| /******************************************************************************* |
| * Copyright (c) 2000, 2004 IBM Corporation and others. |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Common Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/cpl-v10.html |
| * |
| * Contributors: |
| * IBM Corporation - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.compare.rangedifferencer; |
| |
| /** |
| * For breaking an object to compare into a sequence of comparable entities. |
| * <p> |
| * It is used by <code>RangeDifferencer</code> to find longest sequences of |
| * matching and non-matching ranges. |
| * <p> |
| * For example, to compare two text documents and find longest common sequences |
| * of matching and non-matching lines, the implementation must break the document |
| * into lines. <code>getRangeCount</code> would return the number of lines in the |
| * document, and <code>rangesEqual</code> would compare a specified line given |
| * with one in another <code>IRangeComparator</code>. |
| * </p> |
| * <p> |
| * Clients should implement this interface; there is no standard implementation. |
| * </p> |
| */ |
| public interface IRangeComparator { |
| |
| /** |
| * Returns the number of comparable entities. |
| * |
| * @return the number of comparable entities |
| */ |
| int getRangeCount(); |
| |
| /** |
| * Returns whether the comparable entity given by the first index |
| * matches an entity specified by the other <code>IRangeComparator</code> and index. |
| * |
| * @param thisIndex the index of the comparable entity within this <code>IRangeComparator</code> |
| * @param other the IRangeComparator to compare this with |
| * @param otherIndex the index of the comparable entity within the other <code>IRangeComparator</code> |
| * @return <code>true</code> if the comparable entities are equal |
| */ |
| boolean rangesEqual(int thisIndex, IRangeComparator other, int otherIndex); |
| |
| /** |
| * Returns whether a comparison should be skipped because it would be too costly (or lengthy). |
| * |
| * @param length a number on which to base the decision whether to return |
| * <code>true</code> or <code>false</code> |
| * @param maxLength another number on which to base the decision whether to return |
| * <code>true</code> or <code>false</code> |
| * @param other the other <code>IRangeComparator</code> to compare with |
| * @return <code>true</code> to avoid a too lengthy range comparison |
| */ |
| boolean skipRangeComparison(int length, int maxLength, IRangeComparator other); |
| } |