Page Comparison

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Java

Code Block

grammar SimpleCalc;

tokens {
	PLUS 	= '+' ;
	MINUS	= '-' ;
	MULT	= '*' ;
	DIV	= '/' ;
}

@members {
    public static void main(String[] args) throws Exception {
        SimpleCalcLexer lex = new SimpleCalcLexer(new ANTLRFileStream(args[0]));
       	CommonTokenStream tokens = new CommonTokenStream(lex);

        SimpleCalcParser parser = new SimpleCalcParser(tokens);

        try {
            parser.expr();
        } catch (RecognitionException e)  {
            e.printStackTrace();
        }
    }
}

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

expr	: term ( ( PLUS | MINUS )  term )* ;

term	: factor ( ( MULT | DIV ) factor )* ;

factor	: NUMBER ;


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

NUMBER	: (DIGIT)+ ;

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

fragment DIGIT	: '0'..'9' ;

C#

Note: language=CSharp2 with ANTLR 3.1; ANTLR 3.0.1 uses the older CSharp target

Code Block

grammar SimpleCalc;

options {
    language=CSharp2;
}

tokens {
	PLUS 	= '+' ;
	MINUS	= '-' ;
	MULT	= '*' ;
	DIV	= '/' ;
}

@members {
    public static void Main(string[] args) {
        SimpleCalcLexer lex = new SimpleCalcLexer(new ANTLRFileStream(args[0]));
       	CommonTokenStream tokens = new CommonTokenStream(lex);

        SimpleCalcParser parser = new SimpleCalcParser(tokens);

        try {
            parser.expr();
        } catch (RecognitionException e)  {
            Console.Error.WriteLine(e.StackTrace);
        }
    }
}

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

expr	: term ( ( PLUS | MINUS )  term )* ;

term	: factor ( ( MULT | DIV ) factor )* ;

factor	: NUMBER ;


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

NUMBER	: (DIGIT)+ ;

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

fragment DIGIT	: '0'..'9' ;

Objective-C

To be written. Volunteers?

Code Block
grammar SimpleCalc; options { language=ObjC; } OR : '\|\|' ;

C

Code Block

grammar SimpleCalc;

options
{
    language=C;
}

tokens
{
	PLUS 	= '+' ;
	MINUS	= '-' ;
	MULT	= '*' ;
	DIV	= '/' ;
}

@members
{

 #include "SimpleCalcLexer.h"

 int main(int argc, char * argv[])
 {

    pANTLR3_INPUT_STREAM           input;
    pSimpleCalcLexer               lex;
    pANTLR3_COMMON_TOKEN_STREAM    tokens;
    pSimpleCalcParser              parser;

    input  = antlr3AsciiFileStreamNew          ((pANTLR3_UINT8)argv[1]);
    lex    = SimpleCalcLexerNew                (input);
    tokens = antlr3CommonTokenStreamSourceNew  (ANTLR3_SIZE_HINT, TOKENSOURCE(lex));
    parser = SimpleCalcParserNew               (tokens);

    parser  ->expr(parser);

    // Must manually clean up
    //
    parser ->free(parser);
    tokens ->free(tokens);
    lex    ->free(lex);
    input  ->close(input);

    return 0;
 }

}

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

expr	: term   ( ( PLUS | MINUS )  term   )*
        ;

term	: factor ( ( MULT | DIV   )  factor )*
        ;

factor	: NUMBER
        ;


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

NUMBER	    : (DIGIT)+
            ;

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

fragment
DIGIT	    : '0'..'9'
            ;

Python

Code Block

grammar SimpleCalc;

options {
	language = Python;
}

tokens {
	PLUS 	= '+' ;
	MINUS	= '-' ;
	MULT	= '*' ;
	DIV	= '/' ;
}

@header {
import sys
import traceback

from SimpleCalcLexer import SimpleCalcLexer
}

@main {
def main(argv, otherArg=None):
  char_stream = ANTLRFileStream(sys.argv[1])
  lexer = SimpleCalcLexer(char_stream)
  tokens = CommonTokenStream(lexer)
  parser = SimpleCalcParser(tokens);

  try:
        parser.expr()
  except RecognitionException:
	traceback.print_stack()
}

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

expr	: term ( ( PLUS | MINUS )  term )* ;

term	: factor ( ( MULT | DIV ) factor )* ;

factor	: NUMBER ;


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

NUMBER	: (DIGIT)+ ;

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

fragment DIGIT	: '0'..'9' ;

...

Code Block
java org.antlr.Tool SimpleCalc.g

ANTLR will generate source files for the lexer and parser (e.g. SimpleCalcLexer.java and SimpleCalcParser.java). Copy these into the appropriate places for your development environment and compile them.

2.3 Revisit the simple grammar and learn basic ANTLR 3 syntax

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Versions Compared

Old Version 52

New Version 53

Key

2.3 Revisit the simple grammar and learn basic ANTLR 3 syntax