如何实现字典中没有的单词必须显示错误？

Question

这是一个使用自定义正则表达式实现字典的程序，它标记了所有输入的每个字符串。现在我希望与任何正则表达式不匹配的字符串必须显示在 "not in grammar" 行中。我找不到任何类型的解决方案。

static void Main(string[] args)
{
    string StringRegex = "\"(?:[^\"\\]|\\.)*\"";
    string IntegerRegex = @"[0-9]+";
    string CommentRegex = @"//.*|/\*[\s\S]*\*/";
    string KeywordRegex = @"\b(?:astart|ainput|atake|aloop|batcommand|batshow|batprint|batmult|batadd|batsub|batdiv|batif|batelse|batgo|batend|till|and)\b";
    string DataTypeRegex = @"\b(?:int|string)\b";
    string IdentifierRegex = @"[a-zA-Z]";
    string ParenthesisRegex = @"\(|\)";
    string BracesRegex = @"\{|\}";
    string ArrayBracketRegex = @"\[|\]";
    string PuncuationRegex = @"\;|\:|\,|\.";
    string RelationalExpressionRegex = @"\>|\<|\==";
    string ArthimeticOperatorRegex = @"\+|\-|\*|\/";
    string WhitespaceRegex = @" ";
    Dictionary<string, string> Regexes = new Dictionary<string, string>()
    {
        {"String", StringRegex},
        {"Integer", IntegerRegex },
        {"Comment", CommentRegex},
        {"Keyword", KeywordRegex},
        {"Datatype", DataTypeRegex },
        {"Identifier", IdentifierRegex },
        {"Parenthesis", ParenthesisRegex  },
        {"Brace", BracesRegex },
        {"Square Bracket", ArrayBracketRegex },
        {"Puncuation Mark", PuncuationRegex },
        {"Relational Expression", RelationalExpressionRegex },
        {"Arithmetic Operator", ArthimeticOperatorRegex },
        {"Whitespace", WhitespaceRegex }
    };

    string input;
    input = Convert.ToString(Console.ReadLine());

    var matches = Regexes.SelectMany(a => Regex.Matches(input, a.Value)
    .Cast<Match>()
    .Select(b =>
            new
            {    
                Value = b.Value + "\n",
                Index = b.Index,
                Token= a.Key 
            }))
    .OrderBy(a => a.Index).ToList();
    for (int i = 0; i < matches.Count; i++)
    {
        if (i + 1 < matches.Count)
        {
            int firstEndPos = (matches[i].Index + matches[i].Value.Length);
            if (firstEndPos > matches[(i + 1)].Index)
            {
                matches.RemoveAt(i + 1);
                i--;
            }
        }
    }
    foreach (var match in matches)
    {
        Console.WriteLine(match);
    }
    Console.ReadLine();
}

Answer 1

标识符正则表达式应更改为

var IdentifierRegex = @"\b[a-zA-Z]\b";

然后，asdasdas 将不匹配，您将能够测试空结果，例如。

if (matches.Count == 0)
    Console.WriteLine("Not in grammar");    
else
{ ... }

见this IDEONE demo。

如何实现字典中没有的单词必须显示错误？

How do I implement words that are not in dictionary must shown with error?

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