1. /*
  2. * Copyright 1999-2004 The Apache Software Foundation.
  3. *
  4. * Licensed under the Apache License, Version 2.0 (the "License");
  5. * you may not use this file except in compliance with the License.
  6. * You may obtain a copy of the License at
  7. *
  8. * http://www.apache.org/licenses/LICENSE-2.0
  9. *
  10. * Unless required by applicable law or agreed to in writing, software
  11. * distributed under the License is distributed on an "AS IS" BASIS,
  12. * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13. * See the License for the specific language governing permissions and
  14. * limitations under the License.
  15. */
  16. /*
  17. * $Id: Minus.java,v 1.8 2004/02/17 04:35:12 minchau Exp $
  18. */
  19. package com.sun.org.apache.xpath.internal.operations;
  20. import com.sun.org.apache.xpath.internal.XPathContext;
  21. import com.sun.org.apache.xpath.internal.objects.XNumber;
  22. import com.sun.org.apache.xpath.internal.objects.XObject;
  23. /**
  24. * The binary '-' operation expression executer.
  25. */
  26. public class Minus extends Operation
  27. {
  28. /**
  29. * Apply the operation to two operands, and return the result.
  30. *
  31. *
  32. * @param left non-null reference to the evaluated left operand.
  33. * @param right non-null reference to the evaluated right operand.
  34. *
  35. * @return non-null reference to the XObject that represents the
  36. * result of the operation.
  37. *
  38. * @throws javax.xml.transform.TransformerException
  39. */
  40. public XObject operate(XObject left, XObject right)
  41. throws javax.xml.transform.TransformerException
  42. {
  43. return new XNumber(left.num() - right.num());
  44. }
  45. /**
  46. * Evaluate this operation directly to a double.
  47. *
  48. * @param xctxt The runtime execution context.
  49. *
  50. * @return The result of the operation as a double.
  51. *
  52. * @throws javax.xml.transform.TransformerException
  53. */
  54. public double num(XPathContext xctxt)
  55. throws javax.xml.transform.TransformerException
  56. {
  57. return (m_left.num(xctxt) - m_right.num(xctxt));
  58. }
  59. }