implement java.util.TreeMap

classpath/java/util/TreeMap.java

@@ -0,0 +1,197 @@
+/* Copyright (c) 2008, Avian Contributors
+
+   Permission to use, copy, modify, and/or distribute this software
+   for any purpose with or without fee is hereby granted, provided
+   that the above copyright notice and this permission notice appear
+   in all copies.
+
+   There is NO WARRANTY for this software.  See license.txt for
+   details. */
+
+package java.util;
+
+public class TreeMap<K,V> implements Map<K,V> {
+  private TreeSet<MyEntry<K,V>> set;
+
+  public TreeMap(final Comparator<K> comparator) {
+    set = new TreeSet(new Comparator<MyEntry<K,V>>() {
+        public int compare(MyEntry<K,V> a, MyEntry<K,V> b) {
+          return comparator.compare(a.key, b.key);
+        }
+      });
+  }
+
+  public TreeMap() {
+    this(new Comparator<K>() {
+        public int compare(K a, K b) {
+          return ((Comparable) a).compareTo(b);
+        }
+    });
+  }
+
+  public String toString() {
+    return Collections.toString(this);
+  }
+
+  public V get(Object key) {
+    MyEntry<K,V> e = set.find(new MyEntry(key, null));
+    return e == null ? null : e.value;
+  }
+
+  public V put(K key, V value) {
+    MyEntry<K,V> e = set.addAndReplace(new MyEntry(key, value));
+    return e == null ? null : e.value;
+  }
+
+  public void putAll(Map<? extends K,? extends V> elts) {
+    for (Map.Entry<? extends K, ? extends V> entry : elts.entrySet()) {
+      put(entry.getKey(), entry.getValue());
+    }
+  }
+    
+  public V remove(Object key) {
+    MyEntry<K,V> e = set.removeAndReturn(new MyEntry(key, null));
+    return e == null ? null : e.value;
+  }
+
+  public void clear() {
+    set.clear();
+  }
+
+  public int size() {
+    return set.size();
+  }
+
+  public boolean isEmpty() {
+    return size() == 0;
+  }
+
+  public boolean containsKey(Object key) {
+    return set.contains(new MyEntry(key, null));
+  }
+
+  private boolean equal(Object a, Object b) {
+    return a == null ? b == null : a.equals(b);
+  }
+
+  public boolean containsValue(Object value) {
+    for (V v: values()) {
+      if (equal(v, value)) {
+        return true;
+      }
+    }
+    return false;
+  }
+
+  public Set<Entry<K, V>> entrySet() {
+    return (Set<Entry<K, V>>) (Set) set;
+  }
+
+  public Set<K> keySet() {
+    return new KeySet();
+  }
+
+  public Collection<V> values() {
+    return new Values();
+  }
+
+  private static class MyEntry<K,V> implements Entry<K,V> {
+    public final K key;
+    public V value;
+
+    public MyEntry(K key, V value) {
+      this.key = key;
+      this.value = value;
+    }
+
+    public K getKey() {
+      return key;
+    }
+
+    public V getValue() {
+      return value;
+    }
+
+    public void setValue(V value) {
+      this.value = value;
+    }
+  }
+
+  private class KeySet implements Set<K> {
+    public int size() {
+      return TreeMap.this.size();
+    }
+
+    public boolean isEmpty() {
+      return TreeMap.this.isEmpty();
+    }
+
+    public boolean contains(Object key) {
+      return containsKey(key);
+    }
+
+    public boolean add(K key) {
+      return set.addAndReplace(new MyEntry(key, null)) != null;
+    }
+
+    public boolean addAll(Collection<? extends K> collection) {
+      boolean change = false;
+      for (K k: collection) if (add(k)) change = true;
+      return change;
+    }
+
+    public boolean remove(Object key) {
+      return set.removeAndReturn(new MyEntry(key, null)) != null;
+    }
+
+    public <T> T[] toArray(T[] array) {
+      return Collections.toArray(this, array);      
+    }
+
+    public void clear() {
+      TreeMap.this.clear();
+    }
+
+    public Iterator<K> iterator() {
+      return new Collections.KeyIterator(set.iterator());
+    }
+  }
+
+  private class Values implements Collection<V> {
+    public int size() {
+      return TreeMap.this.size();
+    }
+
+    public boolean isEmpty() {
+      return TreeMap.this.isEmpty();
+    }
+
+    public boolean contains(Object value) {
+      return containsValue(value);
+    }
+
+    public boolean add(V value) {
+      throw new UnsupportedOperationException();
+    }
+
+    public boolean addAll(Collection<? extends V> collection) {
+      throw new UnsupportedOperationException();      
+    }
+
+    public boolean remove(Object value) {
+      throw new UnsupportedOperationException();
+    }
+
+    public <T> T[] toArray(T[] array) {
+      return Collections.toArray(this, array);      
+    }
+
+    public void clear() {
+      TreeMap.this.clear();
+    }
+
+    public Iterator<V> iterator() {
+      return new Collections.ValueIterator(set.iterator());
+    }
+  }
+}