cern.colt.map
Class AbstractIntObjectMap

java.lang.Object
  cern.colt.PersistentObject
      cern.colt.map.AbstractMap
          cern.colt.map.AbstractIntObjectMap

All Implemented Interfaces:

Cloneable, Serializable

Direct Known Subclasses:

OpenIntObjectHashMap

public abstract class AbstractIntObjectMap

extends AbstractMap

Abstract base class for hash maps holding (key,value) associations of type (int-->Object). First see the package summary and javadoc tree view to get the broad picture.

Implementation:

Almost all methods are expressed in terms of forEachKey(IntProcedure). As such they are fully functional, but inefficient. Override them in subclasses if necessary.

Version:

1.0, 09/24/99

See Also:

HashMap, Serialized Form

containsKey

public boolean containsKey(int key)

Returns true if the receiver contains the specified key.

Returns:

true if the receiver contains the specified key.

containsValue

public boolean containsValue(Object value)

Returns true if the receiver contains the specified value. Tests for identity.

Returns:

true if the receiver contains the specified value.

copy

public AbstractIntObjectMap copy()

Returns a deep copy of the receiver; uses clone() and casts the result.

Returns:

a deep copy of the receiver.

equals

public boolean equals(Object obj)

Compares the specified object with this map for equality. Returns true if the given object is also a map and the two maps represent the same mappings. More formally, two maps m1 and m2 represent the same mappings iff

 m1.forEachPair(
		new IntObjectProcedure() {
			public boolean apply(int key, Object value) {
				return m2.containsKey(key) && m2.get(key) == value;
			}
		}
	)
 &&
 m2.forEachPair(
		new IntObjectProcedure() {
			public boolean apply(int key, Object value) {
				return m1.containsKey(key) && m1.get(key) == value;
			}
		}
	);
 

This implementation first checks if the specified object is this map; if so it returns true. Then, it checks if the specified object is a map whose size is identical to the size of this set; if not, it it returns false. If so, it applies the iteration as described above.

Parameters:

obj - object to be compared for equality with this map.

Returns:

true if the specified object is equal to this map.

forEachKey

public abstract boolean forEachKey(IntProcedure procedure)

Applies a procedure to each key of the receiver, if any. Note: Iterates over the keys in no particular order. Subclasses can define a particular order, for example, "sorted by key". All methods which can be expressed in terms of this method (most methods can) must guarantee to use the same order defined by this method, even if it is no particular order. This is necessary so that, for example, methods keys and values will yield association pairs, not two uncorrelated lists.

Parameters:

procedure - the procedure to be applied. Stops iteration if the procedure returns false, otherwise continues.

Returns:

false if the procedure stopped before all keys where iterated over, true otherwise.

forEachPair

public boolean forEachPair(IntObjectProcedure procedure)

Applies a procedure to each (key,value) pair of the receiver, if any. Iteration order is guaranteed to be identical to the order used by method forEachKey(IntProcedure).

Parameters:

procedure - the procedure to be applied. Stops iteration if the procedure returns false, otherwise continues.

Returns:

false if the procedure stopped before all keys where iterated over, true otherwise.

get

public abstract Object get(int key)

Returns the value associated with the specified key. It is often a good idea to first check with containsKey(int) whether the given key has a value associated or not, i.e. whether there exists an association for the given key or not.

Parameters:

key - the key to be searched for.

Returns:

the value associated with the specified key; null if no such key is present.

keyOf

public int keyOf(Object value)

Returns the first key the given value is associated with. It is often a good idea to first check with containsValue(Object) whether there exists an association from a key to this value. Search order is guaranteed to be identical to the order used by method forEachKey(IntProcedure).

Parameters:

value - the value to search for.

Returns:

the first key for which holds get(key) == value; returns Integer.MIN_VALUE if no such key exists.

keys

public IntArrayList keys()

Returns a list filled with all keys contained in the receiver. The returned list has a size that equals this.size(). Iteration order is guaranteed to be identical to the order used by method forEachKey(IntProcedure).

This method can be used to iterate over the keys of the receiver.

Returns:

the keys.

keys

public void keys(IntArrayList list)

Fills all keys contained in the receiver into the specified list. Fills the list, starting at index 0. After this call returns the specified list has a new size that equals this.size(). Iteration order is guaranteed to be identical to the order used by method forEachKey(IntProcedure).

This method can be used to iterate over the keys of the receiver.

Parameters:

list - the list to be filled, can have any size.

keysSortedByValue

public void keysSortedByValue(IntArrayList keyList)

Fills all keys sorted ascending by their associated value into the specified list. Fills into the list, starting at index 0. After this call returns the specified list has a new size that equals this.size(). Primary sort criterium is "value", secondary sort criterium is "key". This means that if any two values are equal, the smaller key comes first.

Example:
keys = (8,7,6), values = (1,2,2) --> keyList = (8,6,7)

Parameters:

keyList - the list to be filled, can have any size.

pairsMatching

public void pairsMatching(IntObjectProcedure condition,
                          IntArrayList keyList,
                          ObjectArrayList valueList)

Fills all pairs satisfying a given condition into the specified lists. Fills into the lists, starting at index 0. After this call returns the specified lists both have a new size, the number of pairs satisfying the condition. Iteration order is guaranteed to be identical to the order used by method forEachKey(IntProcedure).

Example:

IntObjectProcedure condition = new IntObjectProcedure() { // match even keys only
        public boolean apply(int key, Object value) { return key%2==0; }
}
keys = (8,7,6), values = (1,2,2) --> keyList = (6,8), valueList = (2,1)

Parameters:

condition - the condition to be matched. Takes the current key as first and the current value as second argument.

keyList - the list to be filled with keys, can have any size.

valueList - the list to be filled with values, can have any size.

pairsSortedByKey

public void pairsSortedByKey(IntArrayList keyList,
                             ObjectArrayList valueList)

Fills all keys and values sorted ascending by key into the specified lists. Fills into the lists, starting at index 0. After this call returns the specified lists both have a new size that equals this.size().

Example:
keys = (8,7,6), values = (1,2,2) --> keyList = (6,7,8), valueList = (2,2,1)

Parameters:

keyList - the list to be filled with keys, can have any size.

valueList - the list to be filled with values, can have any size.

pairsSortedByValue

public void pairsSortedByValue(IntArrayList keyList,
                               ObjectArrayList valueList)

Fills all keys and values sorted ascending by value according to natural ordering into the specified lists. Fills into the lists, starting at index 0. After this call returns the specified lists both have a new size that equals this.size(). Primary sort criterium is "value", secondary sort criterium is "key". This means that if any two values are equal, the smaller key comes first.

Example:
keys = (8,7,6), values = (1,2,2) --> keyList = (8,6,7), valueList = (1,2,2)

Parameters:

keyList - the list to be filled with keys, can have any size.

valueList - the list to be filled with values, can have any size.

put

public abstract boolean put(int key,
                            Object value)

Associates the given key with the given value. Replaces any old (key,someOtherValue) association, if existing.

Parameters:

key - the key the value shall be associated with.

value - the value to be associated.

Returns:

true if the receiver did not already contain such a key; false if the receiver did already contain such a key - the new value has now replaced the formerly associated value.

removeKey

public abstract boolean removeKey(int key)

Removes the given key with its associated element from the receiver, if present.

Parameters:

key - the key to be removed from the receiver.

Returns:

true if the receiver contained the specified key, false otherwise.

toString

public String toString()

Returns a string representation of the receiver, containing the String representation of each key-value pair, sorted ascending by key.

toStringByValue

public String toStringByValue()

Returns a string representation of the receiver, containing the String representation of each key-value pair, sorted ascending by value, according to natural ordering.

values

public ObjectArrayList values()

Returns a list filled with all values contained in the receiver. The returned list has a size that equals this.size(). Iteration order is guaranteed to be identical to the order used by method forEachKey(IntProcedure).

This method can be used to iterate over the values of the receiver.

Returns:

the values.

values

public void values(ObjectArrayList list)

Fills all values contained in the receiver into the specified list. Fills the list, starting at index 0. After this call returns the specified list has a new size that equals this.size(). Iteration order is guaranteed to be identical to the order used by method forEachKey(IntProcedure).

This method can be used to iterate over the values of the receiver.

Parameters:

list - the list to be filled, can have any size.