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/PrimitiveParserTests.cs

@@ -0,0 +1,84 @@
+using CanonSharp.Combinator;
+using CanonSharp.Combinator.Abstractions;
+using CanonSharp.Combinator.Extensions;
+using CanonSharp.Tests.Utils;
+using static CanonSharp.Combinator.ParserBuilder;
+
+namespace CanonSharp.Tests.CombinatorsTests;
+
+public class PrimitiveParserTests : ParserTestsBase
+{
+    [Fact]
+    public void PureTest()
+    {
+        Parser<char, char> parser = Pure<char, char>('a');
+        ValidateSuccessfulResult(parser, 'a', "abc");
+
+        parser = Pure<char, char>(_ => 'a');
+        ValidateSuccessfulResult(parser, 'a', "abc");
+    }
+
+    [Fact]
+    public void NullTest()
+    {
+        Parser<char, Unit> parser = Null<char>();
+        ValidateSuccessfulResult(parser, Unit.Instance, "abc");
+    }
+
+    [Fact]
+    public void FailTest()
+    {
+        Parser<char, char> parser = Fail<char, char>();
+        ValidateFailedResult(parser, "abc");
+
+        parser = Fail<char, char>("Failed message");
+        FailedResult<char, char> result = ValidateFailedResult(parser, "abc");
+        Assert.Equal("Failed message", result.Message);
+
+        parser = Fail<char, char>(x => $"{x}");
+        result = ValidateFailedResult(parser, "abc");
+        Assert.Equal("a<0x61>", result.Message);
+
+        parser = Fail<char, char>(new InvalidOperationException());
+        result = ValidateFailedResult(parser, "abc");
+        Assert.IsType<InvalidOperationException>(result.Exception.InnerException);
+    }
+
+    [Fact]
+    public void SatisfyTest()
+    {
+        Parser<char, char> parser = Satisfy<char>(char.IsLetter);
+        ValidateSuccessfulResult(parser, 'a', "abc");
+        ValidateFailedResult(parser, "123");
+    }
+
+    [Fact]
+    public void AnyTest()
+    {
+        Parser<char, char> parser = Any<char>();
+        ValidateSuccessfulResult(parser, '1', "123");
+    }
+
+    [Fact]
+    public void TokenTest()
+    {
+        Parser<char, char> parser = Token('a');
+        ValidateSuccessfulResult(parser, 'a', "abc");
+    }
+
+    [Fact]
+    public void TakeTest()
+    {
+        Parser<char, IEnumerable<char>> parser = Take<char>(5);
+        ValidateSuccessfulResult(parser, ['h', 'e', 'l', 'l', 'o'], "hello");
+        ValidateFailedResult(parser, "abc");
+    }
+
+    [Fact]
+    public void SkipTest()
+    {
+        Parser<char, char> parser = Skip<char>(5).Bind(_ => Token(','));
+        ValidateSuccessfulResult(parser, ',', "hello,world.");
+        ValidateFailedResult(parser, "abc");
+    }
+}