how to build a parser with antlr4 target golang without visitors and walkers - go

Question

I am trying to write a small parser with golang target, but not using visitors or walkers, but I am not able to find any sample code to build my parser upon.
For example, the following is the grammar code which I am trying to replicate with golang:
# Expr.g4:
grammar Expr;
#header {
}
#parser::members {
def eval(self, left, op, right):
if ExprParser.MUL == op.type:
return left * right
elif ExprParser.DIV == op.type:
return left / right
elif ExprParser.ADD == op.type:
return left + right
elif ExprParser.SUB == op.type:
return left - right
else:
return 0
}
stat: e NEWLINE {print($e.v);}
| ID '=' e NEWLINE {self.memory[$ID.text] = $e.v}
| NEWLINE
;
e returns [int v]
: a=e op=('*'|'/') b=e {$v = self.eval($a.v, $op, $b.v)}
| a=e op=('+'|'-') b=e {$v = self.eval($a.v, $op, $b.v)}
| INT {$v = $INT.int}
| ID
{
id = $ID.text
$v = self.memory.get(id, 0)
}
| '(' e ')' {$v = $e.v}
;
MUL : '*' ;
DIV : '/' ;
ADD : '+' ;
SUB : '-' ;
ID : [a-zA-Z]+ ; // match identifiers
INT : [0-9]+ ; // match integers
NEWLINE:'\r'? '\n' ; // return newlines to parser (is end-statement signal)
WS : [ \t]+ -> skip ; // toss out whitespace
And this is the python tester code for it:
# test_expr.py:
import sys
from antlr4 import *
from antlr4.InputStream import InputStream
from ExprLexer import ExprLexer
from ExprParser import ExprParser
if __name__ == '__main__':
parser = ExprParser(None)
parser.buildParseTrees = False
parser.memory = {} # how to add this to generated constructor?
line = sys.stdin.readline()
lineno = 1
while line != '':
line = line.strip()
istream = InputStream(line + "\n")
lexer = ExprLexer(istream)
lexer.line = lineno
lexer.column = 0
token_stream = CommonTokenStream(lexer)
parser.setInputStream(token_stream)
parser.stat()
line = sys.stdin.readline()
lineno += 1
Can anybody please post a sample golang code which is equivalent to the above python and inlined code?