Write a RationalNumber class.

build.gradle

@@ -11,6 +11,7 @@ repositories {
 }
 
 dependencies {
+    compile group: 'org.apache.commons', name: 'commons-math3', version: '3.6.1'
     compile 'com.moandjiezana.toml:toml4j:0.7.1'
     compile "org.jetbrains.kotlin:kotlin-stdlib-jre8"
     testCompile 'junit:junit:4.12'

src/main/java/org/nwapw/abacus/fx/AbacusController.java

@@ -216,7 +216,7 @@ public class AbacusController implements PluginListener {
         Callback<TableColumn<HistoryModel, String>, TableCell<HistoryModel, String>> cellFactory =
                 param -> new CopyableCell<>();
         Callback<ListView<ToggleablePlugin>, ListCell<ToggleablePlugin>> pluginCellFactory =
-                param -> new CheckBoxListCell<>(ToggleablePlugin::enabledProperty, new StringConverter<ToggleablePlugin>() {
+                param -> new CheckBoxListCell<>(ToggleablePlugin::getEnabledProperty, new StringConverter<ToggleablePlugin>() {
                     @Override
                     public String toString(ToggleablePlugin object) {
                         return object.getClassName().substring(object.getClassName().lastIndexOf('.') + 1);
@@ -224,7 +224,7 @@ public class AbacusController implements PluginListener {
 
                     @Override
                     public ToggleablePlugin fromString(String string) {
-                        return new ToggleablePlugin(true, string);
+                        return new ToggleablePlugin(string, true);
                     }
                 });
 
@@ -243,11 +243,11 @@ public class AbacusController implements PluginListener {
         enabledPluginView.setItems(enabledPlugins);
         enabledPluginView.setCellFactory(pluginCellFactory);
         inputColumn.setCellFactory(cellFactory);
-        inputColumn.setCellValueFactory(cell -> cell.getValue().inputProperty());
+        inputColumn.setCellValueFactory(cell -> cell.getValue().getInputProperty());
         parsedColumn.setCellFactory(cellFactory);
-        parsedColumn.setCellValueFactory(cell -> cell.getValue().parsedProperty());
+        parsedColumn.setCellValueFactory(cell -> cell.getValue().getParsedProperty());
         outputColumn.setCellFactory(cellFactory);
-        outputColumn.setCellValueFactory(cell -> cell.getValue().outputProperty());
+        outputColumn.setCellValueFactory(cell -> cell.getValue().getOutputProperty());
         coreTabPane.getSelectionModel().selectedItemProperty().addListener((observable, oldValue, newValue) -> {
             if (oldValue.equals(settingsTab)) alertIfApplyNeeded(true);
         });
@@ -343,8 +343,8 @@ public class AbacusController implements PluginListener {
         numberImplementationBox.getSelectionModel().select(toSelect);
         for (Class<?> pluginClass : abacus.getPluginManager().getLoadedPluginClasses()) {
             String fullName = pluginClass.getName();
-            ToggleablePlugin plugin = new ToggleablePlugin(!disabledPlugins.contains(fullName), fullName);
-            plugin.enabledProperty().addListener(e -> changesMade = true);
+            ToggleablePlugin plugin = new ToggleablePlugin(fullName, !disabledPlugins.contains(fullName));
+            plugin.getEnabledProperty().addListener(e -> changesMade = true);
             enabledPlugins.add(plugin);
         }
         functionList.addAll(manager.getAllFunctions());

src/main/java/org/nwapw/abacus/fx/HistoryModel.java

@@ -1,97 +0,0 @@
-package org.nwapw.abacus.fx;
-
-import javafx.beans.property.SimpleStringProperty;
-import javafx.beans.property.StringProperty;
-
-/**
- * The data model used for storing history entries.
- */
-public class HistoryModel {
-
-    /**
-     * The property used for displaying the column
-     * for the user input.
-     */
-    private final StringProperty input;
-    /**
-     * The property used for displaying the column
-     * that contains the parsed input.
-     */
-    private final StringProperty parsed;
-    /**
-     * The property used for displaying the column
-     * that contains the program output.
-     */
-    private final StringProperty output;
-
-    /**
-     * Creates a new history model with the given variables.
-     *
-     * @param input  the user input
-     * @param parsed the parsed input
-     * @param output the program output.
-     */
-    public HistoryModel(String input, String parsed, String output) {
-        this.input = new SimpleStringProperty();
-        this.parsed = new SimpleStringProperty();
-        this.output = new SimpleStringProperty();
-        this.input.setValue(input);
-        this.parsed.setValue(parsed);
-        this.output.setValue(output);
-    }
-
-    /**
-     * Gets the input property.
-     *
-     * @return the input property.
-     */
-    public StringProperty inputProperty() {
-        return input;
-    }
-
-    /**
-     * Gets the input.
-     *
-     * @return the input.
-     */
-    public String getInput() {
-        return input.get();
-    }
-
-    /**
-     * Gets the parsed input property.
-     *
-     * @return the parsed input property.
-     */
-    public StringProperty parsedProperty() {
-        return parsed;
-    }
-
-    /**
-     * Gets the parsed input.
-     *
-     * @return the parsed input.
-     */
-    public String getParsed() {
-        return parsed.get();
-    }
-
-    /**
-     * Gets the output property.
-     *
-     * @return the output property.
-     */
-    public StringProperty outputProperty() {
-        return output;
-    }
-
-    /**
-     * Gets the program output.
-     *
-     * @return the output.
-     */
-    public String getOutput() {
-        return output.get();
-    }
-
-}

src/main/java/org/nwapw/abacus/fx/ToggleablePlugin.java

@@ -1,60 +0,0 @@
-package org.nwapw.abacus.fx;
-
-import javafx.beans.property.BooleanProperty;
-import javafx.beans.property.SimpleBooleanProperty;
-
-/**
- * Class that represents an entry in the plugin check box list.
- * The changes from this property are written to the config on application.
- */
-public class ToggleablePlugin {
-
-    /**
-     * The property that determines whether the plugin will be enabled.
-     */
-    private final BooleanProperty enabled;
-    /**
-     * The name of the class this entry toggles.
-     */
-    private final String className;
-
-    /**
-     * Creates a new toggleable plugin with the given properties.
-     *
-     * @param enabled   the enabled / disabled state at the beginning.
-     * @param className the name of the class this plugin toggles.
-     */
-    public ToggleablePlugin(boolean enabled, String className) {
-        this.enabled = new SimpleBooleanProperty();
-        this.enabled.setValue(enabled);
-        this.className = className;
-    }
-
-    /**
-     * Gets the enabled property of this plugin.
-     *
-     * @return the enabled property.
-     */
-    public BooleanProperty enabledProperty() {
-        return enabled;
-    }
-
-    /**
-     * Checks if this plugin entry should be enabled.
-     *
-     * @return whether this plugin will be enabled.
-     */
-    public boolean isEnabled() {
-        return enabled.get();
-    }
-
-    /**
-     * Gets the class name this plugin toggles.
-     *
-     * @return the class name that should be disabled.
-     */
-    public String getClassName() {
-        return className;
-    }
-
-}

src/main/java/org/nwapw/abacus/number/NaiveNumber.java

@@ -128,5 +128,9 @@ public class NaiveNumber extends NumberInterface {
         return Double.toString(Math.round(value * shiftBy) / shiftBy);
     }
 
+    @Override
+    public NumberInterface getMaxError(){
+        return new NaiveNumber(Math.pow(10, -18));
+    }
 }
 

src/main/java/org/nwapw/abacus/number/NumberInterface.java

@@ -255,4 +255,11 @@ public abstract class NumberInterface {
         return promoteToInternal(toClass);
     }
 
+    /**
+     * Returns the smallest error this instance can tolerate depending
+     * on its precision and value.
+     * @return the smallest error that should be permitted in calculations.
+     */
+    public abstract NumberInterface getMaxError();
+
 }

src/main/java/org/nwapw/abacus/number/PreciseNumber.java

@@ -1,7 +1,8 @@
 package org.nwapw.abacus.number;
 
 import java.math.BigDecimal;
-import java.math.RoundingMode;
+import java.math.BigInteger;
+import java.math.MathContext;
 
 /**
  * A number that uses a BigDecimal to store its value,
@@ -22,6 +23,21 @@ public class PreciseNumber extends NumberInterface {
      */
     public static final PreciseNumber TEN = new PreciseNumber(BigDecimal.TEN);
 
+    /**
+     * The number of extra significant figures kept in calculations before rounding for output.
+     */
+    private static int numExtraInternalSigFigs = 15;
+
+    /**
+     * MathContext that is used when rounding a number prior to output.
+     */
+    private static MathContext outputContext = new MathContext(50);
+
+    /**
+     * MathContext that is actually used in calculations.
+     */
+    private static MathContext internalContext = new MathContext(outputContext.getPrecision()+numExtraInternalSigFigs);
+
     /**
      * The value of the PreciseNumber.
      */
@@ -46,9 +62,18 @@ public class PreciseNumber extends NumberInterface {
         this.value = value;
     }
 
+    /**
+     * Constructs a precise number from the given BigInteger.
+     *
+     * @param value a BigInteger object representing the value of the number.
+     */
+    public PreciseNumber(BigInteger value) {
+        this.value = new BigDecimal(value);
+    }
+
     @Override
     public int getMaxPrecision() {
-        return 65;
+        return internalContext.getPrecision();
     }
 
     @Override
@@ -58,7 +83,7 @@ public class PreciseNumber extends NumberInterface {
 
     @Override
     public NumberInterface divideInternal(NumberInterface divisor) {
-        return new PreciseNumber(value.divide(((PreciseNumber) divisor).value, this.getMaxPrecision(), RoundingMode.HALF_UP));
+        return new PreciseNumber(value.divide(((PreciseNumber) divisor).value, internalContext));
     }
 
     @Override
@@ -147,7 +172,11 @@ public class PreciseNumber extends NumberInterface {
 
     @Override
     public String toString() {
-        BigDecimal rounded = value.setScale(getMaxPrecision() - 15, RoundingMode.HALF_UP);
-        return rounded.stripTrailingZeros().toPlainString();
+        return value.round(outputContext).toString();
+    }
+
+    @Override
+    public NumberInterface getMaxError(){
+        return new PreciseNumber(value.ulp()).multiplyInternal(TEN.intPowInternal(value.precision()-internalContext.getPrecision()));
     }
 }

src/main/java/org/nwapw/abacus/number/RationalNumber.java

@@ -0,0 +1,115 @@
+package org.nwapw.abacus.number;
+
+import org.apache.commons.math3.fraction.BigFraction;
+import org.apache.commons.math3.fraction.Fraction;
+
+import java.math.BigInteger;
+
+public class RationalNumber extends NumberInterface{
+
+    static final RationalNumber ONE = new RationalNumber(BigFraction.ONE);
+
+    /**
+     * The value of the number.
+     */
+    private BigFraction value;
+
+    /**
+     * Constructs a new instance with the given value.
+     * @param value
+     */
+    public RationalNumber(BigFraction value){
+        this.value = value;
+    }
+
+    @Override
+    public int getMaxPrecision() {
+        return 0;
+    }
+
+    @Override
+    protected NumberInterface multiplyInternal(NumberInterface multiplier) {
+        return new RationalNumber(value.multiply(((RationalNumber)multiplier).value));
+    }
+
+    @Override
+    protected NumberInterface divideInternal(NumberInterface divisor) {
+        return new RationalNumber(value.divide(((RationalNumber)divisor).value));
+    }
+
+    @Override
+    protected NumberInterface addInternal(NumberInterface summand) {
+        return new RationalNumber(value.add(((RationalNumber)summand).value));
+    }
+
+    @Override
+    protected NumberInterface subtractInternal(NumberInterface subtrahend) {
+        return new RationalNumber(value.subtract(((RationalNumber)subtrahend).value));
+    }
+
+    @Override
+    protected NumberInterface negateInternal() {
+        return new RationalNumber(value.negate());
+    }
+
+    @Override
+    protected NumberInterface intPowInternal(int exponent) {
+        return new RationalNumber(value.pow(exponent));
+    }
+
+    @Override
+    public int compareTo(NumberInterface number) {
+        return value.compareTo(((RationalNumber)number).value);
+    }
+
+    @Override
+    public int signum() {
+        return value.getNumerator().signum();
+    }
+
+    @Override
+    protected NumberInterface ceilingInternal() {
+        if(value.getNumeratorAsInt() != 1){
+            return floorInternal().add(ONE);
+        }
+        return this;
+    }
+
+    @Override
+    protected NumberInterface floorInternal() {
+        BigInteger floor = value.bigDecimalValue().toBigInteger();
+        if(value.compareTo(BigFraction.ZERO) < 0 && value.getDenominatorAsInt() != 1){
+            floor = floor.subtract(BigInteger.ONE);
+        }
+        return new RationalNumber(new BigFraction(floor));
+    }
+
+    @Override
+    protected NumberInterface fractionalPartInternal() {
+        return this.subtractInternal(floorInternal());
+    }
+
+    @Override
+    public int intValue() {
+        return 0;
+    }
+
+    @Override
+    protected NumberInterface promoteToInternal(Class<? extends NumberInterface> toClass) {
+        return null;
+    }
+
+    @Override
+    public NumberInterface getMaxError() {
+        return toPreciseNumber().getMaxError();
+    }
+
+    @Override
+    public String toString(){
+        return toPreciseNumber().toString();
+    }
+
+    PreciseNumber toPreciseNumber(){
+        return (PreciseNumber) new PreciseNumber(value.getNumerator()).divideInternal(new PreciseNumber(value.getDenominator()));
+    }
+}

src/main/java/org/nwapw/abacus/plugin/StandardPlugin.java

@@ -188,7 +188,7 @@ public class StandardPlugin extends Plugin {
          */
         private NumberInterface getLogPartialSum(NumberInterface x) {
 
-            NumberInterface maxError = getMaxError(x);
+            NumberInterface maxError = x.getMaxError();
             x = x.subtract(NaiveNumber.ONE.promoteTo(x.getClass())); //Terms used are for log(x+1).
             NumberInterface currentNumerator = x, currentTerm = x, sum = x;
             int n = 1;
@@ -207,7 +207,7 @@ public class StandardPlugin extends Plugin {
          * @return the value of log(2) with the appropriate precision.
          */
         private NumberInterface getLog2(NumberInterface number) {
-            NumberInterface maxError = getMaxError(number);
+            NumberInterface maxError = number.getMaxError();
             //NumberInterface errorBound = fromInt(number.getClass(), 1);
             //We'll use the series \sigma_{n >= 1) ((1/3^n + 1/4^n) * 1/n)
             //In the following, a=1/3^n, b=1/4^n, c = 1/n.
@@ -301,16 +301,11 @@ public class StandardPlugin extends Plugin {
 
         @Override
         protected NumberInterface applyInternal(NumberInterface[] params) {
-            NumberInterface maxError = getMaxError(params[0]);
+            NumberInterface maxError = params[0].getMaxError();
             int n = 0;
-            if (params[0].signum() <= 0) {
-                NumberInterface currentTerm = NaiveNumber.ONE.promoteTo(params[0].getClass()), sum = currentTerm;
-                while (FUNCTION_ABS.apply(currentTerm).compareTo(maxError) > 0) {
-                    n++;
-                    currentTerm = currentTerm.multiply(params[0]).divide((new NaiveNumber(n)).promoteTo(params[0].getClass()));
-                    sum = sum.add(currentTerm);
-                }
-                return sum;
+            if (params[0].signum() < 0) {
+                NumberInterface[] negatedParams = {params[0].negate()};
+               return fromInt(params[0].getClass(), 1).divide(applyInternal(negatedParams));
             } else {
                 //We need n such that x^(n+1) * 3^ceil(x) <= maxError * (n+1)!.
                 //right and left refer to lhs and rhs in the above inequality.
@@ -352,7 +347,7 @@ public class StandardPlugin extends Plugin {
                 return NaiveNumber.ONE.promoteTo(params[1].getClass());
             //Detect integer bases:
             if(params[0].fractionalPart().compareTo(fromInt(params[0].getClass(), 0)) == 0
-                    && FUNCTION_ABS.apply(params[0]).compareTo(fromInt(params[0].getClass(), Integer.MAX_VALUE)) < 0
+                    && FUNCTION_ABS.apply(params[1]).compareTo(fromInt(params[0].getClass(), Integer.MAX_VALUE)) < 0
                     && FUNCTION_ABS.apply(params[1]).compareTo(fromInt(params[1].getClass(), 1)) >= 0){
                 NumberInterface[] newParams = {params[0], params[1].fractionalPart()};
                 return params[0].intPow(params[1].floor().intValue()).multiply(applyInternal(newParams));
@@ -476,16 +471,6 @@ public class StandardPlugin extends Plugin {
         return sum;
     }
 
-    /**
-     * Returns the maximum error based on the precision of the class of number.
-     *
-     * @param number Any instance of the NumberInterface in question (should return an appropriate precision).
-     * @return the maximum error.
-     */
-    private static NumberInterface getMaxError(NumberInterface number) {
-        return fromInt(number.getClass(), 10).intPow(-number.getMaxPrecision());
-    }
-
     /**
      * A factorial function that uses memoization for each number class; it efficiently
      * computes factorials of non-negative integers.
@@ -517,7 +502,7 @@ public class StandardPlugin extends Plugin {
      */
     private static NumberInterface sinTaylor(NumberInterface x) {
         NumberInterface power = x, multiplier = x.multiply(x).negate(), currentTerm = x, sum = x;
-        NumberInterface maxError = getMaxError(x);
+        NumberInterface maxError = x.getMaxError();
         int n = 1;
         do {
             n += 2;

src/main/kotlin/org/nwapw/abacus/fx/HistoryModel.kt

@@ -0,0 +1,32 @@
+package org.nwapw.abacus.fx
+
+import javafx.beans.property.SimpleStringProperty
+
+/**
+ * A model representing an input / output in the calculator.
+ *
+ * The HistoryModel class stores a record of a single user-provided input,
+ * its parsed form as it was interpreted by the calculator, and the output
+ * that was provided by the calculator. These are represented as properties
+ * to allow easy access by JavaFX cells.
+ *
+ * @param input the user input
+ * @param parsed the parsed version of the input.
+ * @param output the output string.
+ */
+class HistoryModel(input: String, parsed: String, output: String){
+
+    /**
+     * The property that holds the input.
+     */
+    val inputProperty = SimpleStringProperty(input)
+    /**
+     * The property that holds the parsed input.
+     */
+    val parsedProperty = SimpleStringProperty(parsed)
+    /**
+     * The property that holds the output.
+     */
+    val outputProperty = SimpleStringProperty(output)
+
+}

src/main/kotlin/org/nwapw/abacus/fx/ToggleablePlugin.kt

@@ -0,0 +1,31 @@
+package org.nwapw.abacus.fx
+
+import javafx.beans.property.SimpleBooleanProperty
+
+/**
+ * A model representing a plugin that can be disabled or enabled.
+ *
+ * ToggleablePlugin is a model that is used to present to the user the option
+ * of disabling / enabling plugins. The class name in this plugin is stored if
+ * its "enabledPropery" is false, essentially blacklisting the plugin.
+ *
+ * @param className the name of the class that this model concerns.
+ * @param enabled whether or not the model should start enabled.
+ */
+class ToggleablePlugin (val className: String, enabled: Boolean) {
+
+    /**
+     * The property used to interact with JavaFX components.
+     */
+    val enabledProperty = SimpleBooleanProperty(enabled)
+
+    /**
+     * Checks whether this plugin is currently enabled or not.
+     *
+     * @return true if it is enabled, false otherwise.
+     */
+    fun isEnabled(): Boolean {
+        return enabledProperty.value
+    }
+
+}

src/test/java/org/nwapw/abacus/tests/CalculationTests.java

@@ -88,8 +88,8 @@ public class CalculationTests {
     public void testExp(){
         testOutput("exp0", "exp(0)", "1");
         testOutput("exp1", "exp(1)", "2.718281828459045235360287471352662497757247");
-        testOutput("exp300", "exp(300)", "19424263952412559365842088360176992193662086");
-        testOutput("exp300", "exp(300)", "19424263952412559365842088360176992193662086");
+        testOutput("exp300", "exp(300)", "1.9424263952412559365842088360176992193662086");
+        testOutput("exp(-500)", "exp((500)`)", "7.1245764067412855315491573771227552469277568");
     }
 
     @Test
@@ -99,6 +99,9 @@ public class CalculationTests {
         testOutput("2^1", "(2^1)", "2");
         testOutput("2^-1", "(2^(1)`)", "0.5");
         testOutput("2^50", "(2^50)", "112589990684262");
+        testOutput("7^(-sqrt2*17)", "(7^((sqrt(2)*17))`)", "4.81354609155297814551845300063563");
+        testEvalError("0^0", "(0^0)");
+        testEvalError("(-13)^.9999", "((13)`^0.9999)");
     }
 
 }