public ExprNode ParseEqualityExpression()
{
var exp = new EqualityExpression
{
Token = Next(),
LeftExpression = ParseRelationalExpression()
};
if (Next().IsNot(TokenType.Equal) && Next().IsNot(TokenType.NotEqual))
return exp.LeftExpression;
exp.Operator = Next().Type;
Consume();
exp.RightExpression = ParseEqualityExpression();
return exp;
}