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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * The Universal Permissive License (UPL), Version 1.0
 *
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 * person obtaining a copy of this software, associated documentation and/or
 * data (collectively the "Software"), free of charge and under any and all
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 * freely licensable by each licensor hereunder covering either (i) the
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 * the Larger Works (as defined below), to deal in both
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 * (a) the Software, and
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 * (b) any piece of software and/or hardware listed in the lrgrwrks.txt file if
 * one is included with the Software each a "Larger Work" to which the Software
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 * Software and the Larger Work(s), and to sublicense the foregoing rights on
 * either these or other terms.
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 * This license is subject to the following condition:
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package com.oracle.truffle.sl.nodes.expression.demo;

import com.oracle.truffle.api.ExactMath;
import com.oracle.truffle.api.dsl.UnsupportedSpecializationException;
import com.oracle.truffle.api.frame.VirtualFrame;
import com.oracle.truffle.api.nodes.Node;
import com.oracle.truffle.sl.nodes.SLExpressionNode;
import com.oracle.truffle.sl.nodes.expression.SLAddNode;
import java.math.BigInteger;

/**
 * This is an example how the add operation would be implemented without specializations and without
 * the Truffle DSL. Do not write such code in your language! See {@link SLAddNode} how the add
 * operation is implemented correctly.
 */
public class SLAddWithoutSpecializationNode extends SLExpressionNode {

    @Child private SLExpressionNode leftNode;
    @Child private SLExpressionNode rightNode;

    public SLAddWithoutSpecializationNode(SLExpressionNode leftNode, SLExpressionNode rightNode) {
        super(null);
        this.leftNode = leftNode;
        this.rightNode = rightNode;
    }

    @Override
    public Object executeGeneric(VirtualFrame frame) {
        /* Evaluate the child nodes. */
        Object left = leftNode.executeGeneric(frame);
        Object right = rightNode.executeGeneric(frame);

        if (left instanceof Long && right instanceof Long) {
            /* Fast path of the arbitrary-precision arithmetic. We need to check for overflows */
            try {
                return ExactMath.addExact((Long) left, (Long) right);
            } catch (ArithmeticException ex) {
                /* Fall through to BigInteger case. */
            }
        }

        /* Implicit type conversions. */
        if (left instanceof Long) {
            left = BigInteger.valueOf((Long) left);
        }
        if (right instanceof Long) {
            right = BigInteger.valueOf((Long) right);
        }
        if (left instanceof BigInteger && right instanceof BigInteger) {
            /* Slow path of the arbitrary-precision arithmetic. */
            return ((BigInteger) left).add((BigInteger) right);
        }

        /* String concatenation if either the left or the right operand is a String. */
        if (left instanceof String || right instanceof String) {
            return left.toString() + right.toString();
        }

        /* Type error. */
        throw new UnsupportedSpecializationException(this, new Node[]{leftNode, rightNode}, new Object[]{left, right});
    }
}