/src/Boo.Lang/BooComparer.cs
C# | 114 lines | 73 code | 11 blank | 30 comment | 19 complexity | db4aa65461ce3c19c05a4a2b9ede7bb4 MD5 | raw file
Possible License(s): GPL-2.0
- #region license
- // Copyright (c) 2004, Rodrigo B. de Oliveira (rbo@acm.org)
- // All rights reserved.
- //
- // Redistribution and use in source and binary forms, with or without modification,
- // are permitted provided that the following conditions are met:
- //
- // * Redistributions of source code must retain the above copyright notice,
- // this list of conditions and the following disclaimer.
- // * Redistributions in binary form must reproduce the above copyright notice,
- // this list of conditions and the following disclaimer in the documentation
- // and/or other materials provided with the distribution.
- // * Neither the name of Rodrigo B. de Oliveira nor the names of its
- // contributors may be used to endorse or promote products derived from this
- // software without specific prior written permission.
- //
- // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
- // ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
- // WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
- // DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
- // FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- // DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
- // SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
- // CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
- // OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
- // THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- #endregion
- namespace Boo.Lang
- {
- using System;
- using System.Collections;
- /// <summary>
- /// Compares items lexicographically through IEnumerable whenever
- /// they don't implement IComparable.
- /// </summary>
- [Serializable]
- public class BooComparer : IComparer
- {
- public static readonly IComparer Default = new BooComparer();
- private BooComparer()
- {
- }
- public int Compare(object lhs, object rhs)
- {
- if (null == lhs)
- {
- if (null == rhs)
- {
- return 0;
- }
- return -1;
- }
- else
- {
- if (null == rhs)
- {
- return 1;
- }
- IComparable lhsComparable = lhs as IComparable;
- if (null == lhsComparable)
- {
- IComparable rhsComparable = rhs as IComparable;
- if (null == rhsComparable)
- {
- IEnumerable lhsEnumerable = lhs as IEnumerable;
- IEnumerable rhsEnumerable = rhs as IEnumerable;
- if (null != lhsEnumerable && null != rhsEnumerable)
- {
- return CompareEnumerables(lhsEnumerable, rhsEnumerable);
- }
- //throw new ArgumentException(ResourceManager.GetString("CantCompareItems"));
- return lhs.Equals(rhs) ? 0 : 1;
- }
- return -1*(rhsComparable.CompareTo(lhs));
- }
- return lhsComparable.CompareTo(rhs);
- }
- }
- int CompareEnumerables(IEnumerable lhs, IEnumerable rhs)
- {
- IEnumerator lhsEnum = lhs.GetEnumerator();
- IEnumerator rhsEnum = rhs.GetEnumerator();
- while (lhsEnum.MoveNext())
- {
- if (!rhsEnum.MoveNext())
- {
- return 1;
- }
- int value = Compare(lhsEnum.Current, rhsEnum.Current);
- if (0 == value)
- {
- continue;
- }
- return value;
- }
- if (rhsEnum.MoveNext())
- {
- return -1;
- }
- return 0;
- }
- }
- }