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.Tests/CombinatorsTests/LinqTests.cs

@@ -0,0 +1,29 @@
+using CanonSharp.Combinator.Abstractions;
+using CanonSharp.Combinator.Extensions;
+using static CanonSharp.Combinator.Text.TextParserBuilder;
+using CanonSharp.Tests.Utils;
+
+namespace CanonSharp.Tests.CombinatorsTests;
+
+public class LinqTests : ParserTestsBase
+{
+    [Fact]
+    public void SelectTest1()
+    {
+        Parser<char, string> parser = from token in Char('a')
+            select token.ToString();
+        ValidateSuccessfulResult(parser, "a", "a");
+        ValidateFailedResult(parser, "b");
+    }
+
+    [Fact]
+    public void SelectManyTest1()
+    {
+        Parser<char, int> parser = from _1 in Char('a')
+            from _2 in Char('b')
+            from _3 in Char('c')
+            select 123;
+        ValidateSuccessfulResult(parser, 123, "abc");
+        ValidateFailedResult(parser, "asd");
+    }
+}