NTPrimitivePower.java

/*******************************************************************************
 * Copyright (c) 2013 Stephen F. Siegel, University of Delaware.
 * 
 * This file is part of SARL.
 * 
 * SARL is free software: you can redistribute it and/or modify it under the
 * terms of the GNU Lesser General Public License as published by the Free
 * Software Foundation, either version 3 of the License, or (at your option) any
 * later version.
 * 
 * SARL is distributed in the hope that it will be useful, but WITHOUT ANY
 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
 * A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
 * details.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with SARL. If not, see <http://www.gnu.org/licenses/>.
 ******************************************************************************/
package edu.udel.cis.vsl.sarl.ideal.common;

import edu.udel.cis.vsl.sarl.IF.object.IntObject;
import edu.udel.cis.vsl.sarl.collections.IF.SymbolicMap;
import edu.udel.cis.vsl.sarl.ideal.IF.Constant;
import edu.udel.cis.vsl.sarl.ideal.IF.IdealFactory;
import edu.udel.cis.vsl.sarl.ideal.IF.Monic;
import edu.udel.cis.vsl.sarl.ideal.IF.Monomial;
import edu.udel.cis.vsl.sarl.ideal.IF.Polynomial;
import edu.udel.cis.vsl.sarl.ideal.IF.Primitive;
import edu.udel.cis.vsl.sarl.ideal.IF.PrimitivePower;

/**
 * A non-trivial primitive power represents a Primitive expression raised to
 * some concrete integer exponent; the exponent is at least 2.
 * 
 * @author siegel
 * 
 */
public class NTPrimitivePower extends IdealExpression implements PrimitivePower {

	protected NTPrimitivePower(Primitive primitive, IntObject exponent) {
		super(SymbolicOperator.POWER, primitive.type(), primitive, exponent);
		assert exponent.getInt() >= 2;
	}

	public NumericPrimitive primitive() {
		return (NumericPrimitive) argument(0);
	}

	@Override
	public SymbolicMap<NumericPrimitive, PrimitivePower> monicFactors(
			IdealFactory factory) {
		return factory.singletonMap(primitive(), (PrimitivePower) this);
	}

	@Override
	public Constant monomialConstant(IdealFactory factory) {
		return factory.one(type());
	}

	@Override
	public Monic monic(IdealFactory factory) {
		return this;
	}

	@Override
	public SymbolicMap<Monic, Monomial> termMap(IdealFactory factory) {
		return factory.singletonMap((Monic) this, (Monomial) this);
	}

	@Override
	public IntObject primitivePowerExponent(IdealFactory factory) {
		return exponent();
	}

	public IntObject exponent() {
		return (IntObject) argument(1);
	}

	@Override
	public Monomial factorization(IdealFactory factory) {
		return this;
	}

	@Override
	public Polynomial numerator(IdealFactory factory) {
		return this;
	}

	@Override
	public Polynomial denominator(IdealFactory factory) {
		return factory.one(type());
	}

	@Override
	public Monomial leadingTerm() {
		return this;
	}

	@Override
	public NumericPrimitive primitive(IdealFactory factory) {
		return (NumericPrimitive) argument(0);
	}

	@Override
	public boolean isTrivialMonic() {
		return false;
	}

	@Override
	public Polynomial expand(IdealFactory factory) {
		NumericPrimitive primitive = primitive();
		Polynomial expandedPrimitive = primitive.expand(factory);

		if (primitive.equals(expandedPrimitive))
			return this;
		return (Polynomial) factory.power(expandedPrimitive, exponent());
	}

	@Override
	public String toString() {
		return primitive().atomString() + "^" + exponent();
	}

	@Override
	public int degree() {
		return exponent().getInt();
	}

	@Override
	public IdealKind idealKind() {
		return IdealKind.NTPrimitivePower;
	}

	@Override
	public Constant constantTerm(IdealFactory factory) {
		return factory.zero(type());
	}

}