cn.taketoday.expression.spel.ast.OpLT Maven / Gradle / Ivy

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/*
 * Original Author -> Harry Yang ([email protected]) https://taketoday.cn
 * Copyright © TODAY & 2017 - 2022 All Rights Reserved.
 *
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see [http://www.gnu.org/licenses/]
 */

package cn.taketoday.expression.spel.ast;

import java.math.BigDecimal;
import java.math.BigInteger;

import cn.taketoday.bytecode.MethodVisitor;
import cn.taketoday.expression.EvaluationException;
import cn.taketoday.bytecode.core.CodeFlow;
import cn.taketoday.expression.spel.ExpressionState;
import cn.taketoday.expression.spel.support.BooleanTypedValue;
import cn.taketoday.util.NumberUtils;

/**
 * Implements the less-than operator.
 *
 * @author Andy Clement
 * @author Juergen Hoeller
 * @author Giovanni Dall'Oglio Risso
 * @since 4.0
 */
public class OpLT extends Operator {

  public OpLT(int startPos, int endPos, SpelNodeImpl... operands) {
    super("<", startPos, endPos, operands);
    this.exitTypeDescriptor = "Z";
  }

  @Override
  public BooleanTypedValue getValueInternal(ExpressionState state) throws EvaluationException {
    Object left = getLeftOperand().getValueInternal(state).getValue();
    Object right = getRightOperand().getValueInternal(state).getValue();

    this.leftActualDescriptor = CodeFlow.toDescriptorFromObject(left);
    this.rightActualDescriptor = CodeFlow.toDescriptorFromObject(right);

    if (left instanceof Number leftNumber && right instanceof Number rightNumber) {
      if (leftNumber instanceof BigDecimal || rightNumber instanceof BigDecimal) {
        BigDecimal leftBigDecimal = NumberUtils.convertNumberToTargetClass(leftNumber, BigDecimal.class);
        BigDecimal rightBigDecimal = NumberUtils.convertNumberToTargetClass(rightNumber, BigDecimal.class);
        return BooleanTypedValue.forValue(leftBigDecimal.compareTo(rightBigDecimal) < 0);
      }
      else if (leftNumber instanceof Double || rightNumber instanceof Double) {
        return BooleanTypedValue.forValue(leftNumber.doubleValue() < rightNumber.doubleValue());
      }
      else if (leftNumber instanceof Float || rightNumber instanceof Float) {
        return BooleanTypedValue.forValue(leftNumber.floatValue() < rightNumber.floatValue());
      }
      else if (leftNumber instanceof BigInteger || rightNumber instanceof BigInteger) {
        BigInteger leftBigInteger = NumberUtils.convertNumberToTargetClass(leftNumber, BigInteger.class);
        BigInteger rightBigInteger = NumberUtils.convertNumberToTargetClass(rightNumber, BigInteger.class);
        return BooleanTypedValue.forValue(leftBigInteger.compareTo(rightBigInteger) < 0);
      }
      else if (leftNumber instanceof Long || rightNumber instanceof Long) {
        return BooleanTypedValue.forValue(leftNumber.longValue() < rightNumber.longValue());
      }
      else if (leftNumber instanceof Integer || rightNumber instanceof Integer) {
        return BooleanTypedValue.forValue(leftNumber.intValue() < rightNumber.intValue());
      }
      else if (leftNumber instanceof Short || rightNumber instanceof Short) {
        return BooleanTypedValue.forValue(leftNumber.shortValue() < rightNumber.shortValue());
      }
      else if (leftNumber instanceof Byte || rightNumber instanceof Byte) {
        return BooleanTypedValue.forValue(leftNumber.byteValue() < rightNumber.byteValue());
      }
      else {
        // Unknown Number subtypes -> best guess is double comparison
        return BooleanTypedValue.forValue(leftNumber.doubleValue() < rightNumber.doubleValue());
      }
    }

    if (left instanceof CharSequence && right instanceof CharSequence) {
      left = left.toString();
      right = right.toString();
    }

    return BooleanTypedValue.forValue(state.getTypeComparator().compare(left, right) < 0);
  }

  @Override
  public boolean isCompilable() {
    return isCompilableOperatorUsingNumerics();
  }

  @Override
  public void generateCode(MethodVisitor mv, CodeFlow cf) {
    generateComparisonCode(mv, cf, IFGE, IF_ICMPGE);
  }

}