Class MapUtil

java.lang.Object

com.ibm.wala.util.collections.MapUtil

public class MapUtil
extends Object

utilities for managing Maps

Constructor Summary

Constructors

Constructor	Description
MapUtil()

Method Summary

Modifier and Type	Method	Description
static <K, T> Collection<T>	findOrCreateCollection(Map<K,Collection<T>> M, K key)
static <K, T> List<T>	findOrCreateList(Map<K,List<T>> M, K key)
static <K, K2, V> Map<K2,V>	findOrCreateMap(Map<K,Map<K2,V>> M, K key)
static <K> MutableIntSet	findOrCreateMutableIntSet(Map<K,MutableIntSet> M, K key)
static <K, T> Set<T>	findOrCreateSet(Map<K,Set<T>> M, K key)
static <K, V> V	findOrCreateValue(Map<K,V> M, K key, Factory<V> factory)
static <K, V> WeakHashMap<K,V>	findOrCreateWeakHashMap(Map<Object,WeakHashMap<K,V>> M, Object key)
static <K, V> Map<Set<K>,V>	groupKeysByValue(Map<K,V> m)
static <K, V> Map<V,Set<K>>	inverseMap(Map<K,Set<V>> m)
static <K, V> Map<V,K>	invertOneToOneMap(Map<K,V> m)	invert an input map that is one-to-one (i.e., it does not map two different keys to the same value)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

MapUtil

public MapUtil()

Method Details

findOrCreateSet

public static <K,
T> Set<T> findOrCreateSet(Map<K,Set<T>> M,
 K key)

Parameters:

M - a mapping from Object -> Set

Returns:

the Set corresponding to key in M; create one if needed

Throws:

IllegalArgumentException - if M is null

ClassCastException - if the key is of an inappropriate type for this map (optional)

NullPointerException - if the specified key is null and this map does not permit null keys (optional)

findOrCreateMutableIntSet

public static <K> MutableIntSet findOrCreateMutableIntSet(Map<K,MutableIntSet> M,
 K key)

Throws:

ClassCastException - if the key is of an inappropriate type for this map (optional)

NullPointerException - if the specified key is null and this map does not permit null keys (optional)

findOrCreateCollection

public static <K,
T> Collection<T> findOrCreateCollection(Map<K,Collection<T>> M,
 K key)

Returns:

the Collection corresponding to key in M; create one if needed

Throws:

ClassCastException - if the key is of an inappropriate type for this map (optional)

NullPointerException - if the specified key is null and this map does not permit null keys (optional)

findOrCreateList

public static <K,
T> List<T> findOrCreateList(Map<K,List<T>> M,
 K key)

Returns:

the Set corresponding to key in M; create one if needed

Throws:

IllegalArgumentException - if M is null

ClassCastException - if the key is of an inappropriate type for this map (optional)

NullPointerException - if the specified key is null and this map does not permit null keys (optional)

findOrCreateMap

public static <K,
K2,
V> Map<K2,V> findOrCreateMap(Map<K,Map<K2,V>> M,
 K key)

Parameters:

M - a mapping from Object -> Map

Returns:

the Map corresponding to key in M; create one if needed

Throws:

IllegalArgumentException - if M is null

ClassCastException - if the key is of an inappropriate type for this map (optional)

NullPointerException - if the specified key is null and this map does not permit null keys (optional)

findOrCreateValue

public static <K,
V> V findOrCreateValue(Map<K,V> M,
 K key,
 Factory<V> factory)

Throws:

ClassCastException - if the key is of an inappropriate type for this map (optional)

NullPointerException - if the specified key is null and this map does not permit null keys (optional)

findOrCreateWeakHashMap

public static <K,
V> WeakHashMap<K,V> findOrCreateWeakHashMap(Map<Object,WeakHashMap<K,V>> M,
 Object key)

Parameters:

M - a mapping from Object -> WeakHashMap

Returns:

the WeakHashMap corresponding to key in M; create one if needed

Throws:

IllegalArgumentException - if M is null

ClassCastException - if the key is of an inappropriate type for this map (optional)

NullPointerException - if the specified key is null and this map does not permit null keys (optional)

inverseMap

public static <K,
V> Map<V,Set<K>> inverseMap(Map<K,Set<V>> m)

Parameters:

m - a map from key -> Set<value>

Returns:

inverted map, value -> Set<key>

Throws:

IllegalArgumentException - if m is null

invertOneToOneMap

public static <K,
V> Map<V,K> invertOneToOneMap(Map<K,V> m)

invert an input map that is one-to-one (i.e., it does not map two different keys to the same value)

Throws:

IllegalArgumentException - if m is null

IllegalArgumentException - if m is not one-to-one

groupKeysByValue

public static <K,
V> Map<Set<K>,V> groupKeysByValue(Map<K,V> m)