feat: Parser Combinator库和词法分析器 (#2)

Reviewed-on: https://git.bupt-hpc.cn/jackfiled/CanonSharp/pulls/2
Co-authored-by: jackfiled <xcrenchangjun@outlook.com>
Co-committed-by: jackfiled <xcrenchangjun@outlook.com>

CanonSharp.Combinator/Parsers/Modifiers/DoParser.cs

@@ -0,0 +1,30 @@
+using CanonSharp.Combinator.Abstractions;
+
+namespace CanonSharp.Combinator.Parsers.Modifiers;
+
+/// <summary>
+/// 对结果运行指定操作，但是不做修改操作的解析器
+/// </summary>
+/// <param name="parser">上游解析器</param>
+/// <param name="succeed">对成功结果的操作</param>
+/// <param name="fail">对失败结果的操作</param>
+/// <typeparam name="TToken">输入流类型</typeparam>
+/// <typeparam name="T">解析结果类型</typeparam>
+internal sealed class DoParser<TToken, T>(
+    Parser<TToken, T> parser,
+    Action<T> succeed,
+    Action<FailedResult<TToken, T>> fail) : ModifiedParser<TToken, T, T>(parser)
+{
+    protected override ParseResult<TToken, T> Succeed<TState>(TState state,
+        SuccessfulResult<TToken, T> successfulResult)
+    {
+        succeed(successfulResult.Value);
+        return successfulResult;
+    }
+
+    protected override ParseResult<TToken, T> Fail<TState>(TState state, FailedResult<TToken, T> failedResult)
+    {
+        fail(failedResult);
+        return failedResult;
+    }
+}