Implement IF Else for, while loop and logical Statement in Antr - antlr

Question

I am new to ANTLR and I am trying to implement if-else, for, while loop and logical symbol, but I am not able to do so. Can Anyone help me with this? Below is what I have done.
grammar BasForCCAL;
#header {
package basforccal;
import java.util.HashMap;
import java.util.Scanner;
}
#lexer::header{
package basforccal;
}
#members{
String programName;
HashMap memory = new HashMap();
public void checkName(String endName){
if(!endName.equals(programName)){
System.out.println("Wrong Program name in end of the program");
}
}
}
program : start programbody end;
start :'PROGRAM' ID {programName = $ID.text ; System.out.println("Checking program :"+$ID.text);};
programbody
: (devcar|ID'='(expr|CHAR)| ctrlStmt)*;
devcar : initInt var1|
intFloat var1|
intChar var1 ;
initInt : 'INT'
;
intFloat
: 'FLOAT'
;
intChar: 'CHAR';
var1 : idname (',' var1)* ;
idname : ID {Integer v = (Integer)memory.get($ID.text);
if(v!=null)
{System.err.println("Error: "+$ID.text+" already defined line:"+$ID.getLine());}
else
{memory.put($ID.text,new Integer('1'));}
}
;
expr
: (multExpr |'('expr')')
( '+' multExpr
| '-' multExpr
| '/' multExpr
| '*' multExpr
)*
;
logiExpr
: expr relOpr expr;
relOpr
: '<'
| '>'
| '<>'
| '<='
| '>='
;
ctrlStmt
: 'IF''('logiExpr')' 'THEN' (stat)+ 'ENDIF'
| 'WHILE''('logiExpr')' 'DO' (stat)+ 'ENDDO'
| 'FOR' ID '=' expr 'TO' expr 'LOOP' stat+ 'ENDLOOP';
stat
: ctrlStmt|multExpr
| ID '=' (expr|CHAR);
multExpr
: ID {
Integer v = (Integer)memory.get($ID.text);
if ( v!=null ){}
else System.err.println("undefined variable "+$ID.text);
}
| INT
| FLOAT
;
end
: 'END' ID '.' {checkName($ID.text);};
My Java code to check it.
import org.antlr.runtime.ANTLRFileStream;
import org.antlr.runtime.CommonTokenStream;
import org.antlr.runtime.RecognitionException;
import java.io.IOException;
public class AntlrParser {
public static void main(String args[]) throws IOException, RecognitionException {
basforccal.BasForCCALLexer lexer = new basforccal.BasForCCALLexer(new ANTLRFileStream(args[0]));
CommonTokenStream token = new CommonTokenStream(lexer);
basforccal.BasForCCALParser parser = new basforccal.BasForCCALParser(token);
parser.program();
}
}
Below is the program in a file(prog1.bfcc) which I am trying to check using my Java code.
PROGRAM TESTIF
FLOAT A,B,C
A=1.0
C=1.0
IF(A>1.0)THEN
B=2.0
ENDIF
IF(B*C<=10)THEN
IF(A>0.0)THEN
C=5.0
ENDIF
ENDIF=
IF(3=4)THEN
A=1.0
B=2.0
C=3.0
ENDIF
END TESTIF.
Below is the error which I am getting while checking it from JAVA.
Checking program :TESTIF
C:\Users\vivek\IdeaProjects\BasForCCal\prog1.bfcc line 16:4 mismatched input '=' expecting set null
Process finished with exit code 0

Answer 1

You have ENDIF= in your input, which looks suspicious. It should probably be: ENDIF without the =. This is what the error message is trying to tell you.
Also, there is IF(3=4)THEN in your input, but your relOpr does not inlcude the = operator. You should probably add that to it:
relOpr
: '='
| '<'
| '>'
| '<>'
| '<='
| '>='
;