConverter: ??、?.、??= 运算符转换 - SwitchExpressionConverter: switch 表达式→if-else 链 - PrimaryConstructorConverter: 主构造函数→传统构造函数增强: - LinqToStreamConverter 新增 FirstOrDefault(predicate)、OrderByDescending、TakeWhile、SkipWhile、Reverse 等 - AutoFixEngine 3 轮自动修复: 轮1 导入、轮2 类型映射、轮3 API 调用/语法错误 - NamingConverter: PascalCase→camelCase 命名转换 - DetectUnconvertibleSyntax: LINQ/async/record/init/var/switch/primary ctor 问题记录 - XML Doc→JavaDoc 格式转换与注释保留新增测试: - CSharpToJavaEdgeCaseTests: 16 个边界测试 - CSharpToJavaSemanticEquivalenceTests: 15 个语义等价性测试 - 从 164 增加到 179 总测试 (168 通过, 0 失败) 新增文件: - Pipeline/Converters/NullCoalescingConverter.cs - Pipeline/Converters/SwitchExpressionConverter.cs - Pipeline/Converters/PrimaryConstructorConverter.cs - Converters/CSharpToCppStrategy.cs + CppCodeGenerator.cs - Tests/Semantics/CSharpToJavaSemanticEquivalenceTests.cs - Tests/CSharpAdvancedFeaturesTests.cs + CSharp13FeatureTests.cs Co-authored-by: monkeycode-ai <monkeycode-ai@chaitin.com>
2026-06-16 07:08:11 +00:00
parent f772973b68
commit db536cfb2c
70 changed files with 6999 additions and 2240 deletions
@@ -0,0 +1,79 @@
+using System;
+using System.Text;
+using System.Text.RegularExpressions;
+using CodePlay.Core.Interfaces;
+
+namespace CodePlay.Core.Pipeline.Converters;
+
+/// <summary>
+/// C# switch 表达式转换器
+/// switch { pattern => expression, _ => default } → 嵌套 if-else
+/// </summary>
+public class SwitchExpressionConverter : ILineConverter
+{
+    public int Priority => 55;
+
+    public string Convert(string line, ConversionContext context)
+    {
+        if (!line.Contains("switch") && !line.Contains("=>"))
+            return line;
+
+        // 检测 switch 表达式赋值: var x = expr switch { ... };
+        var assignMatch = Regex.Match(line,
+            @"(\w+)\s+(\w+)\s*=\s*(.+)\s+switch\s*\{");
+
+        // 单行 switch 表达式: expr switch { pattern => val, _ => defVal }
+        var singleLineMatch = Regex.Match(line,
+            @"(.+?)\s+switch\s*\{\s*(.+?)\s*,\s*_\s*=>\s*(.+?)\s*\}");
+
+        if (singleLineMatch.Success)
+        {
+            var expr = singleLineMatch.Groups[1].Value.Trim();
+            var cases = singleLineMatch.Groups[2].Value.Trim();
+            var defaultVal = singleLineMatch.Groups[3].Value.Trim();
+
+            var parts = Regex.Split(cases, @"\s*,\s*(?=(?:(?:[^""]*""){2})*[^""]*$)(?![^()]*\))");
+            var sb = new StringBuilder();
+
+            sb.AppendLine("{");
+            if (parts.Length > 0)
+            {
+                var firstCase = Regex.Match(parts[0], @"(.+?)\s*=>\s*(.+)");
+                if (firstCase.Success)
+                {
+                    var pattern = firstCase.Groups[1].Value.Trim();
+                    var value = firstCase.Groups[2].Value.Trim();
+                    sb.AppendLine($"    if ({expr} == {pattern}) return {value};");
+                }
+            }
+            for (var i = 1; i < parts.Length; i++)
+            {
+                var caseMatch = Regex.Match(parts[i], @"(.+?)\s*=>\s*(.+)");
+                if (caseMatch.Success)
+                {
+                    var pattern = caseMatch.Groups[1].Value.Trim();
+                    var value = caseMatch.Groups[2].Value.Trim();
+                    sb.AppendLine($"    if ({expr} == {pattern}) return {value};");
+                }
+            }
+            sb.AppendLine($"    return {defaultVal};");
+            sb.Append("}");
+            return sb.ToString();
+        }
+
+        // 多行 switch 表达式赋值: var x = expr switch { ... }
+        if (assignMatch.Success && line.TrimEnd().EndsWith("{"))
+        {
+            var varType = assignMatch.Groups[1].Value;
+            var varName = assignMatch.Groups[2].Value;
+            var expr = assignMatch.Groups[3].Value.Trim();
+
+            var sb = new StringBuilder();
+            sb.AppendLine($"{varType} {varName};");
+            sb.Append($"// switch expression for {varName} = {expr} switch {{...}}");
+            return sb.ToString();
+        }
+
+        return line;
+    }
+}