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/*
* Modification History
*
* 2003-May-2 Jason Rohrer
* Created.
*
* 2003-May-3 Jason Rohrer
* Fixed a few compile-time errors.
*/
#ifndef BINARY_LOGIC_EXPRESSION_INCLUDED
#define BINARY_LOGIC_EXPRESSION_INCLUDED
#include "Expression.h"
#include "BinaryOperationExpression.h"
/**
* Expression implementation of a binary logic operation.
*
* Evaluating this expression returns 1 if the logic operation is true
* and 0 if it is false.
*
* During evaluation, positive values are treated as logical true,
* while all other values (zero and negative) are treated as false.
*
* @author Jason Rohrer
*/
class BinaryLogicExpression : public BinaryOperationExpression {
public:
static const int LOGIC_AND = 0;
static const int LOGIC_OR = 1;
static const int LOGIC_XOR = 2;
/**
* Constructs a binary logic operation expression.
*
* Both arguments are destroyed when the class is destroyed.
*
* @param inLogicOperation the logical operation, one of
* LOGIC_AND, LOGIC_OR, LOGIC_XOR.
* @param inArgumentA the first argument.
* @param inArgumentB the second argument.
*/
BinaryLogicExpression( int inLogicOperation,
Expression *inArgumentA,
Expression *inArgumentB );
/**
* Gets the logical operation.
*
* @return one of LOGIC_AND, LOGIC_OR, LOGIC_XOR.
*/
int getLogicOperation();
/**
* Sets the logical operation
*
* @param inLogicOperation LOGIC_AND, LOGIC_OR, LOGIC_XOR.
*/
void setLogicOperation( int inLogicOperation );
/**
* A static version of getID().
*/
static long staticGetID();
// implements the Expression interface
virtual double evaluate();
virtual long getID();
virtual void print();
virtual Expression *copy();
protected:
static long mID;
int mLogicOperation;
};
// static init
long BinaryLogicExpression::mID = 16;
inline BinaryLogicExpression::BinaryLogicExpression(
int inLogicOperation,
Expression *inArgumentA,
Expression *inArgumentB )
: BinaryOperationExpression( inArgumentA, inArgumentB ),
mLogicOperation( inLogicOperation ) {
}
inline int BinaryLogicExpression::getLogicOperation() {
return mLogicOperation;
}
inline void BinaryLogicExpression::setLogicOperation( int inLogicOperation ) {
mLogicOperation = inLogicOperation;
}
inline double BinaryLogicExpression::evaluate() {
if( mLogicOperation == LOGIC_AND ) {
if( mArgumentA->evaluate() > 0 && mArgumentB->evaluate() > 0 ) {
return 1;
}
else {
return 0;
}
}
else if( mLogicOperation == LOGIC_OR ) {
if( mArgumentA->evaluate() > 0 || mArgumentB->evaluate() > 0 ) {
return 1;
}
else {
return 0;
}
}
else if( mLogicOperation == LOGIC_XOR ) {
double valA = mArgumentA->evaluate();
double valB = mArgumentB->evaluate();
if( ( valA > 0 && valB <= 0 ) || ( valA <= 0 && valB > 0 ) ) {
return 1;
}
else {
return 0;
}
}
else {
// unknown operation type
// default to false
return 0;
}
}
inline long BinaryLogicExpression::getID() {
return mID;
}
inline long BinaryLogicExpression::staticGetID() {
return mID;
}
inline void BinaryLogicExpression::print() {
printf( "( " );
mArgumentA->print();
if( mLogicOperation == LOGIC_AND ) {
printf( " and " );
}
else if( mLogicOperation == LOGIC_OR ) {
printf( " or " );
}
else if( mLogicOperation == LOGIC_XOR ) {
printf( " xor " );
}
else {
printf( " UNKNOWN_LOGIC_OPERATION " );
}
mArgumentB->print();
printf( " )" );
}
inline Expression *BinaryLogicExpression::copy() {
BinaryLogicExpression *copy =
new BinaryLogicExpression( mLogicOperation,
mArgumentA->copy(),
mArgumentB->copy() );
return copy;
}
#endif
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