C# ANTLR 解析器没有实现继承的抽象成员 TokenNames.get

Question

我正在尝试在 Mono 上的 C# 中使用 ANTLR 4.5.3 解析器(从 macOS 10.11.3 上的 Xamarin Studio 6.1.2 运行)，但是 antlr4 生成的代码Java 命令行工具有一个错误导致无法编译。

我的语法如下:

grammar Hello;

HELLO: 'hello';
WORD: [a-z]+;

greeting: HELLO WORD;

WS: [ \n\t\r]+ -> skip;

当语法通过antlr4时没有错误或警告，但在 Xamarin Studio 中编译生成的 HelloParser类失败:

Error CS0534: HelloParser does not implement inherited abstract member Antlr4.Runtime.Recognizer<Antlr4.Runtime.IToken,Antlr4.Runtime.Atn.ParserATNSimulator>.TokenNames.get (CS0534)

我已经拿到了对应的ANTLR 4.5.3 NuGet包，没有其他错误。生成的解析器类的其余部分似乎没问题。 (生成一个 GreetingContext 类和一个 HelloParser.greeting 方法。)

为什么 ANTLR 没有生成这个方法，我该如何修复这个错误？

如果需要，这里是 HelloParser.cs 的全部内容文件:

//------------------------------------------------------------------------------
// <auto-generated>
//     This code was generated by a tool.
//     ANTLR Version: 4.5.3
//
//     Changes to this file may cause incorrect behavior and will be lost if
//     the code is regenerated.
// </auto-generated>
//------------------------------------------------------------------------------

// Generated from Hello.g4 by ANTLR 4.5.3

// Unreachable code detected
#pragma warning disable 0162
// The variable '...' is assigned but its value is never used
#pragma warning disable 0219
// Missing XML comment for publicly visible type or member '...'
#pragma warning disable 1591
// Ambiguous reference in cref attribute
#pragma warning disable 419

using System;
using System.Text;
using System.Diagnostics;
using System.Collections.Generic;
using Antlr4.Runtime;
using Antlr4.Runtime.Atn;
using Antlr4.Runtime.Misc;
using Antlr4.Runtime.Tree;
using DFA = Antlr4.Runtime.Dfa.DFA;

[System.CodeDom.Compiler.GeneratedCode("ANTLR", "4.5.3")]
[System.CLSCompliant(false)]
public partial class HelloParser : Parser {
    public const int
        HELLO=1, WORD=2, WS=3;
    public const int
        RULE_greeting = 0;
    public static readonly string[] ruleNames = {
        "greeting"
    };

    private static readonly string[] _LiteralNames = {
        null, "'hello'"
    };
    private static readonly string[] _SymbolicNames = {
        null, "HELLO", "WORD", "WS"
    };
    public static readonly IVocabulary DefaultVocabulary = new Vocabulary(_LiteralNames, _SymbolicNames);

    [NotNull]
    public override IVocabulary Vocabulary
    {
        get
        {
            return DefaultVocabulary;
        }
    }

    public override string GrammarFileName { get { return "Hello.g4"; } }

    public override string[] RuleNames { get { return ruleNames; } }

    public override string SerializedAtn { get { return _serializedATN; } }

    public HelloParser(ITokenStream input)
        : base(input)
    {
        Interpreter = new ParserATNSimulator(this,_ATN);
    }
    public partial class GreetingContext : ParserRuleContext {
        public ITerminalNode HELLO() { return GetToken(HelloParser.HELLO, 0); }
        public ITerminalNode WORD() { return GetToken(HelloParser.WORD, 0); }
        public GreetingContext(ParserRuleContext parent, int invokingState)
            : base(parent, invokingState)
        {
        }
        public override int RuleIndex { get { return RULE_greeting; } }
        public override void EnterRule(IParseTreeListener listener) {
            IHelloListener typedListener = listener as IHelloListener;
            if (typedListener != null) typedListener.EnterGreeting(this);
        }
        public override void ExitRule(IParseTreeListener listener) {
            IHelloListener typedListener = listener as IHelloListener;
            if (typedListener != null) typedListener.ExitGreeting(this);
        }
    }

    [RuleVersion(0)]
    public GreetingContext greeting() {
        GreetingContext _localctx = new GreetingContext(Context, State);
        EnterRule(_localctx, 0, RULE_greeting);
        try {
            EnterOuterAlt(_localctx, 1);
            {
            State = 2; Match(HELLO);
            State = 3; Match(WORD);
            }
        }
        catch (RecognitionException re) {
            _localctx.exception = re;
            ErrorHandler.ReportError(this, re);
            ErrorHandler.Recover(this, re);
        }
        finally {
            ExitRule();
        }
        return _localctx;
    }

    private static string _serializedATN = _serializeATN();
    private static string _serializeATN()
    {
        StringBuilder sb = new StringBuilder();
        sb.Append("\x3\x430\xD6D1\x8206\xAD2D\x4417\xAEF1\x8D80\xAADD\x3\x5");
        sb.Append("\b\x4\x2\t\x2\x3\x2\x3\x2\x3\x2\x3\x2\x2\x2\x3\x2\x2\x2\x6\x2");
        sb.Append("\x4\x3\x2\x2\x2\x4\x5\a\x3\x2\x2\x5\x6\a\x4\x2\x2\x6\x3\x3\x2");
        sb.Append("\x2\x2\x2");
        return sb.ToString();
    }

    public static readonly ATN _ATN =
        new ATNDeserializer().Deserialize(_serializedATN.ToCharArray());
}

如果您需要任何其他生成的文件，请发表评论，以防您自己的 ANTLR 无法重现该错误。

Answer 1

NuGet 包使用 Sam Harwell's optimized C# target而不是标准的。您不能将一个版本的工具与另一个版本的运行时库一起使用，它们不兼容:查看 release notes here .

因此，如果您想继续使用 NuGet 包以方便使用，您可以使用其中的工具 - 该包只是一个 zip 文件。

我不知道您是否可以使用 Xamarin Studio 简化此工作流，但使用 Visual Studio 您可以完全跳过手动解析器生成步骤，因为该包与 MSBuild 集成以在编译时生成解析器代码。