EvalContext.java 

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package blog;

import java.util.*;
import java.io.PrintStream;
Interface for objects that encapsulate a partial world and an assignment of values to logical variables. To facilitate debugging, an EvalContext object also maintains a separate stack of objects being evaluated. 


public interface EvalContext {
Returns the value of the given basic random variable in this partial world, or null if the given variable is not instantiated. 


    Object getValue(BasicVar var);
Returns the set of objects that satisfy the given POP in this world. The objects may be represented as actual objects or identifiers, depending on the way the underlying PartialWorld implementation handles objects of the relevant type. A null return value indicates that the relevant number variable is not instantiated.

The set returned by this method will remain correct if new basic random variables are instantiated. It may not remain correct if new identifiers are added or already-instantiated random variables are changed. 


    ObjectSet getSatisfiers(NumberVar popApp);
Returns the NumberVar (i.e., POP and generating objects) such that the given object satisfies that POP applied to those generating objects in this world. Returns null if the given object does not satisfy any POP application. in this world

Throws:  IllegalArgumentException if the given object does not exist 


    NumberVar getPOPAppSatisfied(Object obj);
Returns true if the world that underlies this context uses object identifiers for the given type. 


    boolean usesIdentifiers(Type type);
Returns Boolean.TRUE if obj exists in all worlds consistent with this context's partial world. This is true if obj is a guaranteed object, a concrete non-guaranteed object whose number variable is instantiated to a sufficiently large value, or an object identifier. Returns Boolean.FALSE if obj is a concrete non-guaranteed object whose number variable is instantiated to a value that is too small. If neither of the above cases holds, then this method returns null. that is not in the common ground of this context's world

Throws:  IllegalArgumentException if obj is an identifier 


    Boolean objectExists(Object obj);
Returns the value of the given logical variable in this context, or null if the given logical variable has no assigned value. 


    Object getLogicalVarValue(LogicalVar var);
Returns the set of objects that are the value of some logical variable in this context.

Returns:  unmodifiable Set of Object 


    Set getLogicalVarValues();
Returns a string describing the assignment of values to variables in this context. 


    String getAssignmentStr();
Assigns the given value to the given logical variable, overwriting any previous value. 


    void assign(LogicalVar var, Object value);
Assigns values to a tuple of logical variables. the elements of vars, representing values for those variables

Throws:  IllegalStateException if the assignment stack is empty
Parameters: 
vars - array of LogicalVar objects
values - array of Objects, in one-to-one correspondence with


    void assignTuple(LogicalVar[] vars, Object[] values);
Erases any value currently assigned to the given logical variable. 


    void unassign(LogicalVar var);
Erases any values currently assigned to any of the given logical variables. 


    void unassignTuple(LogicalVar[] vars);
Pushes the given object onto the stack of objects being evaluated. This stack is maintained purely so that the EvalContext can print more informative error messages. 


    void pushEvaluee(Object evaluee);
Pops the top object from the stack of objects being evaluated. is empty

Throws:  IllegalStateException if the stack of objects being evaluated 


    void popEvaluee();
Prints the sequence of objects being evaluated, in the order they were added to the stack, to the given stream. 


    void printEvalTrace(PrintStream s);
}

This file was generated on Tue Jun 08 17:53:36 PDT 2010 from file EvalContext.java
by the ilog.language.tools.Hilite Java tool written by Hassan Aït-Kaci