org.openl.ie.constrainer.IntExp Maven / Gradle / Ivy
Show all versions of org.openl.rules.constrainer Show documentation
package org.openl.ie.constrainer;
///////////////////////////////////////////////////////////////////////////////
/*
* Copyright Exigen Group 1998, 1999, 2000
* 320 Amboy Ave., Metuchen, NJ, 08840, USA, www.exigengroup.com
*
* The copyright to the computer program(s) herein
* is the property of Exigen Group, USA. All rights reserved.
* The program(s) may be used and/or copied only with
* the written permission of Exigen Group
* or in accordance with the terms and conditions
* stipulated in the agreement/contract under which
* the program(s) have been supplied.
*/
///////////////////////////////////////////////////////////////////////////////
//
//: IntExp.java
//
/**
* An interface for the constrained integer expression. Any arithmetic operation where the operands are the integer
* variables/expressions returns the integer expression.
*/
public interface IntExp extends Expression {
/**
* An interface used in the iteration of the domain of the integer expression.
*
* @see #iterateDomain
*/
interface IntDomainIterator {
/**
* Processes each value contained within domain one by one (by convention from lowest to highest value).
*
* It should return false to stop iteration or true to continue.
*
* @see IntExp#iterateDomain
*/
boolean doSomethingOrStop(int val) throws Failure;
}
/**
* The minimum value of the int type. Note that MIN_VALUE == -MAX_VALUE is not true for
* java.lang.Integer.
*/
int MIN_VALUE = -Integer.MAX_VALUE;
/**
* The largest value of type int.
*/
int MAX_VALUE = Integer.MAX_VALUE;
/**
* Returns the expression: (this + value).
*/
IntExp add(int value);
/**
* Returns the expression: (this + exp).
*/
IntExp add(IntExp exp);
/**
* Returns true if this expression is bound. An expression is considered bound if contains only one value in its
* domain.
*
* @return true if this expression is bound: it's domain has only one value.
*/
boolean bound();
/**
* Returns true if the domain of this expression contains the value.
*
* NOTE: in some cases it is not possible (or feasible) to calculate contains with 100% accuracy.
* We also cannot guarantee a consistency between contains and size method for all
* expressions. In other words if contains(value) returns true it might happen that value
* does not belong to the expression's domain. The opposite (false) is always true :).
*
* @return true if the expression contains the value in it's domain.
*/
boolean contains(int value);
/**
* Returns the display string for the current domain of this expression.
*/
String domainToString();
/**
* Returns the boolean expression: (this == value).
*/
IntBoolExp eq(int value);
/**
* Returns the constraint: (this == value).
*/
Constraint equals(int value);
/**
* Returns the boolean expression: (this >= value).
*/
IntBoolExp ge(int value);
/**
* Returns the boolean expression: (this > value).
*/
IntBoolExp gt(int value);
/**
* Returns the boolean expression: (this > exp).
*/
IntBoolExp gt(IntExp exp);
/**
* Iterates the domain of this expression by calling doSomethingOrStop(int val) of
* IntDomainIterator.
*
* @see IntDomainIterator
* @see IntDomainIterator#doSomethingOrStop
*/
void iterateDomain(IntDomainIterator it) throws Failure;
/**
* Returns the boolean expression: (this <= value).
*/
IntBoolExp le(int value);
/**
* Returns the boolean expression: (this < value).
*/
IntBoolExp lt(int value);
/**
* Returns the boolean expression: (this < exp).
*/
IntBoolExp lt(IntExp exp);
/**
* Returns the largest value of the domain of this expression.
*/
int max();
/**
* Returns the smallest value of the domain of this expression.
*/
int min();
/**
* Removes the range [min..max] from the domain of this expression.
*
* @param min range minimum value.
* @param max range maxinum value.
* @throws Failure if domain becomes empty.
*/
void removeRange(int min, int max) throws Failure;
/**
* Removes the value from the domain of this expression.
*
* @throws Failure if domain becomes empty.
*/
void removeValue(int value) throws Failure;
/**
* Sets the maximum value for this expression.
*
* @param max new maximum value.
* @throws Failure if domain becomes empty.
*/
void setMax(int max) throws Failure;
/**
* Sets the minimum value for this expression.
*
* @param min new miminum value.
* @throws Failure if domain becomes empty.
*/
void setMin(int min) throws Failure;
/**
* Bounds this variable to be equal to the value.
*
* @param value a value to be set.
* @throws Failure when: !this.contains(value).
* @see #bound
*/
void setValue(int value) throws Failure;
/**
* Returns the size (cardinality) of the domain of this expression. The domain's size is the number of integer
* values the domain.
*
* @return the number of values in the domain of this variable.
*/
int size();
/**
* Returns the value this expression if it is bound.
*
* @return the value of this expresion.
* @throws Failure if this expresionis not bound.
* @see #bound
*/
int value() throws Failure;
/**
* @return value without checking bound(); should be called only after the caller checked the bounds already
*/
int valueUnsafe();
} // ~IntExp