001    package org.maltparser.ml.lib;
002    
003    import java.util.ArrayList;
004    
005    
006    /**
007     * The feature list is sorted according to the compareTo of the node.
008     * 
009     * @author Johan Hall
010     *
011     */
012    public class FeatureList  {
013            private static final long serialVersionUID = 7526471155622776147L;
014            private final ArrayList<MaltFeatureNode> list;
015            
016            /**
017             * Creates a feature list of MaltFeatureNode objects
018             */
019            public FeatureList() {
020                    list = new ArrayList<MaltFeatureNode>();
021            }
022            
023            /**
024             * Creates a feature list of MaltFeatureNode objects
025             */
026            public FeatureList(int size) {
027                    list = new ArrayList<MaltFeatureNode>(size);
028            }
029            
030            /**
031             * Adds a MaltFeatureNode object to the feature list. The object will be added in the sorted feature list based on 
032             * the compareTo() in MaltFeatureNode.
033             * 
034             * @param x a MaltFeatureNode object
035             */
036            public void add(MaltFeatureNode x) {
037                    if (list.size() == 0) {
038                            list.add(x);
039                    } else {
040                    int low = 0;
041                    int high = list.size() - 1;
042                    int mid;
043                    
044                    while( low <= high ) {
045                        mid = (low + high) / 2;
046            
047                        if( list.get(mid).compareTo(x) < 0 ) {
048                            low = mid + 1;
049                        } else if( list.get(mid).compareTo(x) > 0 ) {
050                            high = mid - 1;
051                        } else {
052                            break;
053                        }
054                    }
055                    list.add(low,x);
056                    }
057            }
058            
059            /**
060             * Adds an index/value pair to the feature list.
061             * 
062             * @param index a binarized feature index
063             * @param value a value 
064             */
065            public void add(int index, double value) {
066                    add(new MaltFeatureNode(index,value));
067            }
068            
069            /**
070             * @param i the position in the feature list
071             * @return a MaltFeatureNode object located on the position <i>i</i>
072             */
073            public MaltFeatureNode get(int i) {
074                    if (i < 0 || i >= size()) {
075                            return null;
076                    }
077                    return list.get(i);
078            }
079            
080            /**
081             * Clears the feature list
082             */
083            public void clear() {
084                    list.clear();
085            }
086            
087            /**
088             * @return the size of the feature list
089             */
090            public int size() {
091                    return list.size();
092            }
093            
094            public MaltFeatureNode[] toArray() {
095                    final MaltFeatureNode[] nodes = new MaltFeatureNode[list.size()];
096                    final int len = nodes.length;
097                    for (int i = 0; i < len; i++) {
098                            nodes[i] = list.get(i);
099                    }
100                    return nodes;
101            }
102    }