计数类计数的部分语法 [英] Partial grammar for counting class count

问题描述

我需要计算在正确的C＃源文件中的类数。
我写了以下语法：

I need to count the number of classes in correct C# source file. I wrote the following grammar:

grammar CSharpClassGrammar;

options
{
        language=CSharp2;

}

@parser::namespace { CSharpClassGrammar.Generated }
@lexer::namespace  { CSharpClassGrammar.Generated }

@header
{
        using System;
        using System.Collections.Generic;

}

@members
{
        private List<string> _classCollector = new List<string>();
        public List<string> ClassCollector { get { return
_classCollector; } }

}

/*------------------------------------------------------------------
 * PARSER RULES
 *------------------------------------------------------------------*/

csfile  : class_declaration* EOF
        ;

class_declaration
        : (ACCESSLEVEL | MODIFIERS)* PARTIAL? 'class' CLASSNAME
          class_body
          ';'?
          { _classCollector.Add($CLASSNAME.text); }
        ;

class_body
        : '{' class_declaration* '}'
        ;

/*------------------------------------------------------------------
 * LEXER RULES
 *------------------------------------------------------------------*/

ACCESSLEVEL
        : 'public' | 'internal' | 'protected' | 'private' | 'protected
internal'
        ;

MODIFIERS
        : 'static' | 'sealed' | 'abstract'
        ;

PARTIAL
        : 'partial'
        ;

CLASSNAME
        : ('a'..'z'|'A'..'Z'|'_') ('a'..'z'|'A'..'Z'|'0'..'9'|'_')*
        ;

COMMENT
        : '//' ~('\n'|'\r')* {$channel=HIDDEN;}
        |   '/*' ( options {greedy=false;} : . )* '*/' {$channel=HIDDEN;}
        ;

WHITESPACE
        : ( '\t' | ' ' | '\r' | '\n'| '\u000C' )+ { $channel = HIDDEN; }
        ; 

此解析器正确计算空类（以及嵌套类）与空类实体：

This parser correctly count empty classes (and nested classes too) with empty class-body:

internal class DeclarationClass1
{
    class DeclarationClass2
    {
        public class DeclarationClass3
        {
            abstract class DeclarationClass4
            {
            }
        }
    }
}

我需要计算非空的类，例如：

I need to count classes with not empty body, such as:

class TestClass
{
    int a = 42;

    class Nested { }
}

忽略所有的代码是不是类声明。
在上面的例子中，忽略

I need to somehow ignore all the code that is "not a class declaration". In the example above ignore

int a = 42;

我该如何做？可能是其他语言的示例吗？

请帮忙！

How can I do this? May be example for other language?
Please, help!

推荐答案

当您只对某个源文件的某些部分感兴趣时，可以设置 filter = true 部分中的选项{...} 这将使您只定义那些您感兴趣的令牌，以及您未定义的令牌，被词法分析器忽略。

When you're only interested in certain parts of a source file, you could set filter=true in your options { ... } sections. This will enable you to only define those tokens you're interested in, and what you don't define, is ignored by the lexer.

请注意，这仅适用于

一个小演示：

lexer grammar CSharpClassLexer;

options {
  language=CSharp2;
  filter=true;
}

@namespace { Demo }

Comment
  :  '//' ~('\r' | '\n')*
  |  '/*' .* '*/'
  ;

String
  :  '"' ('\\' . | ~('"' | '\\' | '\r' | '\n'))* '"'
  |  '@' '"' ('"' '"' | ~'"')* '"'
  ;

Class
  :  'class' Space+ Identifier 
     {Console.WriteLine("Found class: " + $Identifier.text);}
  ;

Space
  :  ' ' | '\t' | '\r' | '\n'
  ;

Identifier
  :  ('a'..'z' | 'A'..'Z' | '_') ('a'..'z' | 'A'..'Z' | '_' | '0'..'9')*
  ;

请务必将标识符因为你不想将 Xclass Foo 标记为： ['X'，'class'，'Foo'] 。在标识符中， Xclass 将成为整个标识符。

It's important you leave the Identifier in there because you don't want Xclass Foo to be tokenized as: ['X', 'class', 'Foo']. With the Identifier in there, Xclass will become the entire identifier.

语法可以用以下类测试：

The grammar can be tested with the following class:

using System;
using Antlr.Runtime;

namespace Demo
{
    class MainClass
    {
        public static void Main (string[] args)
        {
            string source = 
@"class TestClass
{
    int a = 42;

    string _class = ""inside a string literal: class FooBar {}..."";

    class Nested { 
        /* class NotAClass {} */

        // class X { }

        class DoubleNested {
            string str = @""
                multi line string 
                class Bar {}
            "";
        }
    }
}";
            Console.WriteLine("source=\n" + source + "\n-------------------------");
            ANTLRStringStream Input = new ANTLRStringStream(source);
            CSharpClassLexer Lexer = new CSharpClassLexer(Input);
            CommonTokenStream Tokens = new CommonTokenStream(Lexer);
            Tokens.GetTokens();
        }
    }
}

source=
class TestClass
{
    int a = 42;

    string _class = "inside a string literal: class FooBar {}...";

    class Nested { 
        /* class NotAClass {} */

        // class X { }

        class DoubleNested {
            string str = @"
                multi line string 
                class Bar {}
            ";
        }
    }
}
-------------------------
Found class: TestClass
Found class: Nested
Found class: DoubleNested

只是一个快速演示，我不知道如果我在语法中处理正确的字符串文字（我不熟悉C＃），但这个演示应该给你一个开始。

Note that this is just a quick demo, I am not sure if I handled the proper string literals in the grammar (I am unfamiliar with C#), but this demo should give you a start.

祝你好运！

这篇关于计数类计数的部分语法的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！