C＃中的MDX解析器＃

Question

我需要使用我的.Net應用程序解析MDX。最初，我使用正則表達式來做到這一點，但表達式變得複雜了，一位正則表達式專家建議如果我使用解析器會更好。

是否有專門針對MDX的解析器？我嘗試過Ranet，但由於某些未知的原因，它沒有安裝在我的機器上（不顯示任何錯誤信息）。

我需要將MDX的多個部分拆分爲字符串。例如，在另一個等

Answer 1

最好的解決方案是找到解析器，但總是很難找到解析器來滿足您的特定需求。因此，如果最終編寫解析器Ve Parser與正則表達式相比是一個更好的工具，因爲它提供了更多的解析功能，您可以生成更好的輸出，並且由於您調用.net方法，它隱含地具有編寫解析器的智能特性。 缺點是它還沒有很好的記錄，所以你可能會發現一些特殊情況下很難。

項目鏈接：http://veparser.codeplex.com

的NuGet標識符：veparser

如果你需要得到文本的MDX的不同部分在這裏是部分示例代碼：

using VeParser; 
using System.Linq; 
using System.Collections.Generic; 
using System; 


public class MDXParser : TokenParser 
{ 
    protected override Parser GetRootParser() 
    { 
     // read the following line as : fill 'select' property of 'current object(which is a statement)' with the 'new value of selectStatement' after facing a sequence of a select statement and then the symbol of (and then a delemitied list of identierfiers filling the 'fileds' property of 'current selectStatement object' delemitied by ',' and finally expect the sequence to be finished with a symbol of ')' 
     var selectStatement = fill("select", create<selectStatment>(seq(expectKeyword_of("select"), expectSymbol_of("("), deleimitedList(expectSymbol_of(","), fill("fields",identifier)), expectSymbol_of(")")))); 
     // read the following line as : fill the from property of 'current object(which is a statement)' with an expected identifier that is after a 'from' keyword 
     var fromStatement = seq(expectKeyword_of("from"), fill("from", identifier)); 
     // the following statement is incomplete, as I just wanted to show a sample bit, If you are interested I can help you complete the parser until the full documentation become available. 
     var whereStatement = fill("where", create<whereStatement>(seq(expectKeyword_of("where")))); 
     var statement = create<statement>(seq(selectStatement, fromStatement, whereStatement)); 

     return statement; 
    } 

    public statement Parse(string code) 
    { 
     var keywords = new[] { "select", "where", "from" }; 
     var symbols = new[] { "(",")", ".", "[", "]" }; 
     var tokenList = Lexer.Parser(code, keywords, symbols, ignoreWhireSpaces : true); 
     // Now we have our string input converted into a list of tokens which actually is a list of words but with some additional information about any word, for example a "select" is marked as keyword 
     var parseResult = base.Parse(tokenList.tokens); 
     if (parseResult == null) 
      throw new Exception("Invalid Code, at the moment Ve Parser does not support any error reporting feature."); 
     else 
      return (statement)parseResult; 
    } 
} 
public class statement 
{ 
    public selectStatment select; 
    public string where; 
    public identifier from; 
} 
public class selectStatment 
{ 
    public List<identifier> fields; 
} 
public class whereStatement 
{ 

} 

此代碼是不完整，我只想演示如何使用Ve Parser爲MDX編寫自己的解析器。如果您喜歡圖書館並想使用它，我很樂意爲您提供您需要的所有說明和技巧。

Answer 2

在where子句中一個字符串，from子句你可以看看解析器生成像http://grammatica.percederberg.net/

雖然這是艱苦的工作，制定語法，並保持及時更新。