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Diffstat (limited to 'gnu/javax/swing/text/html/parser/models/transformer.java')
| -rw-r--r-- | gnu/javax/swing/text/html/parser/models/transformer.java | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/gnu/javax/swing/text/html/parser/models/transformer.java b/gnu/javax/swing/text/html/parser/models/transformer.java new file mode 100644 index 000000000..c8c4a2544 --- /dev/null +++ b/gnu/javax/swing/text/html/parser/models/transformer.java @@ -0,0 +1,201 @@ +/* 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., 59 Temple Place, Suite 330, Boston, MA +02111-1307 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; + } +} |