Partial grammar for counting class numbers

Question

I need to count the number of classes in the 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; }
        ; 

This analyzer correctly counts empty classes (and nested classes too) with an empty body:

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

I need to count classes with a non-empty body, for example:

class TestClass
{
    int a = 42;

    class Nested { }
}

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

int a = 42;

How can i do this? Maybe, for example, for another language?
Please help!

Answer 1

, filter=true options {...}. , , , , .

, , ( ) .

:

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')*
  ;

, Identifier , , Xclass Foo : ['X', 'class', 'Foo']. Identifier Xclass .

:

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

, , , ( #), .

!