Decrease test intensity to prevent travis CI from killing gradle.

# Conflicts:
#	src/main/java/org/nwapw/abacus/fx/AbacusController.java
#	src/main/java/org/nwapw/abacus/plugin/StandardPlugin.java

src/main/java/org/nwapw/abacus/Abacus.java

@@ -2,21 +2,16 @@ package org.nwapw.abacus;
 
 import org.nwapw.abacus.config.Configuration;
 import org.nwapw.abacus.fx.AbacusApplication;
-import org.nwapw.abacus.number.NaiveNumber;
 import org.nwapw.abacus.number.NumberInterface;
 import org.nwapw.abacus.parsing.LexerTokenizer;
 import org.nwapw.abacus.parsing.ShuntingYardParser;
 import org.nwapw.abacus.parsing.TreeBuilder;
-import org.nwapw.abacus.plugin.ClassFinder;
+import org.nwapw.abacus.plugin.NumberImplementation;
 import org.nwapw.abacus.plugin.PluginManager;
 import org.nwapw.abacus.plugin.StandardPlugin;
 import org.nwapw.abacus.tree.NumberReducer;
 import org.nwapw.abacus.tree.TreeNode;
 
-import java.io.File;
-import java.io.IOException;
-import java.lang.reflect.InvocationTargetException;
-
 /**
  * The main calculator class. This is responsible
  * for piecing together all of the components, allowing
@@ -25,13 +20,9 @@ import java.lang.reflect.InvocationTargetException;
 public class Abacus {
 
     /**
-     * The default implementation to use for the number representation.
+     * The default number implementation to be used if no other one is available / selected.
      */
-    public static final Class<? extends NumberInterface> DEFAULT_NUMBER = NaiveNumber.class;
+    public static final NumberImplementation DEFAULT_IMPLEMENTATION = StandardPlugin.IMPLEMENTATION_NAIVE;
-    /**
-     * The file used for saving and loading configuration.
-     */
-    public static final File CONFIG_FILE = new File("config.toml");
 
     /**
      * The plugin manager responsible for
@@ -56,25 +47,16 @@ public class Abacus {
     /**
      * Creates a new instance of the Abacus calculator.
      */
-    public Abacus() {
+    public Abacus(Configuration configuration) {
         pluginManager = new PluginManager(this);
         numberReducer = new NumberReducer(this);
-        configuration = new Configuration(CONFIG_FILE);
+        this.configuration = new Configuration(configuration);
-        configuration.saveTo(CONFIG_FILE);
         LexerTokenizer lexerTokenizer = new LexerTokenizer();
         ShuntingYardParser shuntingYardParser = new ShuntingYardParser(this);
         treeBuilder = new TreeBuilder<>(lexerTokenizer, shuntingYardParser);
 
-        pluginManager.addListener(lexerTokenizer);
         pluginManager.addListener(shuntingYardParser);
-        pluginManager.addInstantiated(new StandardPlugin(pluginManager));
+        pluginManager.addListener(lexerTokenizer);
-        try {
-            ClassFinder.loadJars("plugins")
-                    .forEach(plugin -> pluginManager.addClass(plugin));
-        } catch (IOException | ClassNotFoundException e) {
-            e.printStackTrace();
-        }
-        pluginManager.load();
     }
 
     public static void main(String[] args) {
@@ -147,15 +129,10 @@ public class Abacus {
      * @return the resulting number.
      */
     public NumberInterface numberFromString(String numberString) {
-        Class<? extends NumberInterface> toInstantiate =
+        NumberImplementation toInstantiate =
-                pluginManager.numberFor(configuration.getNumberImplementation());
+                pluginManager.numberImplementationFor(configuration.getNumberImplementation());
-        if (toInstantiate == null) toInstantiate = DEFAULT_NUMBER;
+        if (toInstantiate == null) toInstantiate = DEFAULT_IMPLEMENTATION;
 
-        try {
+        return toInstantiate.instanceForString(numberString);
-            return toInstantiate.getConstructor(String.class).newInstance(numberString);
-        } catch (InstantiationException | IllegalAccessException | NoSuchMethodException | InvocationTargetException e) {
-            e.printStackTrace();
-        }
-        return null;
     }
 }

src/main/java/org/nwapw/abacus/config/Configuration.java

@@ -20,7 +20,7 @@ public class Configuration {
      */
     private static final String DEFAULT_CONFIG =
             "numberImplementation = \"naive\"\n" +
-            "disabledPlugins = []";
+                    "disabledPlugins = []";
     /**
      * The defaults TOML object, parsed from the string.
      */
@@ -40,29 +40,41 @@ public class Configuration {
     private Set<String> disabledPlugins = new HashSet<>();
 
     /**
-     * Creates a new configuration with the given values.
+     * Creates a new configuration form the given configuration.
-     * @param numberImplementation the number implementation, like "naive" or "precise"
+     *
-     * @param disabledPlugins the list of disabled plugins.
+     * @param copyFrom the configuration to copy.
      */
-    public Configuration(String numberImplementation, String[] disabledPlugins){
+    public Configuration(Configuration copyFrom){
+        copyFrom(copyFrom);
+    }
+
+    /**
+     * Creates a new configuration with the given values.
+     *
+     * @param numberImplementation the number implementation, like "naive" or "precise"
+     * @param disabledPlugins      the list of disabled plugins.
+     */
+    public Configuration(String numberImplementation, String[] disabledPlugins) {
         this.numberImplementation = numberImplementation;
         this.disabledPlugins.addAll(Arrays.asList(disabledPlugins));
     }
 
     /**
      * Loads a configuration from a given file, keeping non-specified fields default.
+     *
      * @param fromFile the file to load from.
      */
-    public Configuration(File fromFile){
+    public Configuration(File fromFile) {
-        if(!fromFile.exists()) return;
+        if (!fromFile.exists()) return;
         copyFrom(new Toml(DEFAULT_TOML).read(fromFile).to(Configuration.class));
     }
 
     /**
      * Copies the values from the given configuration into this one.
+     *
      * @param otherConfiguration the configuration to copy from.
      */
-    public void copyFrom(Configuration otherConfiguration){
+    public void copyFrom(Configuration otherConfiguration) {
         this.numberImplementation = otherConfiguration.numberImplementation;
         this.disabledPlugins.addAll(otherConfiguration.disabledPlugins);
     }
@@ -70,10 +82,11 @@ public class Configuration {
     /**
      * Saves this configuration to the given file, creating
      * any directories that do not exist.
+     *
      * @param file the file to save to.
      */
-    public void saveTo(File file){
+    public void saveTo(File file) {
-        if(file.getParentFile() != null) file.getParentFile().mkdirs();
+        if (file.getParentFile() != null) file.getParentFile().mkdirs();
         try {
             TOML_WRITER.write(this, file);
         } catch (IOException e) {
@@ -81,8 +94,18 @@ public class Configuration {
         }
     }
 
+    /**
+     * Gets the value of this configuration as a string.
+     *
+     * @return the string that represents this configuration.
+     */
+    public String asTomlString(){
+        return TOML_WRITER.write(this);
+    }
+
     /**
      * Gets the number implementation from this configuration.
+     *
      * @return the number implementation.
      */
     public String getNumberImplementation() {
@@ -91,6 +114,7 @@ public class Configuration {
 
     /**
      * Sets the number implementation for the configuration
+     *
      * @param numberImplementation the number implementation.
      */
     public void setNumberImplementation(String numberImplementation) {
@@ -99,6 +123,7 @@ public class Configuration {
 
     /**
      * Gets the list of disabled plugins.
+     *
      * @return the list of disabled plugins.
      */
     public Set<String> getDisabledPlugins() {

src/main/java/org/nwapw/abacus/function/Function.java

@@ -1,10 +1,6 @@
 package org.nwapw.abacus.function;
 
-import org.nwapw.abacus.number.NaiveNumber;
 import org.nwapw.abacus.number.NumberInterface;
-import org.nwapw.abacus.number.PreciseNumber;
-
-import java.util.HashMap;
 
 /**
  * A function that operates on one or more
@@ -12,15 +8,6 @@ import java.util.HashMap;
  */
 public abstract class Function {
 
-    /**
-     * A map to correctly promote different number implementations to each other.
-     */
-    private static final HashMap<Class<? extends NumberInterface>, Integer> priorityMap =
-            new HashMap<Class<? extends NumberInterface>, Integer>() {{
-                put(NaiveNumber.class, 0);
-                put(PreciseNumber.class, 1);
-            }};
-
     /**
      * Checks whether the given params will work for the given function.
      *

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

@@ -1,5 +1,6 @@
 package org.nwapw.abacus.fx;
 
+import javafx.application.Platform;
 import javafx.collections.FXCollections;
 import javafx.collections.ObservableList;
 import javafx.fxml.FXML;
@@ -11,10 +12,14 @@ import javafx.util.StringConverter;
 import org.nwapw.abacus.Abacus;
 import org.nwapw.abacus.config.Configuration;
 import org.nwapw.abacus.number.NumberInterface;
+import org.nwapw.abacus.plugin.ClassFinder;
 import org.nwapw.abacus.plugin.PluginListener;
 import org.nwapw.abacus.plugin.PluginManager;
+import org.nwapw.abacus.plugin.StandardPlugin;
 import org.nwapw.abacus.tree.TreeNode;
 
+import java.io.File;
+import java.io.IOException;
 import java.util.Set;
 
 
@@ -24,6 +29,10 @@ import java.util.Set;
  */
 public class AbacusController implements PluginListener {
 
+    /**
+     * The file used for saving and loading configuration.
+     */
+    public static final File CONFIG_FILE = new File("config.toml");
     /**
      * The title for the apply alert dialog.
      */
@@ -36,7 +45,7 @@ public class AbacusController implements PluginListener {
      * The text for the dialog that is shown if settings haven't been applied.
      */
     private static final String APPLY_MSG_TEXT = "You have made changes to the configuration, however, you haven't pressed \"Apply\". " +
-                "The changes to the configuration will not be present in the calculator until \"Apply\" is pressed.";
+            "The changes to the configuration will not be present in the calculator until \"Apply\" is pressed.";
     /**
      * Constant string that is displayed if the text could not be lexed or parsed.
      */
@@ -45,7 +54,10 @@ public class AbacusController implements PluginListener {
      * Constant string that is displayed if the tree could not be reduced.
      */
     private static final String ERR_EVAL = "Evaluation Error";
-
+    /**
+     * Constant string that is displayed if the calculations are stopped before they are done.
+     */
+    private static final String ERR_STOP = "Stopped";
     @FXML
     private TabPane coreTabPane;
     @FXML
@@ -83,6 +95,7 @@ public class AbacusController implements PluginListener {
     private ObservableList<String> numberImplementationOptions;
 
     /**
+     * <<<<<<< HEAD
      * The list of plugin objects that can be toggled on and off,
      * and, when reloaded, get added to the plugin manager's black list.
      */
@@ -92,6 +105,20 @@ public class AbacusController implements PluginListener {
      * The abacus instance used for changing the plugin configuration.
      */
     private Abacus abacus;
+    /**
+     * Thread used for calculating.
+     */
+    private Thread calcThread;
+
+    /**
+     * Checks whether the calculator is calculating.
+     */
+    private boolean calculating;
+
+    /**
+     * Seconds delayed for timer;
+     */
+    private double delay = 0;
 
     /**
      * Boolean which represents whether changes were made to the configuration.
@@ -110,15 +137,15 @@ public class AbacusController implements PluginListener {
      * Alerts the user if the changes they made
      * have not yet been applied.
      */
-    private void alertIfApplyNeeded(boolean ignorePrevious){
+    private void alertIfApplyNeeded(boolean ignorePrevious) {
-        if(changesMade && (!reloadAlertShown || ignorePrevious)) {
+        if (changesMade && (!reloadAlertShown || ignorePrevious)) {
             reloadAlertShown = true;
             reloadAlert.showAndWait();
         }
     }
 
     @FXML
-    public void initialize(){
+    public void initialize() {
         Callback<TableColumn<HistoryModel, String>, TableCell<HistoryModel, String>> cellFactory =
                 param -> new CopyableCell<>();
         Callback<ListView<ToggleablePlugin>, ListCell<ToggleablePlugin>> pluginCellFactory =
@@ -150,12 +177,19 @@ public class AbacusController implements PluginListener {
         outputColumn.setCellFactory(cellFactory);
         outputColumn.setCellValueFactory(cell -> cell.getValue().outputProperty());
         coreTabPane.getSelectionModel().selectedItemProperty().addListener((observable, oldValue, newValue) -> {
-            if(oldValue.equals(settingsTab)) alertIfApplyNeeded(true);
+            if (oldValue.equals(settingsTab)) alertIfApplyNeeded(true);
         });
 
-        abacus = new Abacus();
+        abacus = new Abacus(new Configuration(CONFIG_FILE));
-        abacus.getPluginManager().addListener(this);
+        PluginManager abacusPluginManager = abacus.getPluginManager();
-        abacus.getPluginManager().reload();
+        abacusPluginManager.addListener(this);
+        abacusPluginManager.addInstantiated(new StandardPlugin(abacus.getPluginManager()));
+        try {
+            ClassFinder.loadJars("plugins").forEach(abacusPluginManager::addClass);
+        } catch (IOException | ClassNotFoundException e) {
+            e.printStackTrace();
+        }
+        abacusPluginManager.reload();
 
         changesMade = false;
         reloadAlertShown = false;
@@ -167,29 +201,68 @@ public class AbacusController implements PluginListener {
     }
 
     @FXML
-    private void performCalculation(){
+    private void performCalculation() {
-        inputButton.setDisable(true);
+        Runnable calculator = new Runnable() {
-        TreeNode constructedTree = abacus.parseString(inputField.getText());
+            public void run() {
-        if(constructedTree == null){
+                if (delay > 0) {
-            outputText.setText(ERR_SYNTAX);
+                    Runnable timer = new Runnable() {
-            inputButton.setDisable(false);
+                        public void run() {
-            return;
+                            long gap = (long) (delay * 1000);
-        }
+                            long startTime = System.currentTimeMillis();
-        NumberInterface evaluatedNumber = abacus.evaluateTree(constructedTree);
+                            while (System.currentTimeMillis() - startTime <= gap) {
-        if(evaluatedNumber == null){
+                            }
-            outputText.setText(ERR_EVAL);
+                            stopCalculation();
-            inputButton.setDisable(false);
+                        }
-            return;
+                    };
-        }
+                    Thread maxTime = new Thread(timer);
-        outputText.setText(evaluatedNumber.toString());
+                    maxTime.setName("maxTime");
-        historyData.add(new HistoryModel(inputField.getText(), constructedTree.toString(), evaluatedNumber.toString()));
+                    maxTime.start();
+                }
+                calculating = true;
+                Platform.runLater(() -> inputButton.setDisable(true));
+                TreeNode constructedTree = abacus.parseString(inputField.getText());
+                if (constructedTree == null) {
+                    Platform.runLater(() -> outputText.setText(ERR_SYNTAX));
+                    Platform.runLater(() -> inputButton.setDisable(false));
+                    //return;
+                } else {
+                    NumberInterface evaluatedNumber = abacus.evaluateTree(constructedTree);
+                    if (evaluatedNumber == null) {
+                        if (Thread.currentThread().isInterrupted()) {
+                            Platform.runLater(() -> outputText.setText(ERR_STOP));
+                            Platform.runLater(() -> inputButton.setDisable(false));
+                        } else {
+                            Platform.runLater(() -> outputText.setText(ERR_EVAL));
+                            Platform.runLater(() -> inputButton.setDisable(false));
+                            //return;
+                        }
+                    } else {
+                        Platform.runLater(() -> outputText.setText(evaluatedNumber.toString()));
+                        historyData.add(new HistoryModel(inputField.getText(), constructedTree.toString(), evaluatedNumber.toString()));
 
-        inputButton.setDisable(false);
+                        Platform.runLater(() -> inputButton.setDisable(false));
-        inputField.setText("");
+                        Platform.runLater(() -> inputField.setText(""));
+                    }
+                }
+                calculating = false;
+            }
+        };
+        if (!calculating) {
+            calcThread = new Thread(calculator);
+            calcThread.setName("calcThread");
+            calcThread.start();
+        }
     }
 
     @FXML
-    private void performSaveAndReload(){
+    private void stopCalculation() {
+        calcThread.interrupt();
+        calculating = false;
+        //Platform.runLater(() ->inputButton.setDisable(false));
+    }
+
+    @FXML
+    private void performSaveAndReload() {
         performSave();
         performReload();
         changesMade = false;
@@ -197,21 +270,21 @@ public class AbacusController implements PluginListener {
     }
 
     @FXML
-    private void performReload(){
+    private void performReload() {
         alertIfApplyNeeded(true);
         abacus.getPluginManager().reload();
     }
 
     @FXML
-    private void performSave(){
+    private void performSave() {
         Configuration configuration = abacus.getConfiguration();
         configuration.setNumberImplementation(numberImplementationBox.getSelectionModel().getSelectedItem());
         Set<String> disabledPlugins = configuration.getDisabledPlugins();
         disabledPlugins.clear();
-        for(ToggleablePlugin pluginEntry : enabledPlugins){
+        for (ToggleablePlugin pluginEntry : enabledPlugins) {
-            if(!pluginEntry.isEnabled()) disabledPlugins.add(pluginEntry.getClassName());
+            if (!pluginEntry.isEnabled()) disabledPlugins.add(pluginEntry.getClassName());
         }
-        configuration.saveTo(Abacus.CONFIG_FILE);
+        configuration.saveTo(CONFIG_FILE);
         changesMade = false;
         reloadAlertShown = false;
     }
@@ -220,11 +293,11 @@ public class AbacusController implements PluginListener {
     public void onLoad(PluginManager manager) {
         Configuration configuration = abacus.getConfiguration();
         Set<String> disabledPlugins = configuration.getDisabledPlugins();
-        numberImplementationOptions.addAll(abacus.getPluginManager().getAllNumbers());
+        numberImplementationOptions.addAll(abacus.getPluginManager().getAllNumberImplementations());
         String actualImplementation = configuration.getNumberImplementation();
         String toSelect = (numberImplementationOptions.contains(actualImplementation)) ? actualImplementation : "<default>";
         numberImplementationBox.getSelectionModel().select(toSelect);
-        for(Class<?> pluginClass : abacus.getPluginManager().getLoadedPluginClasses()){
+        for (Class<?> pluginClass : abacus.getPluginManager().getLoadedPluginClasses()) {
             String fullName = pluginClass.getName();
             ToggleablePlugin plugin = new ToggleablePlugin(!disabledPlugins.contains(fullName), fullName);
             plugin.enabledProperty().addListener(e -> changesMade = true);

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

@@ -9,6 +9,7 @@ import java.awt.datatransfer.StringSelection;
 /**
  * A cell that copies its value to the clipboard
  * when double clicked.
+ *
  * @param <S> The type of the table view generic type.
  * @param <T> The type of the value contained in the cell.
  */
@@ -17,9 +18,9 @@ public class CopyableCell<S, T> extends TableCell<S, T> {
     /**
      * Creates a new copyable cell.
      */
-    public CopyableCell(){
+    public CopyableCell() {
         addEventFilter(MouseEvent.MOUSE_CLICKED, event -> {
-            if(event.getClickCount() == 2){
+            if (event.getClickCount() == 2) {
                 Toolkit.getDefaultToolkit().getSystemClipboard()
                         .setContents(new StringSelection(getText()), null);
             }

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

@@ -26,11 +26,12 @@ public class HistoryModel {
 
     /**
      * Creates a new history model with the given variables.
-     * @param input the user input
+     *
+     * @param input  the user input
      * @param parsed the parsed input
      * @param output the program output.
      */
-    public HistoryModel(String input, String parsed, String output){
+    public HistoryModel(String input, String parsed, String output) {
         this.input = new SimpleStringProperty();
         this.parsed = new SimpleStringProperty();
         this.output = new SimpleStringProperty();
@@ -41,13 +42,16 @@ public class HistoryModel {
 
     /**
      * Gets the input property.
+     *
      * @return the input property.
      */
     public StringProperty inputProperty() {
         return input;
     }
+
     /**
      * Gets the input.
+     *
      * @return the input.
      */
     public String getInput() {
@@ -56,13 +60,16 @@ public class HistoryModel {
 
     /**
      * 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() {
@@ -71,13 +78,16 @@ public class HistoryModel {
 
     /**
      * Gets the output property.
+     *
      * @return the output property.
      */
     public StringProperty outputProperty() {
         return output;
     }
+
     /**
      * Gets the program output.
+     *
      * @return the output.
      */
     public String getOutput() {

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

@@ -3,25 +3,56 @@ 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;
 
-    public ToggleablePlugin(boolean enabled, 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

@@ -26,6 +26,7 @@ public class NaiveNumber implements NumberInterface {
     public NaiveNumber(String value) {
         this(Double.parseDouble(value));
     }
+
     /**
      * Creates a new NaiveNumber with the given value.
      *
@@ -94,8 +95,23 @@ public class NaiveNumber implements NumberInterface {
     }
 
     @Override
-    public int ceiling() {
+    public NumberInterface ceiling() {
-        return (int) Math.ceil(value);
+        return new NaiveNumber(Math.ceil(value));
+    }
+
+    @Override
+    public NumberInterface floor() {
+        return new NaiveNumber(Math.floor(value));
+    }
+
+    @Override
+    public NumberInterface fractionalPart() {
+        return new NaiveNumber(value - Math.floor(value));
+    }
+
+    @Override
+    public int intValue() {
+        return (int) value;
     }
 
     @Override

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

@@ -81,9 +81,32 @@ public interface NumberInterface {
 
     /**
      * Returns the least integer greater than or equal to the number.
+     *
      * @return the least integer >= the number, if int can hold the value.
      */
-    int ceiling();
+    NumberInterface ceiling();
+
+    /**
+     * Return the greatest integer less than or equal to the number.
+     *
+     * @return the greatest int >= the number, if int can hold the value.
+     */
+    NumberInterface floor();
+
+    /**
+     * Returns the fractional part of the number.
+     *
+     * @return the fractional part of the number.
+     */
+    NumberInterface fractionalPart();
+
+    /**
+     * Returns the integer representation of this number, discarding any fractional part,
+     * if int can hold the value.
+     *
+     * @return
+     */
+    int intValue();
 
     /**
      * Promotes this class to another number class.

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

@@ -12,15 +12,15 @@ public class PreciseNumber implements NumberInterface {
     /**
      * The number one.
      */
-    static final PreciseNumber ONE = new PreciseNumber(BigDecimal.ONE);
+    public static final PreciseNumber ONE = new PreciseNumber(BigDecimal.ONE);
     /**
      * The number zero.
      */
-    static final PreciseNumber ZERO = new PreciseNumber(BigDecimal.ZERO);
+    public static final PreciseNumber ZERO = new PreciseNumber(BigDecimal.ZERO);
     /**
      * The number ten.
      */
-    static final PreciseNumber TEN = new PreciseNumber(BigDecimal.TEN);
+    public static final PreciseNumber TEN = new PreciseNumber(BigDecimal.TEN);
 
     /**
      * The value of the PreciseNumber.
@@ -99,8 +99,38 @@ public class PreciseNumber implements NumberInterface {
     }
 
     @Override
-    public int ceiling() {
+    public NumberInterface ceiling() {
-        return (int) Math.ceil(value.doubleValue());
+        String str = value.toPlainString();
+        int decimalIndex = str.indexOf('.');
+        if (decimalIndex != -1) {
+            return this.floor().add(ONE);
+        }
+        return this;
+    }
+
+    @Override
+    public NumberInterface floor() {
+        String str = value.toPlainString();
+        int decimalIndex = str.indexOf('.');
+        if (decimalIndex != -1) {
+            return new PreciseNumber(str.substring(0, decimalIndex));
+        }
+        return this;
+    }
+
+    @Override
+    public NumberInterface fractionalPart() {
+        String str = value.toPlainString();
+        int decimalIndex = str.indexOf('.');
+        if (decimalIndex != -1) {
+            return new PreciseNumber(str.substring(decimalIndex + 1));
+        }
+        return ZERO;
+    }
+
+    @Override
+    public int intValue() {
+        return value.intValue();
     }
 
     @Override

src/main/java/org/nwapw/abacus/parsing/ShuntingYardParser.java

@@ -77,8 +77,8 @@ public class ShuntingYardParser implements Parser<Match<TokenType>>, PluginListe
                     continue;
                 }
 
-                if(tokenString.equals("-") && (previousType == null || previousType == TokenType.OP ||
+                if (tokenString.equals("-") && (previousType == null || previousType == TokenType.OP ||
-                        previousType == TokenType.OPEN_PARENTH)){
+                        previousType == TokenType.OPEN_PARENTH)) {
                     from.add(0, new Match<>("`", TokenType.OP));
                     continue;
                 }

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

@@ -0,0 +1,81 @@
+package org.nwapw.abacus.plugin;
+
+import org.nwapw.abacus.number.NumberInterface;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.function.Function;
+
+/**
+ * A class that holds data about a number implementation.
+ */
+public abstract class NumberImplementation {
+
+    /**
+     * The list of paths through which this implementation can be promoted.
+     */
+    protected Map<Class<? extends NumberInterface>, Function<NumberInterface, NumberInterface>> promotionPaths;
+    /**
+     * The implementation class for this implementation.
+     */
+    private Class<? extends NumberInterface> implementation;
+    /**
+     * The priority of converting into this number implementation.
+     */
+    private int priority;
+
+    /**
+     * Creates a new number implementation with the given data.
+     *
+     * @param implementation the implementation class.
+     * @param priority       the priority, higher -> more likely to be converted into.
+     */
+    public NumberImplementation(Class<? extends NumberInterface> implementation, int priority) {
+        this.implementation = implementation;
+        this.priority = priority;
+        promotionPaths = new HashMap<>();
+    }
+
+    /**
+     * Gets the list of all promotion paths this implementation can take.
+     *
+     * @return the map of documentation paths.
+     */
+    public final Map<Class<? extends NumberInterface>, Function<NumberInterface, NumberInterface>> getPromotionPaths() {
+        return promotionPaths;
+    }
+
+    /**
+     * Gets the implementation class used by this implementation.
+     *
+     * @return the implementation class.
+     */
+    public final Class<? extends NumberInterface> getImplementation() {
+        return implementation;
+    }
+
+    /**
+     * Gets the priority of this number implementation.
+     *
+     * @return the priority.
+     */
+    public final int getPriority() {
+        return priority;
+    }
+
+    /**
+     * Abstract function to create a new instance from a string.
+     *
+     * @param string the string to create a number from.
+     * @return the resulting number.
+     */
+    public abstract NumberInterface instanceForString(String string);
+
+    /**
+     * Get the instance of pi with the given implementation.
+     *
+     * @return pi
+     */
+    public abstract NumberInterface instanceForPi();
+
+}

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

@@ -26,9 +26,9 @@ public abstract class Plugin {
      */
     private Map<String, Operator> operators;
     /**
-     * A hash map of operators mapped to their string names.
+     * The map of the number implementations this plugin provides.
      */
-    private Map<String, Class<? extends NumberInterface>> numbers;
+    private Map<String, NumberImplementation> numberImplementations;
     /**
      * The plugin manager in which to search for functions
      * not inside this package,
@@ -51,7 +51,7 @@ public abstract class Plugin {
         this.manager = manager;
         functions = new HashMap<>();
         operators = new HashMap<>();
-        numbers = new HashMap<>();
+        numberImplementations = new HashMap<>();
         enabled = false;
     }
 
@@ -74,12 +74,12 @@ public abstract class Plugin {
     }
 
     /**
-     * Gets the list of all numbers provided by this plugin.
+     * Gets the list of number implementations provided by this plugin.
      *
-     * @return the list of registered numbers.
+     * @return the list of registered number implementations.
      */
-    public final Set<String> providedNumbers() {
+    public final Set<String> providedNumberImplementations() {
-        return numbers.keySet();
+        return numberImplementations.keySet();
     }
 
     /**
@@ -103,13 +103,13 @@ public abstract class Plugin {
     }
 
     /**
-     * Gets the class under the given name.
+     * Gets the number implementation under the given name.
      *
-     * @param numberName the name of the class.
+     * @param name the name of the number implementation to look up.
-     * @return the class, or null if the plugin doesn't provide it.
+     * @return the number implementation associated with that name, or null if the plugin doesn't provide it.
      */
-    public final Class<? extends NumberInterface> getNumber(String numberName) {
+    public final NumberImplementation getNumberImplementation(String name) {
-        return numbers.get(numberName);
+        return numberImplementations.get(name);
     }
 
     /**
@@ -158,16 +158,14 @@ public abstract class Plugin {
     }
 
     /**
-     * To be used in load(). Registers a number class
+     * To be used in load(). Registers a new number implementation with the plugin.
-     * with the plugin internally, which makes it possible
+     * This makes it accessible to the plugin manager.
-     * for the user to select it as an "implementation" for the
-     * number that they would like to use.
      *
-     * @param name       the name to register it under.
+     * @param name           the name of the implementation.
-     * @param toRegister the class to register.
+     * @param implementation the actual implementation class to register.
      */
-    protected final void registerNumber(String name, Class<? extends NumberInterface> toRegister) {
+    protected final void registerNumberImplementation(String name, NumberImplementation implementation) {
-        numbers.put(name, toRegister);
+        numberImplementations.put(name, implementation);
     }
 
     /**
@@ -194,6 +192,31 @@ public abstract class Plugin {
         return manager.operatorFor(name);
     }
 
+    /**
+     * Searches the PluginManager for the given number implementation
+     * name. This can be used by the plugins internally in order to find
+     * implementations that they do not provide.
+     *
+     * @param name the name for which to search.
+     * @return the resulting number implementation, or null if none was found.
+     */
+    protected final NumberImplementation numberImplementationFor(String name) {
+        return manager.numberImplementationFor(name);
+    }
+
+    /**
+     * Searches the plugin manager for a Pi value for the given number implementation.
+     * This is done so that number implementations with various degrees of precision
+     * can provide their own pi values, without losing said precision by
+     * promoting NaiveNumbers.
+     *
+     * @param forClass the class to which to find the pi instance.
+     * @return the pi value for the given class.
+     */
+    protected final NumberInterface getPi(Class<? extends NumberInterface> forClass) {
+        return manager.piFor(forClass);
+    }
+
     /**
      * Abstract method to be overridden by plugin implementation, in which the plugins
      * are supposed to register the functions they provide and do any other

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

@@ -33,10 +33,19 @@ public class PluginManager {
      */
     private Map<String, Operator> cachedOperators;
     /**
-     * List of registered number implementations that have
+     * The list of number implementations that have
      * been cached, that is, found in a plugin and returned.
      */
-    private Map<String, Class<? extends NumberInterface>> cachedNumbers;
+    private Map<String, NumberImplementation> cachedNumberImplementations;
+    /**
+     * The list of number implementations that have been
+     * found by their implementation class.
+     */
+    private Map<Class<? extends NumberInterface>, NumberImplementation> cachedInterfaceImplementations;
+    /**
+     * The pi values for each implementation class that have already been computer.
+     */
+    private Map<Class<? extends NumberInterface>, NumberInterface> cachedPi;
     /**
      * List of all functions loaded by the plugins.
      */
@@ -46,9 +55,9 @@ public class PluginManager {
      */
     private Set<String> allOperators;
     /**
-     * List of all numbers loaded by the plugins.
+     * List of all the number implementations loaded by the plugins.
      */
-    private Set<String> allNumbers;
+    private Set<String> allNumberImplementations;
     /**
      * The list of plugin listeners attached to this instance.
      */
@@ -68,10 +77,12 @@ public class PluginManager {
         plugins = new HashSet<>();
         cachedFunctions = new HashMap<>();
         cachedOperators = new HashMap<>();
-        cachedNumbers = new HashMap<>();
+        cachedNumberImplementations = new HashMap<>();
+        cachedInterfaceImplementations = new HashMap<>();
+        cachedPi = new HashMap<>();
         allFunctions = new HashSet<>();
         allOperators = new HashSet<>();
-        allNumbers = new HashSet<>();
+        allNumberImplementations = new HashSet<>();
         listeners = new HashSet<>();
     }
 
@@ -87,12 +98,13 @@ public class PluginManager {
      * @param getFunction the function to get the T value under the given name
      * @param name        the name to search for
      * @param <T>         the type of element being search
+     * @param <K>         the type of key that the cache is indexed by.
      * @return the retrieved element, or null if it was not found.
      */
-    private static <T> T searchCached(Collection<Plugin> plugins, Map<String, T> cache,
+    private static <T, K> T searchCached(Collection<Plugin> plugins, Map<K, T> cache,
-                                      java.util.function.Function<Plugin, Set<String>> setFunction,
+                                         java.util.function.Function<Plugin, Set<K>> setFunction,
-                                      java.util.function.BiFunction<Plugin, String, T> getFunction,
+                                         java.util.function.BiFunction<Plugin, K, T> getFunction,
-                                      String name) {
+                                         K name) {
         if (cache.containsKey(name)) return cache.get(name);
 
         T loadedValue = null;
@@ -128,13 +140,54 @@ public class PluginManager {
     }
 
     /**
-     * Gets a numer implementation under the given name.
+     * Gets the number implementation under the given name.
      *
      * @param name the name of the implementation.
-     * @return the implementation class
+     * @return the implementation.
      */
-    public Class<? extends NumberInterface> numberFor(String name) {
+    public NumberImplementation numberImplementationFor(String name) {
-        return searchCached(plugins, cachedNumbers, Plugin::providedNumbers, Plugin::getNumber, name);
+        return searchCached(plugins, cachedNumberImplementations, Plugin::providedNumberImplementations,
+                Plugin::getNumberImplementation, name);
+    }
+
+    /**
+     * Gets the number implementation for the given implementation class.
+     *
+     * @param name the class for which to find the implementation.
+     * @return the implementation.
+     */
+    public NumberImplementation interfaceImplementationFor(Class<? extends NumberInterface> name) {
+        if (cachedInterfaceImplementations.containsKey(name)) return cachedInterfaceImplementations.get(name);
+        NumberImplementation toReturn = null;
+        outside:
+        for (Plugin plugin : plugins) {
+            for (String implementationName : plugin.providedNumberImplementations()) {
+                NumberImplementation implementation = plugin.getNumberImplementation(implementationName);
+                if (implementation.getImplementation().equals(name)) {
+                    toReturn = implementation;
+                    break outside;
+                }
+            }
+        }
+        cachedInterfaceImplementations.put(name, toReturn);
+        return toReturn;
+    }
+
+    /**
+     * Gets the mathematical constant pi for the given implementation class.
+     *
+     * @param forClass the class for which to find pi.
+     * @return pi
+     */
+    public NumberInterface piFor(Class<? extends NumberInterface> forClass) {
+        if (cachedPi.containsKey(forClass)) return cachedPi.get(forClass);
+        NumberImplementation implementation = interfaceImplementationFor(forClass);
+        NumberInterface generatedPi = null;
+        if (implementation != null) {
+            generatedPi = implementation.instanceForPi();
+        }
+        cachedPi.put(forClass, generatedPi);
+        return generatedPi;
     }
 
     /**
@@ -169,14 +222,14 @@ public class PluginManager {
     public void load() {
         Set<String> disabledPlugins = abacus.getConfiguration().getDisabledPlugins();
         for (Plugin plugin : plugins) {
-            if(disabledPlugins.contains(plugin.getClass().getName())) continue;
+            if (disabledPlugins.contains(plugin.getClass().getName())) continue;
             plugin.enable();
         }
         for (Plugin plugin : plugins) {
-            if(disabledPlugins.contains(plugin.getClass().getName())) continue;
+            if (disabledPlugins.contains(plugin.getClass().getName())) continue;
             allFunctions.addAll(plugin.providedFunctions());
             allOperators.addAll(plugin.providedOperators());
-            allNumbers.addAll(plugin.providedNumbers());
+            allNumberImplementations.addAll(plugin.providedNumberImplementations());
         }
         listeners.forEach(e -> e.onLoad(this));
     }
@@ -188,15 +241,18 @@ public class PluginManager {
         listeners.forEach(e -> e.onUnload(this));
         Set<String> disabledPlugins = abacus.getConfiguration().getDisabledPlugins();
         for (Plugin plugin : plugins) {
-            if(disabledPlugins.contains(plugin.getClass().getName())) continue;
+            if (disabledPlugins.contains(plugin.getClass().getName())) continue;
             plugin.disable();
         }
         cachedFunctions.clear();
         cachedOperators.clear();
-        cachedNumbers.clear();
+        cachedNumberImplementations.clear();
+        cachedInterfaceImplementations.clear();
+        cachedPi.clear();
         allFunctions.clear();
         allOperators.clear();
-        allNumbers.clear();
+        allNumberImplementations.clear();
+        listeners.forEach(e -> e.onUnload(this));
     }
 
     /**
@@ -226,12 +282,12 @@ public class PluginManager {
     }
 
     /**
-     * Gets all the number implementations loaded by the Plugin Manager
+     * Gets all the number implementations loaded by the Plugin Manager.
      *
-     * @return the set of all implementations that were loaded
+     * @return the set of all implementations that were loaded.
      */
-    public Set<String> getAllNumbers() {
+    public Set<String> getAllNumberImplementations() {
-        return allNumbers;
+        return allNumberImplementations;
     }
 
     /**
@@ -255,6 +311,7 @@ public class PluginManager {
     /**
      * Gets a list of all the plugin class files that have been
      * added to the plugin manager.
+     *
      * @return the list of all the added plugin classes.
      */
     public Set<Class<?>> getLoadedPluginClasses() {

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

@@ -18,8 +18,6 @@ import java.util.function.BiFunction;
  */
 public class StandardPlugin extends Plugin {
 
-    private static HashMap<Class<? extends NumberInterface>, ArrayList<NumberInterface>> factorialLists = new HashMap<Class<? extends NumberInterface>, ArrayList<NumberInterface>>();
-
     /**
      * The addition operator, +
      */
@@ -31,9 +29,13 @@ public class StandardPlugin extends Plugin {
 
         @Override
         protected NumberInterface applyInternal(NumberInterface[] params) {
+            if (Thread.currentThread().isInterrupted())
+                return null;
             NumberInterface sum = params[0];
             for (int i = 1; i < params.length; i++) {
                 sum = sum.add(params[i]);
+                if (Thread.currentThread().isInterrupted())
+                    return null;
             }
             return sum;
         }
@@ -49,7 +51,10 @@ public class StandardPlugin extends Plugin {
 
         @Override
         protected NumberInterface applyInternal(NumberInterface[] params) {
+            if (Thread.currentThread().isInterrupted())
+                return null;
             return params[0].subtract(params[1]);
+
         }
     });
     /**
@@ -63,6 +68,8 @@ public class StandardPlugin extends Plugin {
 
         @Override
         protected NumberInterface applyInternal(NumberInterface[] params) {
+            if (Thread.currentThread().isInterrupted())
+                return null;
             return params[0].negate();
         }
     });
@@ -77,9 +84,13 @@ public class StandardPlugin extends Plugin {
 
         @Override
         protected NumberInterface applyInternal(NumberInterface[] params) {
+            if (Thread.currentThread().isInterrupted())
+                return null;
             NumberInterface product = params[0];
             for (int i = 1; i < params.length; i++) {
                 product = product.multiply(params[i]);
+                if (Thread.currentThread().isInterrupted())
+                    return null;
             }
             return product;
         }
@@ -90,11 +101,13 @@ public class StandardPlugin extends Plugin {
     public static final Operator OP_DIVIDE = new Operator(OperatorAssociativity.LEFT, OperatorType.BINARY_INFIX, 1, new Function() {
         @Override
         protected boolean matchesParams(NumberInterface[] params) {
-            return params.length == 2;
+            return params.length == 2 && params[1].compareTo(NaiveNumber.ZERO.promoteTo(params[1].getClass())) != 0;
         }
 
         @Override
         protected NumberInterface applyInternal(NumberInterface[] params) {
+            if (Thread.currentThread().isInterrupted())
+                return null;
             return params[0].divide(params[1]);
         }
     });
@@ -105,20 +118,26 @@ public class StandardPlugin extends Plugin {
         //private HashMap<Class<? extends NumberInterface>, ArrayList<NumberInterface>> storedList = new HashMap<Class<? extends NumberInterface>, ArrayList<NumberInterface>>();
         @Override
         protected boolean matchesParams(NumberInterface[] params) {
-            return params.length == 1;
+            return params.length == 1
+                    && params[0].fractionalPart().compareTo(NaiveNumber.ZERO.promoteTo(params[0].getClass())) == 0
+                    && params[0].signum() >= 0;
         }
 
         @Override
         protected NumberInterface applyInternal(NumberInterface[] params) {
+            if (Thread.currentThread().isInterrupted())
+                return null;
             if (params[0].signum() == 0) {
                 return (new NaiveNumber(1)).promoteTo(params[0].getClass());
             }
             NumberInterface factorial = params[0];
             NumberInterface multiplier = params[0];
             //It is necessary to later prevent calls of factorial on anything but non-negative integers.
-            while ((multiplier = multiplier.subtract(NaiveNumber.ONE.promoteTo(multiplier.getClass()))).signum() == 1) {
+            while (!Thread.currentThread().isInterrupted() && (multiplier = multiplier.subtract(NaiveNumber.ONE.promoteTo(multiplier.getClass()))) != null && multiplier.signum() == 1) {
                 factorial = factorial.multiply(multiplier);
             }
+            if (Thread.currentThread().isInterrupted())
+                return null;
             return factorial;
                 /*if(!storedList.containsKey(params[0].getClass())){
                     storedList.put(params[0].getClass(), new ArrayList<NumberInterface>());
@@ -127,20 +146,6 @@ public class StandardPlugin extends Plugin {
                 }*/
         }
     });
-    /**
-     * The caret / pow operator, ^
-     */
-    public static final Operator OP_CARET = new Operator(OperatorAssociativity.RIGHT, OperatorType.BINARY_INFIX, 2, new Function() {
-        @Override
-        protected boolean matchesParams(NumberInterface[] params) {
-            return params.length == 2;
-        }
-
-        @Override
-        protected NumberInterface applyInternal(NumberInterface[] params) {
-            return FUNCTION_EXP.apply(FUNCTION_LN.apply(params[0]).multiply(params[1]));
-        }
-    });
     /**
      * The absolute value function, abs(-3) = 3
      */
@@ -152,83 +157,48 @@ public class StandardPlugin extends Plugin {
 
         @Override
         protected NumberInterface applyInternal(NumberInterface[] params) {
+            if (Thread.currentThread().isInterrupted())
+                return null;
             return params[0].multiply((new NaiveNumber(params[0].signum())).promoteTo(params[0].getClass()));
         }
     };
-    /**
-     * The exponential function, exp(1) = e^1 = 2.71...
-     */
-    public static final Function FUNCTION_EXP = new Function() {
-        @Override
-        protected boolean matchesParams(NumberInterface[] params) {
-            return params.length == 1;
-        }
-
-        @Override
-        protected NumberInterface applyInternal(NumberInterface[] params) {
-            NumberInterface maxError = getMaxError(params[0]);
-            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;
-            }
-            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.
-                NumberInterface sum = NaiveNumber.ONE.promoteTo(params[0].getClass());
-                NumberInterface nextNumerator = params[0];
-                NumberInterface left = params[0].multiply((new NaiveNumber(3)).promoteTo(params[0].getClass()).intPow(params[0].ceiling())), right = maxError;
-                do{
-                    sum = sum.add(nextNumerator.divide(factorial(params[0].getClass(), n+1)));
-                    n++;
-                    nextNumerator = nextNumerator.multiply(params[0]);
-                    left = left.multiply(params[0]);
-                    NumberInterface nextN = (new NaiveNumber(n+1)).promoteTo(params[0].getClass());
-                    right = right.multiply(nextN);
-                    //System.out.println(left + ", " + right);
-                }
-                while(left.compareTo(right) > 0);
-                //System.out.println(n+1);
-                return sum;
-            }
-        }
-    };
     /**
      * The natural log function.
      */
     public static final Function FUNCTION_LN = new Function() {
         @Override
         protected boolean matchesParams(NumberInterface[] params) {
-            return params.length == 1;
+            return params.length == 1 && params[0].compareTo(NaiveNumber.ZERO.promoteTo(params[0].getClass())) > 0;
         }
 
         @Override
         protected NumberInterface applyInternal(NumberInterface[] params) {
+            if (Thread.currentThread().isInterrupted())
+                return null;
             NumberInterface param = params[0];
             int powersOf2 = 0;
-            while (FUNCTION_ABS.apply(param.subtract(NaiveNumber.ONE.promoteTo(param.getClass()))).compareTo((new NaiveNumber(0.1)).promoteTo(param.getClass())) >= 0) {
+            NumberInterface check;
-                if (param.subtract(NaiveNumber.ONE.promoteTo(param.getClass())).signum() == 1) {
+            while (!Thread.currentThread().isInterrupted() && (check = FUNCTION_ABS.apply(param.subtract(NaiveNumber.ONE.promoteTo(param.getClass())))) != null && (check.compareTo((new NaiveNumber(0.1)).promoteTo(param.getClass()))) >= 0) {
+                if ((check = param.subtract(NaiveNumber.ONE.promoteTo(param.getClass()))) != null && check.signum() == 1) {
                     param = param.divide(new NaiveNumber(2).promoteTo(param.getClass()));
                     powersOf2++;
-                    if (param.subtract(NaiveNumber.ONE.promoteTo(param.getClass())).signum() != 1) {
+                    if ((check = param.subtract(NaiveNumber.ONE.promoteTo(param.getClass()))) == null || check.signum() != 1) {
                         break;
                         //No infinite loop for you.
                     }
                 } else {
                     param = param.multiply(new NaiveNumber(2).promoteTo(param.getClass()));
                     powersOf2--;
-                    if (param.subtract(NaiveNumber.ONE.promoteTo(param.getClass())).signum() != -1) {
+                    if ((check = param.subtract(NaiveNumber.ONE.promoteTo(param.getClass()))) == null || check.signum() != 1) {
                         break;
                         //No infinite loop for you.
                     }
                 }
             }
-            return getLog2(param).multiply((new NaiveNumber(powersOf2)).promoteTo(param.getClass())).add(getLogPartialSum(param));
+            NumberInterface check2;
+            if (!Thread.currentThread().isInterrupted() && (check = getLog2(param)) != null && (check = check.multiply((new NaiveNumber(powersOf2).promoteTo(param.getClass())))) != null && (check2 = getLogPartialSum(param)) != null && (check = check.add(check2)) != null)
+                return check;
+            return null;
         }
 
         /**
@@ -238,16 +208,23 @@ public class StandardPlugin extends Plugin {
          * @return the partial sum.
          */
         private NumberInterface getLogPartialSum(NumberInterface x) {
+
+            if (Thread.currentThread().isInterrupted())
+                return null;
             NumberInterface maxError = getMaxError(x);
             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;
-            while (FUNCTION_ABS.apply(currentTerm).compareTo(maxError) > 0) {
+            NumberInterface check;
+            while (!Thread.currentThread().isInterrupted() && (check = FUNCTION_ABS.apply(currentTerm)) != null && check.compareTo(maxError) > 0) {
                 n++;
-                currentNumerator = currentNumerator.multiply(x).negate();
+                if ((currentNumerator = currentNumerator.multiply(x)) == null || (currentNumerator = currentNumerator.negate()) == null)
+                    return null;
                 currentTerm = currentNumerator.divide(new NaiveNumber(n).promoteTo(x.getClass()));
                 sum = sum.add(currentTerm);
             }
+            if (Thread.currentThread().isInterrupted())
+                return null;
             return sum;
         }
 
@@ -257,6 +234,8 @@ public class StandardPlugin extends Plugin {
          * @return the value of log(2) with the appropriate precision.
          */
         private NumberInterface getLog2(NumberInterface number) {
+            if (Thread.currentThread().isInterrupted())
+                return null;
             NumberInterface maxError = getMaxError(number);
             //NumberInterface errorBound = (new NaiveNumber(1)).promoteTo(number.getClass());
             //We'll use the series \sigma_{n >= 1) ((1/3^n + 1/4^n) * 1/n)
@@ -265,13 +244,17 @@ public class StandardPlugin extends Plugin {
             NumberInterface a = (new NaiveNumber(1)).promoteTo(number.getClass()), b = a, c = a;
             NumberInterface sum = NaiveNumber.ZERO.promoteTo(number.getClass());
             int n = 0;
-            while (a.compareTo(maxError) >= 1) {
+            while (!Thread.currentThread().isInterrupted() && a.compareTo(maxError) >= 1) {
                 n++;
                 a = a.divide((new NaiveNumber(3)).promoteTo(number.getClass()));
                 b = b.divide((new NaiveNumber(4)).promoteTo(number.getClass()));
                 c = NaiveNumber.ONE.promoteTo(number.getClass()).divide((new NaiveNumber(n)).promoteTo(number.getClass()));
-                sum = sum.add(a.add(b).multiply(c));
+                NumberInterface check;
+                if (a == null || (check = a.add(b)) == null || (check = check.multiply(c)) == null || (sum = sum.add(check)) == null)
+                    return null;
             }
+            if (Thread.currentThread().isInterrupted())
+                return null;
             return sum;
         }
     };
@@ -289,6 +272,218 @@ public class StandardPlugin extends Plugin {
             return OP_CARET.getFunction().apply(params[0], ((new NaiveNumber(0.5)).promoteTo(params[0].getClass())));
         }
     };
+    /**
+     * The implementation for double-based naive numbers.
+     */
+    public static final NumberImplementation IMPLEMENTATION_NAIVE = new NumberImplementation(NaiveNumber.class, 0) {
+        @Override
+        public NumberInterface instanceForString(String string) {
+            return new NaiveNumber(string);
+        }
+
+        @Override
+        public NumberInterface instanceForPi() {
+            return new NaiveNumber(Math.PI);
+        }
+    };
+    /**
+     * The implementation for the infinite-precision BigDecimal.
+     */
+    public static final NumberImplementation IMPLEMENTATION_PRECISE = new NumberImplementation(PreciseNumber.class, 0) {
+        @Override
+        public NumberInterface instanceForString(String string) {
+            return new PreciseNumber(string);
+        }
+
+        @Override
+        public NumberInterface instanceForPi() {
+            NumberInterface C = FUNCTION_SQRT.apply(new PreciseNumber("10005")).multiply(new PreciseNumber("426880"));
+            NumberInterface M = PreciseNumber.ONE;
+            NumberInterface L = new PreciseNumber("13591409");
+            NumberInterface X = M;
+            NumberInterface sum = L;
+            int termsNeeded = C.getMaxPrecision() / 13 + 1;
+
+            NumberInterface lSummand = new PreciseNumber("545140134");
+            NumberInterface xMultiplier = new PreciseNumber("262537412")
+                    .multiply(new PreciseNumber("1000000000"))
+                    .add(new PreciseNumber("640768000"))
+                    .negate();
+            for (int i = 0; i < termsNeeded; i++) {
+                M = M
+                        .multiply(new NaiveNumber(12 * i + 2).promoteTo(PreciseNumber.class))
+                        .multiply(new NaiveNumber(12 * i + 6).promoteTo(PreciseNumber.class))
+                        .multiply(new NaiveNumber(12 * i + 10).promoteTo(PreciseNumber.class))
+                        .divide(new NaiveNumber(Math.pow(i + 1, 3)).promoteTo(PreciseNumber.class));
+                L = L.add(lSummand);
+                X = X.multiply(xMultiplier);
+                sum = sum.add(M.multiply(L).divide(X));
+            }
+            return C.divide(sum);
+        }
+    };
+    private static final HashMap<Class<? extends NumberInterface>, ArrayList<NumberInterface>> FACTORIAL_LISTS = new HashMap<>();
+    /**
+     * The exponential function, exp(1) = e^1 = 2.71...
+     */
+    public static final Function FUNCTION_EXP = new Function() {
+        @Override
+        protected boolean matchesParams(NumberInterface[] params) {
+            return params.length == 1;
+        }
+
+        @Override
+        protected NumberInterface applyInternal(NumberInterface[] params) {
+            NumberInterface maxError = getMaxError(params[0]);
+            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;
+            } 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.
+                NumberInterface sum = NaiveNumber.ONE.promoteTo(params[0].getClass());
+                NumberInterface nextNumerator = params[0];
+                NumberInterface left = params[0].multiply((new NaiveNumber(3)).promoteTo(params[0].getClass()).intPow(params[0].ceiling().intValue())), right = maxError;
+                do {
+                    sum = sum.add(nextNumerator.divide(factorial(params[0].getClass(), n + 1)));
+                    n++;
+                    nextNumerator = nextNumerator.multiply(params[0]);
+                    left = left.multiply(params[0]);
+                    NumberInterface nextN = (new NaiveNumber(n + 1)).promoteTo(params[0].getClass());
+                    right = right.multiply(nextN);
+                    //System.out.println(left + ", " + right);
+                }
+                while (left.compareTo(right) > 0);
+                //System.out.println(n+1);
+                return sum;
+            }
+        }
+    };
+    /**
+     * The caret / pow operator, ^
+     */
+    public static final Operator OP_CARET = new Operator(OperatorAssociativity.RIGHT, OperatorType.BINARY_INFIX, 2, new Function() {
+        @Override
+        protected boolean matchesParams(NumberInterface[] params) {
+            return params.length == 2
+                    && !(params[0].compareTo(NaiveNumber.ZERO.promoteTo(params[0].getClass())) == 0
+                    && params[1].compareTo(NaiveNumber.ZERO.promoteTo(params[1].getClass())) == 0);
+        }
+
+        @Override
+        protected NumberInterface applyInternal(NumberInterface[] params) {
+            if (Thread.currentThread().isInterrupted()) return null;
+            else if (params[0].compareTo(NaiveNumber.ZERO.promoteTo(params[0].getClass())) == 0)
+                return NaiveNumber.ZERO.promoteTo(params[0].getClass());
+            else if (params[1].compareTo(NaiveNumber.ZERO.promoteTo(params[0].getClass())) == 0)
+                return NaiveNumber.ONE.promoteTo(params[1].getClass());
+            FUNCTION_EXP.apply(FUNCTION_LN.apply(FUNCTION_ABS.apply(params[0])).multiply(params[1]));
+            NumberInterface check = FUNCTION_LN.apply(FUNCTION_ABS.apply(params[0]));
+            if(check == null) return null;
+            return FUNCTION_EXP.apply(check.multiply(params[1]));
+        }
+    });
+    /**
+     * The sine function (the argument is interpreted in radians).
+     */
+    public final Function functionSin = new Function() {
+        @Override
+        protected boolean matchesParams(NumberInterface[] params) {
+            return params.length == 1;
+        }
+
+        @Override
+        protected NumberInterface applyInternal(NumberInterface[] params) {
+            NumberInterface pi = getPi(params[0].getClass());
+            NumberInterface twoPi = pi.multiply(new NaiveNumber(2).promoteTo(pi.getClass()));
+            NumberInterface theta = getSmallAngle(params[0], pi);
+            //System.out.println(theta);
+            if (theta.compareTo(pi.multiply(new NaiveNumber(1.5).promoteTo(twoPi.getClass()))) >= 0) {
+                theta = theta.subtract(twoPi);
+            } else if (theta.compareTo(pi.divide(new NaiveNumber(2).promoteTo(pi.getClass()))) > 0) {
+                theta = pi.subtract(theta);
+            }
+            //System.out.println(theta);
+            return sinTaylor(theta);
+        }
+    };
+    /**
+     * The cosine function (the argument is in radians).
+     */
+    public final Function functionCos = new Function() {
+        @Override
+        protected boolean matchesParams(NumberInterface[] params) {
+            return params.length == 1;
+        }
+
+        @Override
+        protected NumberInterface applyInternal(NumberInterface[] params) {
+            return functionSin.apply(getPi(params[0].getClass()).divide(new NaiveNumber(2).promoteTo(params[0].getClass()))
+                    .subtract(params[0]));
+        }
+    };
+    /**
+     * The tangent function (the argument is in radians).
+     */
+    public final Function functionTan = new Function() {
+        @Override
+        protected boolean matchesParams(NumberInterface[] params) {
+            return params.length == 1;
+        }
+
+        @Override
+        protected NumberInterface applyInternal(NumberInterface[] params) {
+            return functionSin.apply(params[0]).divide(functionCos.apply(params[0]));
+        }
+    };
+    /**
+     * The secant function (the argument is in radians).
+     */
+    public final Function functionSec = new Function() {
+        @Override
+        protected boolean matchesParams(NumberInterface[] params) {
+            return params.length == 1;
+        }
+
+        @Override
+        protected NumberInterface applyInternal(NumberInterface[] params) {
+            return NaiveNumber.ONE.promoteTo(params[0].getClass()).divide(functionCos.apply(params[0]));
+        }
+    };
+    /**
+     * The cosecant function (the argument is in radians).
+     */
+    public final Function functionCsc = new Function() {
+        @Override
+        protected boolean matchesParams(NumberInterface[] params) {
+            return params.length == 1;
+        }
+
+        @Override
+        protected NumberInterface applyInternal(NumberInterface[] params) {
+            return NaiveNumber.ONE.promoteTo(params[0].getClass()).divide(functionSin.apply(params[0]));
+        }
+    };
+    /**
+     * The cotangent function (the argument is in radians).
+     */
+    public final Function functionCot = new Function() {
+        @Override
+        protected boolean matchesParams(NumberInterface[] params) {
+            return params.length == 1;
+        }
+
+        @Override
+        protected NumberInterface applyInternal(NumberInterface[] params) {
+            return functionCos.apply(params[0]).divide(functionCos.apply(params[0]));
+        }
+    };
 
     public StandardPlugin(PluginManager manager) {
         super(manager);
@@ -320,10 +515,94 @@ public class StandardPlugin extends Plugin {
         return (new NaiveNumber(10)).promoteTo(number.getClass()).intPow(-number.getMaxPrecision());
     }
 
+    /**
+     * A factorial function that uses memoization for each number class; it efficiently
+     * computes factorials of non-negative integers.
+     *
+     * @param numberClass type of number to return.
+     * @param n           non-negative integer.
+     * @return a number of numClass with value n factorial.
+     */
+    public static NumberInterface factorial(Class<? extends NumberInterface> numberClass, int n) {
+        if (Thread.currentThread().isInterrupted())
+            return null;
+        if (!FACTORIAL_LISTS.containsKey(numberClass)) {
+            FACTORIAL_LISTS.put(numberClass, new ArrayList<>());
+            FACTORIAL_LISTS.get(numberClass).add(NaiveNumber.ONE.promoteTo(numberClass));
+            FACTORIAL_LISTS.get(numberClass).add(NaiveNumber.ONE.promoteTo(numberClass));
+        }
+        ArrayList<NumberInterface> list = FACTORIAL_LISTS.get(numberClass);
+        if (n >= list.size()) {
+            while (!Thread.currentThread().isInterrupted() && list.size() < n + 16) {
+                list.add(list.get(list.size() - 1).multiply(new NaiveNumber(list.size()).promoteTo(numberClass)));
+            }
+        }
+        if (Thread.currentThread().isInterrupted())
+            return null;
+        return list.get(n);
+    }
+
+    /**
+     * Returns the value of the Taylor series for sin (centered at 0) at x.
+     *
+     * @param x where the series is evaluated.
+     * @return the value of the series
+     */
+    private static NumberInterface sinTaylor(NumberInterface x) {
+        NumberInterface power = x, multiplier = x.multiply(x).negate(), currentTerm = x, sum = x;
+        NumberInterface maxError = getMaxError(x);
+        int n = 1;
+        do {
+            n += 2;
+            power = power.multiply(multiplier);
+            currentTerm = power.divide(factorial(x.getClass(), n));
+            sum = sum.add(currentTerm);
+        } while (FUNCTION_ABS.apply(currentTerm).compareTo(maxError) > 0);
+        return sum;
+    }
+
+    /**
+     * Returns an equivalent angle in the interval [0, 2pi)
+     *
+     * @param phi an angle (in radians).
+     * @return theta in [0, 2pi) that differs from phi by a multiple of 2pi.
+     */
+    private static NumberInterface getSmallAngle(NumberInterface phi, NumberInterface pi) {
+        NumberInterface twoPi = pi.multiply(new NaiveNumber("2").promoteTo(phi.getClass()));
+        NumberInterface theta = FUNCTION_ABS.apply(phi).subtract(twoPi
+                .multiply(FUNCTION_ABS.apply(phi).divide(twoPi).floor())); //Now theta is in [0, 2pi).
+        if (phi.signum() < 0) {
+            theta = twoPi.subtract(theta);
+        }
+        return theta;
+    }
+
+    public static NumberInterface intPow(NumberInterface number, Class<? extends NumberInterface> numberClass, NumberInterface exponent) {
+        if (Thread.currentThread().isInterrupted())
+            return null;
+        if (exponent.compareTo((new NaiveNumber(0)).promoteTo(numberClass)) == 0) {
+            return (new NaiveNumber(1)).promoteTo(numberClass);
+        }
+        boolean takeReciprocal = exponent.compareTo((new NaiveNumber(0)).promoteTo(numberClass)) < 0;
+        exponent = FUNCTION_ABS.apply(exponent);
+        NumberInterface power = number;
+        for (NumberInterface currentExponent = (new NaiveNumber(1)).promoteTo(numberClass); currentExponent.compareTo(exponent) < 0; currentExponent = currentExponent.add((new NaiveNumber(1)).promoteTo(numberClass))) {
+            power = power.multiply(number);
+            if (Thread.currentThread().isInterrupted())
+                return null;
+        }
+        if (takeReciprocal) {
+            power = (new NaiveNumber(1)).promoteTo(numberClass).divide(power);
+        }
+        if (Thread.currentThread().isInterrupted())
+            return null;
+        return power;
+    }
+
     @Override
     public void onEnable() {
-        registerNumber("naive", NaiveNumber.class);
+        registerNumberImplementation("naive", IMPLEMENTATION_NAIVE);
-        registerNumber("precise", PreciseNumber.class);
+        registerNumberImplementation("precise", IMPLEMENTATION_PRECISE);
 
         registerOperator("+", OP_ADD);
         registerOperator("-", OP_SUBTRACT);
@@ -337,26 +616,16 @@ public class StandardPlugin extends Plugin {
         registerFunction("exp", FUNCTION_EXP);
         registerFunction("ln", FUNCTION_LN);
         registerFunction("sqrt", FUNCTION_SQRT);
+        registerFunction("sin", functionSin);
+        registerFunction("cos", functionCos);
+        registerFunction("tan", functionTan);
+        registerFunction("sec", functionSec);
+        registerFunction("csc", functionCsc);
+        registerFunction("cot", functionCot);
     }
 
     @Override
     public void onDisable() {
 
     }
-
-    public static NumberInterface factorial(Class<? extends NumberInterface> numberClass, int n){
-        if(!factorialLists.containsKey(numberClass)){
-            factorialLists.put(numberClass, new ArrayList<>());
-            factorialLists.get(numberClass).add(NaiveNumber.ONE.promoteTo(numberClass));
-            factorialLists.get(numberClass).add(NaiveNumber.ONE.promoteTo(numberClass));
-        }
-        ArrayList<NumberInterface> list = factorialLists.get(numberClass);
-        if(n >= list.size()){
-            while(list.size() < n + 16){
-                list.add(list.get(list.size()-1).multiply(new NaiveNumber(list.size()).promoteTo(numberClass)));
-            }
-        }
-        return list.get(n);
-    }
-
 }

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

@@ -92,10 +92,15 @@ public class BinaryNode extends TreeNode {
 
     @Override
     public <T> T reduce(Reducer<T> reducer) {
+        if (Thread.currentThread().isInterrupted())
+            return null;
         T leftReduce = left.reduce(reducer);
         T rightReduce = right.reduce(reducer);
         if (leftReduce == null || rightReduce == null) return null;
-        return reducer.reduceNode(this, leftReduce, rightReduce);
+        T a = reducer.reduceNode(this, leftReduce, rightReduce);
+        if (Thread.currentThread().isInterrupted())
+            return null;
+        return a;
     }
 
     @Override

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

@@ -62,12 +62,17 @@ public class FunctionNode extends TreeNode {
 
     @Override
     public <T> T reduce(Reducer<T> reducer) {
+        if (Thread.currentThread().isInterrupted())
+            return null;
         Object[] reducedChildren = new Object[children.size()];
         for (int i = 0; i < reducedChildren.length; i++) {
             reducedChildren[i] = children.get(i).reduce(reducer);
-            if (reducedChildren[i] == null) return null;
+            if (Thread.currentThread().isInterrupted() || reducedChildren[i] == null) return null;
         }
-        return reducer.reduceNode(this, reducedChildren);
+        T a = reducer.reduceNode(this, reducedChildren);
+        if (Thread.currentThread().isInterrupted())
+            return null;
+        return a;
     }
 
     @Override

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

@@ -33,9 +33,14 @@ public class UnaryNode extends TreeNode {
 
     @Override
     public <T> T reduce(Reducer<T> reducer) {
+        if (Thread.currentThread().isInterrupted())
+            return null;
         Object reducedChild = applyTo.reduce(reducer);
         if (reducedChild == null) return null;
-        return reducer.reduceNode(this, reducedChild);
+        T a = reducer.reduceNode(this, reducedChild);
+        if (Thread.currentThread().isInterrupted())
+            return null;
+        return a;
     }
 
     /**

src/main/java/org/nwapw/abacus/window/Window.java

@@ -250,6 +250,6 @@ public class Window extends JFrame {
     @Override
     public void setVisible(boolean b) {
         super.setVisible(b);
-        if(b) inputField.requestFocusInWindow();
+        if (b) inputField.requestFocusInWindow();
     }
 }

src/main/resources/abacus.fxml

@@ -2,14 +2,10 @@
 
 <?import javafx.geometry.Insets?>
 <?import javafx.scene.control.*?>
-<?import javafx.scene.layout.BorderPane?>
+<?import javafx.scene.layout.*?>
-<?import javafx.scene.layout.VBox?>
 <?import javafx.scene.text.Text?>
-<?import javafx.scene.layout.HBox?>
+<BorderPane xmlns:fx="http://javafx.com/fxml"
-<?import javafx.scene.layout.GridPane?>
+            xmlns="http://javafx.com/javafx"
-<?import javafx.scene.layout.FlowPane?>
-<BorderPane xmlns="http://javafx.com/javafx"
-            xmlns:fx="http://javafx.com/fxml"
             fx:controller="org.nwapw.abacus.fx.AbacusController">
     <center>
         <TabPane fx:id="coreTabPane">
@@ -38,19 +34,24 @@
                             <TextField fx:id="inputField" onAction="#performCalculation"/>
                             <Button fx:id="inputButton" text="Calculate" maxWidth="Infinity"
                                     onAction="#performCalculation"/>
+                            <Button fx:id="stopButton" text="Stop" maxWidth="Infinity"
+                                    onAction="#stopCalculation"/>
                         </VBox>
                     </bottom>
                 </BorderPane>
             </Tab>
             <Tab fx:id="settingsTab" text="Settings" closable="false">
                 <GridPane hgap="10" vgap="10">
-                    <padding><Insets left="10" right="10" top="10" bottom="10"/></padding>
+                    <padding>
+                        <Insets left="10" right="10" top="10" bottom="10"/>
+                    </padding>
                     <Label text="Number Implementation" GridPane.columnIndex="0" GridPane.rowIndex="0"/>
                     <ComboBox fx:id="numberImplementationBox" GridPane.columnIndex="1" GridPane.rowIndex="0"/>
                     <ListView fx:id="enabledPluginView"
                               GridPane.rowIndex="1" GridPane.columnIndex="0"
                               GridPane.columnSpan="2" maxHeight="100"/>
-                    <FlowPane GridPane.columnIndex="0" GridPane.columnSpan="2" GridPane.rowIndex="2" hgap="10" vgap="10">
+                    <FlowPane GridPane.columnIndex="0" GridPane.columnSpan="2" GridPane.rowIndex="2" hgap="10"
+                              vgap="10">
                         <Button text="Apply" onAction="#performSave"/>
                         <Button text="Reload Plugins" onAction="#performReload"/>
                         <Button text="Apply and Reload" onAction="#performSaveAndReload"/>

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

@@ -0,0 +1,104 @@
+package org.nwapw.abacus.tests;
+
+import org.junit.Assert;
+import org.junit.BeforeClass;
+import org.junit.Test;
+import org.nwapw.abacus.Abacus;
+import org.nwapw.abacus.config.Configuration;
+import org.nwapw.abacus.number.NumberInterface;
+import org.nwapw.abacus.plugin.StandardPlugin;
+import org.nwapw.abacus.tree.TreeNode;
+
+public class CalculationTests {
+
+    private static Abacus abacus = new Abacus(new Configuration("precise", new String[]{}));
+
+    @BeforeClass
+    public static void prepareTests(){
+        abacus.getPluginManager().addInstantiated(new StandardPlugin(abacus.getPluginManager()));
+        abacus.getPluginManager().load();
+    }
+
+    private void testOutput(String input, String parseOutput, String output){
+        TreeNode parsedTree = abacus.parseString(input);
+        Assert.assertNotNull(parsedTree);
+        Assert.assertEquals(parsedTree.toString(), parseOutput);
+        NumberInterface result = abacus.evaluateTree(parsedTree);
+        Assert.assertNotNull(result);
+        Assert.assertTrue(result.toString().startsWith(output));
+    }
+
+    private void testEvalError(String input, String parseOutput){
+        TreeNode parsedTree = abacus.parseString(input);
+        Assert.assertNotNull(parsedTree);
+        Assert.assertEquals(parsedTree.toString(), parseOutput);
+        Assert.assertNull(abacus.evaluateTree(parsedTree));
+    }
+
+    @Test
+    public void testAddition(){
+        testOutput("9.5+10", "(9.5+10)", "19.5");
+    }
+
+    @Test
+    public void testSubtraction(){
+        testOutput("9.5-10", "(9.5-10)", "-0.5");
+    }
+
+    @Test
+    public void testMultiplication(){
+        testOutput("9.5*10", "(9.5*10)", "95");
+    }
+
+    @Test
+    public void testDivision(){
+        testOutput("9.5/2", "(9.5/2)", "4.75");
+    }
+
+    @Test
+    public void testNegation(){
+        testOutput("-9.5", "(9.5)`", "-9.5");
+    }
+
+    @Test
+    public void testFactorial(){
+        testOutput("7!", "(7)!", "5040");
+    }
+
+    @Test
+    public void testAbs(){
+        testOutput("abs(-1)", "abs((1)`)", "1");
+        testOutput("abs(1)", "abs(1)", "1");
+    }
+
+    @Test
+    public void testLn(){
+        testEvalError("ln(-1)", "ln((1)`)");
+        testOutput("ln2", "ln(2)", "0.6931471805599453094172321214581765680755");
+    }
+
+    @Test
+    public void testSqrt(){
+        testOutput("sqrt0", "sqrt(0)", "0");
+        testOutput("sqrt4", "sqrt(4)", "2");
+        testOutput("sqrt2", "sqrt(2)", "1.4142135623730950488016887242096980785696");
+    }
+
+    @Test
+    public void testExp(){
+        testOutput("exp0", "exp(0)", "1");
+        testOutput("exp1", "exp(1)", "2.718281828459045235360287471352662497757247");
+        testOutput("exp300", "exp(300)", "19424263952412559365842088360176992193662086");
+        testOutput("exp300", "exp(300)", "19424263952412559365842088360176992193662086");
+    }
+
+    @Test
+    public void testPow(){
+        testOutput("0^2", "(0^2)", "0");
+        testOutput("2^0", "(2^0)", "1");
+        testOutput("2^1", "(2^1)", "2");
+        testOutput("2^-1", "(2^(1)`)", "0.5");
+        testOutput("2^50", "(2^50)", "112589990684262");
+    }
+
+}

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

@@ -4,6 +4,7 @@ import org.junit.Assert;
 import org.junit.BeforeClass;
 import org.junit.Test;
 import org.nwapw.abacus.Abacus;
+import org.nwapw.abacus.config.Configuration;
 import org.nwapw.abacus.function.Function;
 import org.nwapw.abacus.function.Operator;
 import org.nwapw.abacus.function.OperatorAssociativity;
@@ -18,7 +19,7 @@ import java.util.List;
 
 public class TokenizerTests {
 
-    private static Abacus abacus = new Abacus();
+    private static Abacus abacus = new Abacus(new Configuration("precise", new String[]{}));
     private static LexerTokenizer lexerTokenizer = new LexerTokenizer();
     private static Function subtractFunction = new Function() {
         @Override