Direct Known Subclasses:

ClassMemberLocation, ConstrainedLocation, IndirectableLocation, ProcLocation, PropertyLocation

public abstract class Location<T>
extends java.lang.Object

• Field Summary

  Fields

  Modifier and Type	Field and Description
  static java.lang.String	UNBOUND Magic value used to indicate there is no property binding.

• Constructor Summary

  Constructors

  Constructor and Description
  Location ()

• Method Summary

  All Methods

  Modifier and Type	Method and Description
  static Location	define (Symbol name) Implement top-level 'define' for Scheme in interactive mode.
  boolean	entered () True if directly entered in an Environment.
  abstract T	get () Get the current value of this location.
  T	get (T defaultValue)
  Location	getBase ()
  java.lang.Object	getKeyProperty ()
  Symbol	getKeySymbol ()
  T	getValue ()
  abstract boolean	isBound ()
  boolean	isConstant ()
  static Location	make (java.lang.Object init, java.lang.String name)
  static IndirectableLocation	make (java.lang.String name)
  static IndirectableLocation	make (Symbol name)
  void	print (java.io.PrintWriter ps)
  abstract void	set (T value)
  void	setRestore (java.lang.Object oldValue) Restore an old value.
  T	setValue (T newValue)
  java.lang.Object	setWithSave (T newValue) Set a value, but return cookie so old value can be restored.
  java.lang.String	toString ()
  void	undefine ()

  • Methods inherited from class java.lang.Object

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

• Field Detail

  • UNBOUND

    public static final java.lang.String UNBOUND

    Magic value used to indicate there is no property binding.

• Constructor Detail

  • Location

    public Location()

• Method Detail

  • getKeySymbol

    public Symbol getKeySymbol()

  • getKeyProperty

    public java.lang.Object getKeyProperty()

  • toString

    public java.lang.String toString()

    Overrides:

    toString in class java.lang.Object

  • get

    public T get(T defaultValue)

  • get

    public abstract T get()

    Get the current value of this location.

    Throws:

    UnboundLocationException - the location does not have a value.

  • set

    public abstract void set(T value)

  • undefine

    public void undefine()

  • setWithSave

    public java.lang.Object setWithSave(T newValue)

    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.

  • setRestore

    public void setRestore(java.lang.Object oldValue)

    Restore an old value.

    Parameters:

    oldValue - the return value from a prior setWithSave.

  • isBound

    public abstract boolean isBound()

  • isConstant

    public boolean isConstant()

  • getBase

    public Location getBase()

  • getValue

    public final T getValue()

  • setValue

    public final T setValue(T newValue)

  • entered

    public boolean entered()

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

  • print

    public void print(java.io.PrintWriter ps)

  • make

    public static Location make(java.lang.Object init,
     java.lang.String name)

  • make

    public static IndirectableLocation make(java.lang.String name)

  • make

    public static IndirectableLocation make(Symbol name)

  • define

    public static Location define(Symbol name)

    Implement top-level 'define' for Scheme in interactive mode. I.e. if there is no binding, create it; if the existing binding is non-constant, set its value; if it is constant, create a new binding initialized to the old value (though we actually change the binding to non-constant).