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

@@ -255,7 +255,13 @@ public class AbacusController implements PluginListener {
         abacus = new Abacus(new Configuration(CONFIG_FILE));
         PluginManager abacusPluginManager = abacus.getPluginManager();
         abacusPluginManager.addListener(this);
-        performScan();
+        abacusPluginManager.addInstantiated(new StandardPlugin(abacus.getPluginManager()));
+        try {
+            ClassFinder.loadJars("plugins").forEach(abacusPluginManager::addClass);
+        } catch (IOException | ClassNotFoundException e) {
+            e.printStackTrace();
+        }
+        abacusPluginManager.reload();
 
         computationLimitField.setText(Double.toString(abacus.getConfiguration().getComputationDelay()));
         computationLimitField.textProperty().addListener((observable, oldValue, newValue) -> {
@@ -305,19 +311,6 @@ public class AbacusController implements PluginListener {
         reloadAlertShown = false;
     }
 
-    @FXML
-    public void performScan(){
-        PluginManager abacusPluginManager = abacus.getPluginManager();
-        abacusPluginManager.removeAll();
-        abacusPluginManager.addInstantiated(new StandardPlugin(abacus.getPluginManager()));
-        try {
-            ClassFinder.loadJars("plugins").forEach(abacusPluginManager::addClass);
-        } catch (IOException | ClassNotFoundException e) {
-            e.printStackTrace();
-        }
-        abacusPluginManager.reload();
-    }
-
     @FXML
     public void performReload() {
         alertIfApplyNeeded(true);

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

@@ -240,7 +240,6 @@ public abstract class NumberInterface {
      * @param toClass the class to promote to.
      * @return the resulting new instance.
      */
-    @Deprecated
     protected abstract NumberInterface promoteToInternal(Class<? extends NumberInterface> toClass);
 
     /**
@@ -251,7 +250,6 @@ public abstract class NumberInterface {
      * @param toClass the class to promote to.
      * @return the resulting new instance.
      */
-    @Deprecated
     public final NumberInterface promoteTo(Class<? extends NumberInterface> toClass) {
         checkInterrupted();
         return promoteToInternal(toClass);

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

@@ -1,6 +1,7 @@
 package org.nwapw.abacus.number;
 
 import java.math.BigDecimal;
+import java.math.BigInteger;
 import java.math.MathContext;
 
 /**
@@ -61,6 +62,15 @@ 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 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/NumberImplementation.java

@@ -14,7 +14,7 @@ public abstract class NumberImplementation {
     /**
      * The list of paths through which this implementation can be promoted.
      */
-    private Map<Class<? extends NumberInterface>, Function<NumberInterface, NumberInterface>> promotionPaths;
+    protected Map<Class<? extends NumberInterface>, Function<NumberInterface, NumberInterface>> promotionPaths;
     /**
      * The implementation class for this implementation.
      */

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

@@ -187,24 +187,6 @@ public class PluginManager {
         }
     }
 
-    /**
-     * Removes the plugin with the given class from the manager.
-     * @param toRemove the plugin to remove.
-     */
-    public void removeClass(Class<? extends Plugin> toRemove){
-        if(!loadedPluginClasses.contains(toRemove)) return;
-        plugins.removeIf(plugin -> plugin.getClass() == toRemove);
-        loadedPluginClasses.remove(toRemove);
-    }
-
-    /**
-     * Removes all plugins from this plugin manager.
-     */
-    public void removeAll(){
-        loadedPluginClasses.clear();
-        plugins.clear();
-    }
-
     /**
      * Loads all the plugins in the PluginManager.
      */

src/main/java/org/nwapw/abacus/tree/Reducer.java

@@ -0,0 +1,19 @@
+package org.nwapw.abacus.tree;
+
+/**
+ * Interface used to reduce a tree into a single value.
+ *
+ * @param <T> the value to reduce into.
+ */
+public interface Reducer<T> {
+
+    /**
+     * Reduces the given tree into a single value of type T.
+     *
+     * @param node     the node being passed in to be reduced.
+     * @param children the already-reduced children of this node.
+     * @return the resulting value from the reduce.
+     */
+    public T reduceNode(TreeNode node, Object... children);
+
+}

src/main/kotlin/org/nwapw/abacus/tree/FunctionNode.kt

@@ -16,7 +16,7 @@ data class FunctionNode(val function: String) : TreeNode() {
     val children: MutableList<TreeNode> = mutableListOf()
 
     override fun <T : Any> reduce(reducer: Reducer<T>): T? {
-        val children = Array<Any>(children.size, { children[it].reduce(reducer) ?: return null; })
+        val children = Array<Any?>(children.size, { children[it].reduce(reducer) ?: return null; })
         return reducer.reduceNode(this, *children)
     }
 

src/main/kotlin/org/nwapw/abacus/tree/Reducer.kt

@@ -1,19 +0,0 @@
-package org.nwapw.abacus.tree
-
-/**
- * Reducer interface that takes a tree and returns a single value.
- *
- * The reducer walks the tree, visiting the children first, converting them into
- * a value, and then attempts to reduce the parent. Eventually, the single final value is returned.
- */
-interface Reducer <out T> {
-
-    /**
-     * Reduces the given tree node, given its already reduced children.
-     *
-     * @param treeNode the tree node to reduce.
-     * @param children the list of children, of type T.
-     */
-    fun reduceNode(treeNode: TreeNode, vararg children: Any) : T?
-
-}

src/main/resources/abacus.fxml

@@ -57,7 +57,6 @@
                         <Button text="Apply" onAction="#performSave"/>
                         <Button text="Reload Plugins" onAction="#performReload"/>
                         <Button text="Apply and Reload" onAction="#performSaveAndReload"/>
-                        <Button text="Scan Plugins" onAction="#performScan"/>
                     </FlowPane>
                 </GridPane>
             </Tab>