package gve.calc.formula;
import java.awt.*; 

public class OperatorPow extends InfixBinaryOp {
	public String getName() { return "^"; }
	public int getPri() { return 2000; }

	public OperatorPow(Part l,Part r) {
		super(l,r);
	}

	
 if r in N (integer) and r != 0, use this method 
	private Interval evalN(Interval l,double r) {
		if (r == 1) return new Interval(l.low,l.high,l.openLow,l.openHigh);
		double pow1 = Math.pow(l.low,r);
		double pow2 = Math.pow(l.high,r);
		if ( (((long)r)%2) == 0) {	// even: x^2, x^4, ...
			if (l.low<0 && 0<l.high) // l has 0 inside it
				if (pow1 > pow2) return new Interval(0,pow1,false,l.openLow);
				else return new Interval(0,pow2,false,l.openHigh);
			else if (l.high < 0)	// l negative
				return new Interval(pow2,pow1,l.openHigh,l.openLow);
			else	// l positive
				return new Interval(pow1,pow2,l.openLow,l.openHigh);
		} else {	//odd: ...^3, ...^5, ...^7
			return new Interval(pow1,pow2,l.openLow,l.openHigh);
		}
	}

	public Part evaluate(Evaluator ev) {
		Part l = left.evaluate(ev);
		Part r = right.evaluate(ev);

		if (l instanceof Real && r instanceof Real) {
			try {
				return new Real(Math.pow(((Real)l).doubleValue,((Real)r).doubleValue));
			} catch (ArithmeticException exc) {}
		} else if (l instanceof Interval && r instanceof Real) {
			double pow = ((Real)r).doubleValue;
			if (pow == 0) return new Real(0);
			Interval lef = (Interval)l;
			if (pow == 1) return new Interval(lef.low,lef.high,lef.openLow,lef.openHigh);
			if (pow == (long)pow) {	// r is integer
				if (pow > 0) return evalN(lef,pow);
				if (pow < 0) return new Fraction(new Real(1),evalN(lef,-pow)).evaluate(ev);
			}
		}
		return new OperatorPow(l,r);
	}

	public Component createView(FormulaView view) {
		return new OperatorPowView(this,view);
	}
}