ix.util.lisp
Class Interpreter.LexicalEnv

java.lang.Object
  ix.util.lisp.Interpreter.AbstractEnv
      ix.util.lisp.Interpreter.LexicalEnv

All Implemented Interfaces:

Interpreter.Env

Enclosing class:

Interpreter

public class Interpreter.LexicalEnv
extends Interpreter.AbstractEnv

An environment for local values of variables.

Field Summary

(package private) Interpreter.LexicalEnv	enclosingEnv
(package private) java.lang.Object[]	vals
(package private) Symbol[]	vars

Constructor Summary

Interpreter.LexicalEnv(Symbol[] vars, java.lang.Object[] vals, Interpreter.LexicalEnv next)

Method Summary

java.lang.Object	assign(Interpreter.VarRef ref, java.lang.Object val) Changes the value bound to the variable and then returns the new value.
Interpreter.Env	bind(Symbol[] vars, java.lang.Object[] vals) Returns a new Env in which the variables are bound to the corresponding values.
protected int	findIndex(Symbol var)
protected void	findOffsets(Interpreter.VarRef ref)
java.lang.Object	lookup(Interpreter.VarRef ref) Returns the value bound to the variable by this environment.

Methods inherited from class ix.util.lisp.Interpreter.AbstractEnv

defaultValue, isTrue

Methods inherited from class java.lang.Object

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

Field Detail

vars

Symbol[] vars

vals

java.lang.Object[] vals

enclosingEnv

Interpreter.LexicalEnv enclosingEnv

Constructor Detail

Interpreter.LexicalEnv

public Interpreter.LexicalEnv(Symbol[] vars,
                              java.lang.Object[] vals,
                              Interpreter.LexicalEnv next)

Method Detail

lookup

public java.lang.Object lookup(Interpreter.VarRef ref)

Description copied from interface: Interpreter.Env

Returns the value bound to the variable by this environment.

bind

public Interpreter.Env bind(Symbol[] vars,
                            java.lang.Object[] vals)

Description copied from interface: Interpreter.Env

Returns a new Env in which the variables are bound to the corresponding values.

assign

public java.lang.Object assign(Interpreter.VarRef ref,
                               java.lang.Object val)

Description copied from interface: Interpreter.Env

Changes the value bound to the variable and then returns the new value. Note that this typically modifies an existing binding relationship rather than create a new one; however, a new one may be created, for instance if the variable is not already bound.

findOffsets

protected void findOffsets(Interpreter.VarRef ref)

findIndex

protected int findIndex(Symbol var)