Exemple #1
0
        object IVisitor <object> .visit(BinOpNode node)
        {
            object left  = evaluate(node.getLeft());
            object right = evaluate(node.getRight());

            switch (node.value)
            {
            case "+":
                // concatenation
                if (node.getLeft().type.Equals(Token.STRING) &  node.getRight().type.Equals(Token.STRING))
                {
                    return(left.ToString() + right.ToString());
                }
                else
                {
                    return(Convert.ToInt32(left) + Convert.ToInt32(right));
                }

            case "-":
                return(Convert.ToInt32(left) - Convert.ToInt32(right));

            case "*":
                return(Convert.ToInt32(left) * Convert.ToInt32(right));

            case "/":
                return(Convert.ToInt32(left) / Convert.ToInt32(right));

            case "=":
                if (node.getLeft().type.Equals(Token.STRING) &  node.getRight().type.Equals(Token.STRING))
                {
                    return(left.ToString().Equals(right.ToString()));
                }
                else
                {
                    return(Convert.ToInt32(left) == Convert.ToInt32(right));
                }

            case "<":
                if (node.getLeft().type.Equals(Token.STRING) &  node.getRight().type.Equals(Token.STRING))
                {
                    return(left.ToString().Length < right.ToString().Length);
                }
                else
                {
                    return(Convert.ToInt32(left) < Convert.ToInt32(right));
                }

            case "&":
                return(Convert.ToBoolean(left) & Convert.ToBoolean(right));

            default:
                break;
            }
            return(null);
        }
Exemple #2
0
        object IVisitor <object> .visit(BinOpNode node)
        {
            Node left  = node.getLeft();
            Node right = node.getRight();

            // decorate
            left.type  = Convert.ToString(left.accept(this));
            right.type = Convert.ToString(right.accept(this));


            if (left.type == Token.INT && right.type == Token.INT)
            {
                node.type = Token.INT;
            }
            else if (left.type == Token.STRING || right.type == Token.STRING)
            {
                node.type = Token.STRING;
            }
            else if (left.type == Token.BOOL || right.type == Token.BOOL)
            {
                node.type = Token.BOOL;
            }

            checkOperationIsAllowed(node, left, right);
            return(node.type);
        }