Class ScopedMap<K,V>

java.lang.Object
  ScopedMap<K,V>

public class ScopedMap<K,V>
extends java.lang.Object

A ScopedMap is similar to a Map, but with nested scopes.

Constructor Summary

ScopedMap()
makes a ScopedMap that maps no keys to values and is set to the global scope (nesting level 0)

Method Summary

void	enterScope() sets the ScopedMap to a new scope nested inside the previous one; the nesting level increases by one
void	exitScope() exits from the current scope back to the containing one; the nesting level, which must have been positive, decreases by one
V	get(K key) gets the value corresponding to the key, at the innermost scope for which there is one; if there is none, returns null
int	getNestingLevel() returns the current nesting level
boolean	isLocal(K key) returns true if the key has a value at the current scope (ignoring surrounding ones)
void	put(K key, V value) puts the key/value pair in at the current scope; if the key is already in at the current nesting level, the new value replaces the old one; neither the key nor the value may be null

Methods inherited from class java.lang.Object

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

Constructor Detail

ScopedMap

public ScopedMap()

makes a ScopedMap that maps no keys to values and is set to the global scope (nesting level 0)

Method Detail

enterScope

public void enterScope()

sets the ScopedMap to a new scope nested inside the previous one; the nesting level increases by one

exitScope

public void exitScope()

exits from the current scope back to the containing one; the nesting level, which must have been positive, decreases by one

put

public void put(K key,
                V value)

puts the key/value pair in at the current scope; if the key is already in at the current nesting level, the new value replaces the old one; neither the key nor the value may be null

get

public V get(K key)

gets the value corresponding to the key, at the innermost scope for which there is one; if there is none, returns null

isLocal

public boolean isLocal(K key)

returns true if the key has a value at the current scope (ignoring surrounding ones)

getNestingLevel

public int getNestingLevel()

returns the current nesting level