Implement preciseNumber for arbitrary precision.

This commit is contained in:
Arthur Drobot 2017-07-28 11:38:22 -07:00
parent c9fad36d16
commit c184b55738
3 changed files with 116 additions and 1 deletions

View File

@ -88,6 +88,9 @@ public class NaiveNumber implements NumberInterface {
@Override
public NumberInterface promoteTo(Class<? extends NumberInterface> toClass) {
if(toClass == this.getClass()) return this;
else if(toClass == PreciseNumber.class){
return new PreciseNumber(Double.toString(value));
}
return null;
}

View File

@ -0,0 +1,112 @@
package org.nwapw.abacus.number;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.math.MathContext;
import java.math.RoundingMode;
public class PreciseNumber implements NumberInterface{
/**
* The number one.
*/
static final PreciseNumber ONE = new PreciseNumber(BigDecimal.ONE);
/**
* The number zero.
*/
static final PreciseNumber ZERO = new PreciseNumber(BigDecimal.ZERO);
/**
* The number ten.
*/
static final PreciseNumber TEN = new PreciseNumber(BigDecimal.TEN);
BigDecimal value = new BigDecimal("0");
/**
* Constructs a precise number from the given string.
* @param string a string representation of the number meeting the same conditions
* as the BidDecimal(String) constructor.
*/
public PreciseNumber(String string){
value = new BigDecimal(string);
}
/**
* Constructs a precise number from the given BigDecimal.
* @param value a BigDecimal object representing the value of the number.
*/
public PreciseNumber(BigDecimal value){
this.value = value;
}
@Override
public int precision() {
return 54;
}
@Override
public NumberInterface multiply(NumberInterface multiplier) {
return new PreciseNumber(value.multiply(((PreciseNumber) multiplier).value));
}
@Override
public NumberInterface divide(NumberInterface divisor) {
return new PreciseNumber(value.divide(((PreciseNumber) divisor).value, this.precision(), RoundingMode.HALF_UP));
}
@Override
public NumberInterface add(NumberInterface summand) {
return new PreciseNumber(value.add(((PreciseNumber) summand).value));
}
@Override
public NumberInterface subtract(NumberInterface subtrahend) {
return new PreciseNumber(value.subtract(((PreciseNumber) subtrahend).value));
}
@Override
public NumberInterface intPow(int exponent) {
if(exponent == 0){
return PreciseNumber.ONE;
}
boolean takeReciprocal = exponent < 0;
exponent = Math.abs(exponent);
NumberInterface power = this;
for(int currentExponent = 1; currentExponent < exponent; currentExponent++){
power = power.multiply(this);
}
if(takeReciprocal){
power = PreciseNumber.ONE.divide(power);
}
return power;
}
@Override
public int compareTo(NumberInterface number) {
return value.compareTo(((PreciseNumber) number).value);
}
@Override
public int signum() {
return value.signum();
}
@Override
public NumberInterface negate(){
return new PreciseNumber(value.negate());
}
@Override
public NumberInterface promoteTo(Class<? extends NumberInterface> toClass) {
if(toClass == this.getClass()){
return this;
}
return null;
}
@Override
public String toString() {
BigDecimal rounded = value.setScale(precision() - 4, RoundingMode.HALF_UP);
return rounded.stripTrailingZeros().toPlainString();
}
}

View File

@ -228,7 +228,7 @@ public class StandardPlugin extends Plugin {
@Override
protected NumberInterface applyInternal(NumberInterface[] params) {
return StandardPlugin.this.getOperator("^").getFunction().apply(params[0], (new NaiveNumber(0.5)));
return StandardPlugin.this.getOperator("^").getFunction().apply(params[0], ((new NaiveNumber(0.5)).promoteTo(params[0].getClass())));
}
});
}