| /* list.java -- |
| 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; |
| |
| /** |
| * Part of the internal representation of the content model. |
| * @author Audrius Meskauskas, Lithuania (AudriusA@Bioinformatics.org) |
| */ |
| public class list |
| extends node |
| implements Serializable |
| { |
| private static final long serialVersionUID = 1; |
| |
| /** |
| * Setting to true means that the list nodes must always be connected |
| * by the same operation. This is far safer and clearer, but not |
| * required by default standard. |
| */ |
| public static boolean CLEAR; |
| |
| /** |
| * A list of nodes. |
| */ |
| public final node[] nodes; |
| |
| /** |
| * Creates a new model list that is a member of some enclosing list. |
| * @param binary_operator An operator with that this list is connected |
| * with other members of the enclosing list. |
| * @param unary_operator The unary operator for this list. |
| * @param a_nodes The nodes inside this list. |
| */ |
| public list(char binary_operator, char unary_operator, node[] a_nodes) |
| { |
| super(binary_operator, unary_operator, a_nodes); |
| nodes = a_nodes; |
| } |
| |
| /** |
| * Creates a new model list. Assigns the previous field. |
| * @param a_nodes The nodes for this list. |
| * @throws an error if the node elements are connected by the |
| * different operations. This is not supported, use grouping. |
| */ |
| public list(node[] a_nodes) |
| throws Error |
| { |
| this(',', (char) 0, a_nodes); |
| |
| int operation = nodes [ 0 ].binary; |
| |
| for (int i = 0; i < nodes.length; i++) |
| { |
| if (CLEAR && nodes [ i ].binary != operation) |
| throw new Error("List members can only be connected by " + |
| "the same operation, use grouping" |
| ); |
| |
| if (i > 0) |
| nodes [ i ].previous = nodes [ i - 1 ]; |
| } |
| } |
| |
| /** |
| * Returns true if all members in the list are closed. |
| */ |
| public boolean isClosed() |
| { |
| if (super.isClosed()) |
| return true; |
| for (int i = 0; i < nodes.length; i++) |
| { |
| if (!nodes [ i ].isClosed()) |
| return false; |
| } |
| return true; |
| } |
| |
| /** |
| * Find the token that could match as the next token in |
| * the token list. |
| * |
| * @return Such token object or null if none is found. |
| */ |
| public Object findFreeNode() |
| { |
| Object fn; |
| for (int j = 0; j < nodes.length; j++) |
| { |
| if (!nodes [ j ].isClosed()) |
| { |
| fn = nodes [ j ].findFreeNode(); |
| if (fn != null) |
| return fn; |
| } |
| } |
| return null; |
| } |
| |
| /** |
| * Tries to match this list agains the given token sequence. |
| * @param tokens the sequence of the tokens to match. |
| * @return true if the valid match is found. |
| */ |
| public boolean matches(Object[] tokens) |
| { |
| reset(); |
| |
| Object x; |
| boolean m; |
| boolean matched = false; |
| |
| for (int i = 0; i < tokens.length; i++) |
| { |
| matched = false; |
| x = tokens [ i ]; |
| |
| nodescan: |
| for (int j = 0; j < nodes.length; j++) |
| { |
| if (!nodes [ j ].isClosed()) |
| { |
| m = nodes [ j ].performMatch(x); |
| |
| if (m) |
| { |
| matched = true; |
| break nodescan; |
| } |
| } |
| } |
| if (!matched) |
| return false; |
| } |
| |
| boolean valid = true; |
| |
| for (int i = 0; i < nodes.length; i++) |
| { |
| if (!nodes [ i ].valid()) |
| valid = false; |
| } |
| |
| return valid; |
| } |
| |
| /** |
| * The list never closes, despite it is trated as closed |
| * if all members in the list are closed. |
| * @return false. |
| */ |
| public boolean mustClose() |
| { |
| return false; |
| } |
| |
| /** |
| * Perform a match operation for the single token |
| * against this list. |
| * @param token a token to match. |
| * @return true if the match is found. |
| */ |
| public boolean performMatch(Object token) |
| { |
| boolean ok = false; |
| Matching: |
| for (int i = 0; i < nodes.length; i++) |
| { |
| ok = nodes [ i ].performMatch(token); |
| |
| if (ok) |
| break Matching; |
| } |
| |
| if (ok) |
| matches(); |
| |
| return ok; |
| } |
| |
| /** |
| * Prepeares the list for the next matching operation. |
| */ |
| public void reset() |
| { |
| super.reset(); |
| for (int i = 0; i < nodes.length; i++) |
| nodes [ i ].reset(); |
| } |
| |
| /** |
| * Check if the provided token can match as a next token in the |
| * list. In the case of match, the list state changes, moving |
| * current position after the matched token. However if this method |
| * returns a suggested new token to insert before the provided one, |
| * the state of the list does not change. |
| * @return Boolean.TRUE if the match is found, |
| * Boolean.FALSE if the match is not possible and no token can be |
| * inserted to make the match valid. Otherwise, returns the |
| * token object that can be inserted before the last token in the |
| * list, probably (not for sure) making the match valid. |
| * If the object is an instance of Element or TagElement, |
| * it is first ensured that the object flag "omit start" is set. |
| */ |
| public Object show(Object x) |
| { |
| boolean m; |
| boolean matched = false; |
| |
| nodescan: |
| for (int j = 0; j < nodes.length; j++) |
| { |
| if (!nodes [ j ].isClosed()) |
| { |
| m = nodes [ j ].performMatch(x); |
| |
| if (m) |
| { |
| matched = true; |
| break nodescan; |
| } |
| else |
| { |
| // For comma operation, only first not closed |
| // node must be tested for a match. |
| // unless it allows matching zero times. |
| if (binary == ',' && |
| !(nodes [ j ].unary == '?' || nodes [ j ].unary == '*') |
| ) |
| break nodescan; |
| } |
| } |
| } |
| |
| if (!matched) |
| { |
| // Find and return that would be matched. |
| Object freeNode = findFreeNode(); |
| if (freeNode == null) |
| return Boolean.FALSE; |
| else |
| return freeNode; |
| } |
| |
| for (int i = 0; i < nodes.length; i++) |
| if (!nodes [ i ].validPreliminary()) |
| { |
| return Boolean.FALSE; |
| } |
| |
| return Boolean.TRUE; |
| } |
| |
| /** |
| * Returns a string representation of the list. |
| * @return String representation, similar to BNF expression. |
| */ |
| public String toString() |
| { |
| StringBuffer b = new StringBuffer(); |
| b.append(" ( "); |
| for (int i = 0; i < nodes.length; i++) |
| { |
| if (i > 0) |
| b.append(" " + (char) nodes [ i ].binary + " "); |
| b.append(nodes [ i ]); |
| } |
| |
| b.append(" )"); |
| if (unary != 0) |
| b.append((char) unary); |
| else |
| b.append(' '); |
| return b.toString(); |
| } |
| |
| /** |
| * Returns true if all memebers in the list are valid. |
| */ |
| public boolean valid() |
| { |
| for (int i = 0; i < nodes.length; i++) |
| { |
| if (!nodes [ i ].valid()) |
| return false; |
| } |
| return true; |
| } |
| |
| /** |
| * Returns true if all memebers in the list are either valid |
| * or unvisited. The unvisited members can become valid after |
| * more tokens will be shown. |
| */ |
| public boolean validPreliminary() |
| { |
| if (silenceAllowed()) |
| { |
| boolean everVisited = false; |
| for (int i = 0; i < nodes.length; i++) |
| { |
| if (nodes [ i ].visits > 0) |
| { |
| everVisited = true; |
| break; |
| } |
| } |
| if (!everVisited) |
| return true; |
| } |
| |
| for (int i = 0; i < nodes.length; i++) |
| { |
| if (!nodes [ i ].validPreliminary()) |
| return false; |
| } |
| return true; |
| } |
| |
| /** |
| * Closes all members in the list. |
| */ |
| protected void close() |
| { |
| super.close(); |
| for (int i = 0; i < nodes.length; i++) |
| { |
| nodes [ i ].close(); |
| } |
| } |
| |
| /** |
| * Compare given token with the token of this node. |
| * If the token represents a <code>list</code>, the call may be |
| * delegeted to the child subnodes. |
| * @param a_token A token to compare. |
| * @return True if the token matches the token of this node. |
| */ |
| protected boolean compare(Object a_token) |
| { |
| return performMatch(a_token); |
| } |
| } |