| /* transformer.java -- Content model transforms. |
| Copyright (C) 2005 Free Software Foundation, Inc. |
| |
| This file is part of GNU Classpath. |
| |
| GNU Classpath 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 2, or (at your option) |
| any later version. |
| |
| GNU Classpath 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 GNU Classpath; see the file COPYING. If not, write to the |
| Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 02110-1301 USA. |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
| this exception to your version of the library, but you are not |
| obligated to do so. If you do not wish to do so, delete this |
| exception statement from your version. */ |
| |
| |
| package gnu.javax.swing.text.html.parser.models; |
| |
| import java.io.Serializable; |
| |
| import javax.swing.text.html.parser.ContentModel; |
| import javax.swing.text.html.parser.DTD; |
| |
| /** |
| * Transforms the standard ContentModel tree into the internal representation, |
| * used in this implementation. |
| * @author Audrius Meskauskas, Lithuania (AudriusA@Bioinformatics.org) |
| */ |
| public class transformer |
| implements Serializable |
| { |
| private static final long serialVersionUID = 1; |
| |
| /** |
| * All binary operators. |
| */ |
| protected static String binary = "&|,"; |
| |
| /** |
| * All unary operators. |
| */ |
| protected static String unary = "+*?"; |
| |
| /** |
| * Measure length of the linked list of the content models. |
| * @param c The heading element of the linked list. |
| * @return the length of the list (0 for null 1 if c!=null and c.next==null, |
| * etc. |
| */ |
| public static int measureChainLength(ContentModel c) |
| { |
| if (c == null) |
| return 0; |
| else |
| return measureChainLength(c.next) + 1; |
| } |
| |
| /** |
| * Transform into internal representation without usind dtd. |
| * This should be used only for testing. |
| */ |
| public static node transform(ContentModel c) |
| { |
| return transform(c, null); |
| } |
| |
| /** |
| * Transform into internal representation. |
| * @param c a model to transform |
| * @return a transformed model |
| * @throws Error if the model structure contains errors. |
| */ |
| public static node transform(ContentModel c, DTD dtd) |
| { |
| // Handle the special cases first. |
| if (c.content instanceof node) |
| return (node) c.content; |
| |
| // Do the typical transform. |
| node n; |
| |
| /* Case with the single token */ |
| if (c.next == null) |
| { |
| n = optionalTransform(c, dtd); |
| } |
| else /* Case with the chain of the multiple tokens. */ |
| { |
| node[] l = new node[ measureChainLength(c) ]; |
| ContentModel m = c; |
| for (int i = 0; i < l.length; i++) |
| { |
| if (m.content instanceof ContentModel) |
| { |
| ContentModel nested = (ContentModel) m.content; |
| if (nested.next == null && |
| !(nested.content instanceof ContentModel) |
| ) |
| { |
| l [ i ] = |
| new node((char) m.type, (char) nested.type, nested.content); |
| } |
| else |
| { |
| l [ i ] = transform(nested, dtd); |
| } |
| } |
| else |
| l [ i ] = new node((char) 0, (char) 0, m.content); |
| addtype(l [ i ], (char) m.type); |
| m = m.next; |
| } |
| |
| if (isBinary(c.type)) |
| for (int i = 0; i < l.length; i++) |
| { |
| l [ i ].binary = (char) c.type; |
| } |
| |
| n = new list(l); |
| } |
| |
| addtype(n, (char) c.type); |
| |
| return n; |
| } |
| |
| /** |
| * True for binary operator |
| * @param c a character to test |
| * @return true for [ ,&| ], false otherwise. |
| */ |
| private static boolean isBinary(int c) |
| { |
| return binary.indexOf((char) c) >= 0; |
| } |
| |
| /** |
| * True for unary operator. |
| * @param c a character to test |
| * @return true for [ +?* ], false otherwise. |
| */ |
| private static boolean isUnary(int c) |
| { |
| return unary.indexOf((char) c) >= 0; |
| } |
| |
| /** |
| * Assign an operation type for the given node. |
| * @param n A node to set the operation to. |
| * @param type Either binary or unary operation, is assigned to the |
| * corresponding field of the node. |
| * @throws error if the operation type is not |
| * representing a valid unary or binary operation. |
| */ |
| private static void addtype(node n, char type) |
| { |
| if (isBinary(type)) |
| n.binary = type; |
| |
| else if (isUnary(type)) |
| n.unary = type; |
| |
| else if (type != 0) |
| throw new Error("Invalid operation '" + (char) type + "'"); |
| } |
| |
| private static node optionalTransform(ContentModel c, DTD dtd) |
| { |
| node n; |
| if (c.content instanceof ContentModel) |
| n = transform((ContentModel) c.content, dtd); |
| else |
| |
| /* A single token with the specified operation */ |
| n = new node((char) 0, (char) 0, c.content); |
| return n; |
| } |
| } |