Class MapFact

src/main/java/pascal/taie/analysis/dataflow/fact/MapFact.java:39–173

Represents map-like data-flow facts. @param type of keys @param type of values

 * @param <V> type of values
 */
public class MapFact<K, V> implements Copyable<MapFact<K, V>> {

    /**
     * The map holding the mappings of this MapFact.
     */
    protected final Map<K, V> map;

    /**
     * Constructs a new MapFact with the same mappings as specified Map.
     *
     * @param map the map whose mappings are to be placed in this map.
     */
    public MapFact(Map<K, V> map) {
        this.map = Maps.newHybridMap(map);
    }

    /**
     * @return the value to which the specified key is mapped,
     * or null if this map contains no mapping for the key.
     */
    public V get(K key) {
        return map.get(key);
    }

    /**
     * Updates the key-value mapping in this fact.
     *
     * @return if the update changes this fact.
     */
    public boolean update(K key, V value) {
        return !Objects.equals(map.put(key, value), value);
    }

    /**
     * Removes the key-value mapping for given key.
     *
     * @return the previous value associated with key,
     * or null if there was no mapping for key.
     */
    public V remove(K key) {
        return map.remove(key);
    }

    /**
     * Copies the content from given fact to this fact.
     *
     * @return true if this fact changed as a result of the call, otherwise false.
     */
    public boolean copyFrom(MapFact<K, V> fact) {
        boolean changed = false;
        for (Map.Entry<K, V> entry : fact.map.entrySet()) {
            changed |= update(entry.getKey(), entry.getValue());
        }
        return changed;
    }

    /**
     * Creates and returns a copy of this fact.