gnu.mapping

Class Location

public abstract class Location extends Object

A Location is an abstract cell/location/variable with a value.

Field Summary
static String	UNBOUND Magic value used to indicate there is no property binding.

Constructor Summary
	Location()

Method Summary
boolean	entered() True if directly entered in an Environment.
abstract Object	get(Object defaultValue)
Object	get() Get the current value of this location.
Location	getBase()
Object	getKeyProperty()
Symbol	getKeySymbol()
Object	getValue()
boolean	isBound()
boolean	isConstant()
static Location	make(Object init, String name)
static IndirectableLocation	make(String name)
static IndirectableLocation	make(Symbol name)
void	print(PrintWriter ps)
abstract void	set(Object value)
void	setRestore(Object oldValue, CallContext ctx) Restore an old value.
Object	setValue(Object newValue)
Object	setWithSave(Object newValue, CallContext ctx) Set a value, but return cookie so old value can be restored.
String	toString()
void	undefine()

Field Detail

UNBOUND

public static final String UNBOUND

Magic value used to indicate there is no property binding.

Constructor Detail

Location

public Location()

Method Detail

entered

public boolean entered()

True if directly entered in an Environment. (Only if NamedLocation.)

get

public abstract Object get(Object defaultValue)

get

public final Object get()

Get the current value of this location.

Throws: UnboundLocationException the location does not have a value.

getBase

public Location getBase()

getKeyProperty

public Object getKeyProperty()

getKeySymbol

public Symbol getKeySymbol()

getValue

public final Object getValue()

isBound

public boolean isBound()

isConstant

public boolean isConstant()

make

public static Location make(Object init, String name)

make

public static IndirectableLocation make(String name)

make

public static IndirectableLocation make(Symbol name)

print

public void print(PrintWriter ps)

set

public abstract void set(Object value)

setRestore

public void setRestore(Object oldValue, CallContext ctx)

Restore an old value.

Parameters: oldValue the return value from a prior setWithSave.

setValue

public final Object setValue(Object newValue)

setWithSave

public Object setWithSave(Object newValue, CallContext ctx)

Set a value, but return cookie so old value can be restored. This is intended for fluid-let where (in the case of multiple threads) a simple save-restore isn't always the right thing.

toString

public String toString()

undefine

public void undefine()