org.luaj.vm2
Class WeakTable

java.lang.Object
  org.luaj.vm2.WeakTable

public class WeakTable
extends java.lang.Object

Subclass of LuaTable that provides weak key and weak value semantics.

Normally these are not created directly, but indirectly when changing the mode of a LuaTable as lua script executes.

However, calling the constructors directly when weak tables are required from Java will reduce overhead.

Nested Class Summary

static class

WeakTable.WeakSlot

Constructor Summary

WeakTable(boolean weakkeys, boolean weakvalues, LuaValue backing)
Construct a table with weak keys, weak values, or both

Method Summary

LuaValue	arrayget(LuaValue[] array, int index) Returns the value at the given index in the array, or null if it is a weak reference that has been dropped.
org.luaj.vm2.LuaTable.Slot	entry(LuaValue key, LuaValue value) Return an instance of Slot appropriate for the given key and value.
static LuaTable	make(boolean weakkeys, boolean weakvalues)
protected static LuaValue	strengthen(java.lang.Object ref) Unwrap a LuaValue from a WeakReference and/or WeakUserdata.
LuaValue	toLuaValue() Return this metatable as a LuaValue.
boolean	useWeakKeys() Return whether or not this table's keys are weak.
boolean	useWeakValues() Return whether or not this table's values are weak.
protected static LuaValue	weaken(LuaValue value) Self-sent message to convert a value to its weak counterpart
LuaValue	wrap(LuaValue value) Returns the given value wrapped in a weak reference if appropriate.

Methods inherited from class java.lang.Object

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

Constructor Detail

WeakTable

public WeakTable(boolean weakkeys,
                 boolean weakvalues,
                 LuaValue backing)

Construct a table with weak keys, weak values, or both

Parameters:

weakkeys - true to let the table have weak keys

weakvalues - true to let the table have weak values

Method Detail

make

public static LuaTable make(boolean weakkeys,
                            boolean weakvalues)

useWeakKeys

public boolean useWeakKeys()

Return whether or not this table's keys are weak.

useWeakValues

public boolean useWeakValues()

Return whether or not this table's values are weak.

toLuaValue

public LuaValue toLuaValue()

Return this metatable as a LuaValue.

entry

public org.luaj.vm2.LuaTable.Slot entry(LuaValue key,
                                        LuaValue value)

Return an instance of Slot appropriate for the given key and value.

weaken

protected static LuaValue weaken(LuaValue value)

Self-sent message to convert a value to its weak counterpart

Parameters:

value - value to convert

Returns:

LuaValue that is a strong or weak reference, depending on type of value

strengthen

protected static LuaValue strengthen(java.lang.Object ref)

Unwrap a LuaValue from a WeakReference and/or WeakUserdata.

Parameters:

ref - reference to convert

Returns:

LuaValue or null

See Also:

weaken(LuaValue)

wrap

public LuaValue wrap(LuaValue value)

Returns the given value wrapped in a weak reference if appropriate.

arrayget

public LuaValue arrayget(LuaValue[] array,
                         int index)

Returns the value at the given index in the array, or null if it is a weak reference that has been dropped.