Add a save and reload button.

README.md

@@ -5,10 +5,10 @@ Summer project for NWAPW.
 Created by Arthur Drobot, Danila Fedorin and Riley Jones.
 
 ## Project Description
-Abacus is a calculator built with extensibility and usability in mind. It provides a plugin interface, via Java, as Lua provides too difficult to link up to the Java core. The description of the internals of the project can be found on the wiki page.
+Abacus is a calculator built with extensibility and usability in mind. It provides a plugin interface, via Java, as Lua proves too difficult to link up to the Java core. The description of the internals of the project can be found on the wiki page.
 
 ## Current State
-Abacus is being built for the Northwest Advanced Programming Workshop, a 3 week program in which students work in treams to complete a single project, following principles of agile development. Because of its short timeframe, Abacus is not even close to completed state. Below is a list of the current features and problems.
+Abacus is being built for the Northwest Advanced Programming Workshop, a 3 week program in which students work in teams to complete a single project, following principles of agile development. Because of its short timeframe, Abacus is not even close to completed state. Below is a list of the current features and problems.
 - [x] Basic number class
 - [x] Implementation of basic functions 
 - [x] Implementation of `exp`, `ln`, `sqrt` using the basic functions and Taylor Series

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

@@ -1,6 +1,7 @@
 package org.nwapw.abacus;
 
-import org.nwapw.abacus.config.ConfigurationObject;
+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;
@@ -11,9 +12,7 @@ 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 org.nwapw.abacus.window.Window;
 
-import javax.swing.*;
 import java.io.File;
 import java.io.IOException;
 import java.lang.reflect.InvocationTargetException;
@@ -47,24 +46,21 @@ public class Abacus {
     /**
      * The configuration loaded from a file.
      */
-    private ConfigurationObject configuration;
+    private Configuration configuration;
     /**
      * The tree builder used to construct a tree
      * from a string.
      */
     private TreeBuilder treeBuilder;
-    private Window window;
+
-    public boolean getStop(){
-        return window.getStop();
-    }
     /**
      * Creates a new instance of the Abacus calculator.
      */
     public Abacus() {
-        pluginManager = new PluginManager();
+        pluginManager = new PluginManager(this);
         numberReducer = new NumberReducer(this);
-        configuration = new ConfigurationObject(CONFIG_FILE);
+        configuration = new Configuration(CONFIG_FILE);
-        configuration.save(CONFIG_FILE);
+        configuration.saveTo(CONFIG_FILE);
         LexerTokenizer lexerTokenizer = new LexerTokenizer();
         ShuntingYardParser shuntingYardParser = new ShuntingYardParser(this);
         treeBuilder = new TreeBuilder<>(lexerTokenizer, shuntingYardParser);
@@ -82,13 +78,7 @@ public class Abacus {
     }
 
     public static void main(String[] args) {
-        try {
+        AbacusApplication.launch(AbacusApplication.class, args);
-            UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
-        } catch (ClassNotFoundException | InstantiationException | UnsupportedLookAndFeelException | IllegalAccessException e) {
-            e.printStackTrace();
-        }
-
-        new Window(new Abacus()).setVisible(true);
     }
 
     /**
@@ -124,7 +114,7 @@ public class Abacus {
      *
      * @return the configuration object.
      */
-    public ConfigurationObject getConfiguration() {
+    public Configuration getConfiguration() {
         return configuration;
     }
 
@@ -136,7 +126,7 @@ public class Abacus {
      * @return the resulting tree, null if the tree builder or the produced tree are null.
      */
     public TreeNode parseString(String input) {
-        return treeBuilder.fromString(input,this);
+        return treeBuilder.fromString(input);
     }
 
     /**
@@ -168,8 +158,4 @@ public class Abacus {
         }
         return null;
     }
-
-    public void setWindow(Window window) {
-        this.window = window;
-    }
 }

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

@@ -1,14 +1,108 @@
 package org.nwapw.abacus.config;
 
+import com.moandjiezana.toml.Toml;
+import com.moandjiezana.toml.TomlWriter;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.Set;
+
 /**
- * Serializable class that will be used to load TOML
+ * The configuration object that stores
- * configurations.
+ * options that the user can change.
  */
 public class Configuration {
 
     /**
-     * The type of number this calculator should use.
+     * The defaults TOML string.
      */
-    public String numberType;
+    private static final String DEFAULT_CONFIG =
+            "numberImplementation = \"naive\"\n" +
+            "disabledPlugins = []";
+    /**
+     * The defaults TOML object, parsed from the string.
+     */
+    private static final Toml DEFAULT_TOML = new Toml().read(DEFAULT_CONFIG);
+    /**
+     * The TOML writer used to write this configuration to a file.
+     */
+    private static final TomlWriter TOML_WRITER = new TomlWriter();
+
+    /**
+     * The implementation of the number that should be used.
+     */
+    private String numberImplementation = "<default>";
+    /**
+     * The list of disabled plugins in this Configuration.
+     */
+    private Set<String> disabledPlugins = new HashSet<>();
+
+    /**
+     * 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){
+        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){
+        this.numberImplementation = otherConfiguration.numberImplementation;
+        this.disabledPlugins.addAll(otherConfiguration.disabledPlugins);
+    }
+
+    /**
+     * 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){
+        if(file.getParentFile() != null) file.getParentFile().mkdirs();
+        try {
+            TOML_WRITER.write(this, file);
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+
+    /**
+     * Gets the number implementation from this configuration.
+     * @return the number implementation.
+     */
+    public String getNumberImplementation() {
+        return numberImplementation;
+    }
+
+    /**
+     * Sets the number implementation for the configuration
+     * @param numberImplementation the number implementation.
+     */
+    public void setNumberImplementation(String numberImplementation) {
+        this.numberImplementation = numberImplementation;
+    }
+
+    /**
+     * Gets the list of disabled plugins.
+     * @return the list of disabled plugins.
+     */
+    public Set<String> getDisabledPlugins() {
+        return disabledPlugins;
+    }
 
 }

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

@@ -1,111 +0,0 @@
-package org.nwapw.abacus.config;
-
-import com.moandjiezana.toml.Toml;
-import com.moandjiezana.toml.TomlWriter;
-
-import java.io.File;
-import java.io.IOException;
-
-/**
- * A configuration object, which essentially
- * manages saving, loading, and getting values
- * from the configuration. While Configuration is
- * the data model, this is the interface with it.
- */
-public class ConfigurationObject {
-
-    /**
-     * The writer used to store the configuration.
-     */
-    private static final TomlWriter TOML_WRITER = new TomlWriter();
-    /**
-     * The configuration instance being modeled.
-     */
-    private Configuration configuration;
-
-    /**
-     * Creates a new configuration object with the given config.
-     *
-     * @param config the config to use.
-     */
-    public ConfigurationObject(Configuration config) {
-        setup(config);
-    }
-
-    /**
-     * Create a configuration object by attempting to
-     * load a config from the given path, using the
-     * default configuration otherwise.
-     *
-     * @param path the path to attempt to load.
-     */
-    public ConfigurationObject(File path) {
-        Configuration config;
-        if (!path.exists()) {
-            config = getDefaultConfig();
-        } else {
-            Toml parse = new Toml();
-            parse.read(path);
-            config = parse.to(Configuration.class);
-        }
-        setup(config);
-    }
-
-    /**
-     * Creates a new configuration object with the
-     * default configuration.
-     */
-    public ConfigurationObject() {
-        setup(getDefaultConfig());
-    }
-
-    /**
-     * Sets up the ConfigurationObject.
-     * different constructors do different things,
-     * but they all lead here.
-     *
-     * @param configuration the configuration to set up with.
-     */
-    private void setup(Configuration configuration) {
-        this.configuration = configuration;
-    }
-
-    /**
-     * Creates a default configuration.
-     *
-     * @return the newly created default configuration.
-     */
-    private Configuration getDefaultConfig() {
-        configuration = new Configuration();
-        configuration.numberType = "naive";
-        return configuration;
-    }
-
-    /**
-     * Returns the implementation the user has requested to
-     * represent their numbers.
-     *
-     * @return the implementation name.
-     */
-    public String getNumberImplementation() {
-        return configuration.numberType;
-    }
-
-    /**
-     * Saves the ConfigurationObject to the given file.
-     *
-     * @param toFile the file to save ot.
-     * @return true if the save succeed, false if otherwise.
-     */
-    public boolean save(File toFile) {
-        if (toFile.getParentFile() != null) toFile.getParentFile().mkdirs();
-        try {
-            TOML_WRITER.write(configuration, toFile);
-            return true;
-        } catch (IOException e) {
-            e.printStackTrace();
-        }
-        return false;
-    }
-
-}

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

@@ -4,5 +4,5 @@ package org.nwapw.abacus.function;
  * The type of an operator, describing how it should behave.
  */
 public enum OperatorType {
-    BINARY_INFIX, UNARY_POSTFIX
+    BINARY_INFIX, UNARY_POSTFIX, UNARY_PREFIX
 }

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

@@ -0,0 +1,24 @@
+package org.nwapw.abacus.fx;
+
+import javafx.application.Application;
+import javafx.fxml.FXMLLoader;
+import javafx.scene.Parent;
+import javafx.scene.Scene;
+import javafx.stage.Stage;
+
+/**
+ * The main application class for JavaFX responsible for loading
+ * and displaying the fxml file.
+ */
+public class AbacusApplication extends Application {
+
+    @Override
+    public void start(Stage primaryStage) throws Exception {
+        Parent parent = FXMLLoader.load(getClass().getResource("/abacus.fxml"));
+        Scene mainScene = new Scene(parent, 320, 480);
+        primaryStage.setScene(mainScene);
+        primaryStage.setTitle("Abacus");
+        primaryStage.show();
+    }
+
+}

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

@@ -0,0 +1,240 @@
+package org.nwapw.abacus.fx;
+
+import javafx.collections.FXCollections;
+import javafx.collections.ObservableList;
+import javafx.fxml.FXML;
+import javafx.scene.control.*;
+import javafx.scene.control.cell.CheckBoxListCell;
+import javafx.scene.text.Text;
+import javafx.util.Callback;
+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.PluginListener;
+import org.nwapw.abacus.plugin.PluginManager;
+import org.nwapw.abacus.tree.TreeNode;
+
+import java.util.Set;
+
+
+/**
+ * The controller for the abacus FX UI, responsible
+ * for all the user interaction.
+ */
+public class AbacusController implements PluginListener {
+
+    /**
+     * The title for the apply alert dialog.
+     */
+    private static final String APPLY_MSG_TITLE = "\"Apply\" Needed";
+    /**
+     * The text for the header of the apply alert dialog.
+     */
+    private static final String APPLY_MSG_HEADER = "The settings have not been applied.";
+    /**
+     * 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.";
+    /**
+     * Constant string that is displayed if the text could not be lexed or parsed.
+     */
+    private static final String ERR_SYNTAX = "Syntax Error";
+    /**
+     * Constant string that is displayed if the tree could not be reduced.
+     */
+    private static final String ERR_EVAL = "Evaluation Error";
+
+    @FXML
+    private TabPane coreTabPane;
+    @FXML
+    private Tab calculateTab;
+    @FXML
+    private Tab settingsTab;
+    @FXML
+    private TableView<HistoryModel> historyTable;
+    @FXML
+    private TableColumn<HistoryModel, String> inputColumn;
+    @FXML
+    private TableColumn<HistoryModel, String> parsedColumn;
+    @FXML
+    private TableColumn<HistoryModel, String> outputColumn;
+    @FXML
+    private Text outputText;
+    @FXML
+    private TextField inputField;
+    @FXML
+    private Button inputButton;
+    @FXML
+    private ComboBox<String> numberImplementationBox;
+    @FXML
+    private ListView<ToggleablePlugin> enabledPluginView;
+
+    /**
+     * The list of history entries, created by the users.
+     */
+    private ObservableList<HistoryModel> historyData;
+
+    /**
+     * The abacus instance used for calculations and all
+     * other main processing code.
+     */
+    private ObservableList<String> numberImplementationOptions;
+
+    /**
+     * The list of plugin objects that can be toggled on and off,
+     * and, when reloaded, get added to the plugin manager's black list.
+     */
+    private ObservableList<ToggleablePlugin> enabledPlugins;
+
+    /**
+     * The abacus instance used for changing the plugin configuration.
+     */
+    private Abacus abacus;
+
+    /**
+     * Boolean which represents whether changes were made to the configuration.
+     */
+    private boolean changesMade;
+    /**
+     * Whether an alert about changes to the configuration was already shown.
+     */
+    private boolean reloadAlertShown;
+    /**
+     * The alert shown when a press to "apply" is needed.
+     */
+    private Alert reloadAlert;
+
+    /**
+     * Alerts the user if the changes they made
+     * have not yet been applied.
+     */
+    private void alertIfApplyNeeded(boolean ignorePrevious){
+        if(changesMade && (!reloadAlertShown || ignorePrevious)) {
+            reloadAlertShown = true;
+            reloadAlert.showAndWait();
+        }
+    }
+
+    @FXML
+    public void initialize(){
+        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>() {
+                    @Override
+                    public String toString(ToggleablePlugin object) {
+                        return object.getClassName().substring(object.getClassName().lastIndexOf('.') + 1);
+                    }
+
+                    @Override
+                    public ToggleablePlugin fromString(String string) {
+                        return new ToggleablePlugin(true, string);
+                    }
+                });
+
+        historyData = FXCollections.observableArrayList();
+        historyTable.setItems(historyData);
+        numberImplementationOptions = FXCollections.observableArrayList();
+        numberImplementationBox.setItems(numberImplementationOptions);
+        numberImplementationBox.getSelectionModel().selectedIndexProperty().addListener(e -> changesMade = true);
+        historyTable.getSelectionModel().setCellSelectionEnabled(true);
+        enabledPlugins = FXCollections.observableArrayList();
+        enabledPluginView.setItems(enabledPlugins);
+        enabledPluginView.setCellFactory(pluginCellFactory);
+        inputColumn.setCellFactory(cellFactory);
+        inputColumn.setCellValueFactory(cell -> cell.getValue().inputProperty());
+        parsedColumn.setCellFactory(cellFactory);
+        parsedColumn.setCellValueFactory(cell -> cell.getValue().parsedProperty());
+        outputColumn.setCellFactory(cellFactory);
+        outputColumn.setCellValueFactory(cell -> cell.getValue().outputProperty());
+        coreTabPane.getSelectionModel().selectedItemProperty().addListener((observable, oldValue, newValue) -> {
+            if(oldValue.equals(settingsTab)) alertIfApplyNeeded(true);
+        });
+
+        abacus = new Abacus();
+        abacus.getPluginManager().addListener(this);
+        abacus.getPluginManager().reload();
+
+        changesMade = false;
+        reloadAlertShown = false;
+
+        reloadAlert = new Alert(Alert.AlertType.WARNING);
+        reloadAlert.setTitle(APPLY_MSG_TITLE);
+        reloadAlert.setHeaderText(APPLY_MSG_HEADER);
+        reloadAlert.setContentText(APPLY_MSG_TEXT);
+    }
+
+    @FXML
+    private void performCalculation(){
+        inputButton.setDisable(true);
+        TreeNode constructedTree = abacus.parseString(inputField.getText());
+        if(constructedTree == null){
+            outputText.setText(ERR_SYNTAX);
+            inputButton.setDisable(false);
+            return;
+        }
+        NumberInterface evaluatedNumber = abacus.evaluateTree(constructedTree);
+        if(evaluatedNumber == null){
+            outputText.setText(ERR_EVAL);
+            inputButton.setDisable(false);
+            return;
+        }
+        outputText.setText(evaluatedNumber.toString());
+        historyData.add(new HistoryModel(inputField.getText(), constructedTree.toString(), evaluatedNumber.toString()));
+
+        inputButton.setDisable(false);
+        inputField.setText("");
+    }
+
+    @FXML
+    private void performSaveAndReload(){
+        performSave();
+        performReload();
+        changesMade = false;
+        reloadAlertShown = false;
+    }
+
+    @FXML
+    private void performReload(){
+        alertIfApplyNeeded(true);
+        abacus.getPluginManager().reload();
+    }
+
+    @FXML
+    private void performSave(){
+        Configuration configuration = abacus.getConfiguration();
+        configuration.setNumberImplementation(numberImplementationBox.getSelectionModel().getSelectedItem());
+        Set<String> disabledPlugins = configuration.getDisabledPlugins();
+        disabledPlugins.clear();
+        for(ToggleablePlugin pluginEntry : enabledPlugins){
+            if(!pluginEntry.isEnabled()) disabledPlugins.add(pluginEntry.getClassName());
+        }
+        configuration.saveTo(Abacus.CONFIG_FILE);
+        changesMade = false;
+        reloadAlertShown = false;
+    }
+
+    @Override
+    public void onLoad(PluginManager manager) {
+        Configuration configuration = abacus.getConfiguration();
+        Set<String> disabledPlugins = configuration.getDisabledPlugins();
+        numberImplementationOptions.addAll(abacus.getPluginManager().getAllNumbers());
+        String actualImplementation = configuration.getNumberImplementation();
+        String toSelect = (numberImplementationOptions.contains(actualImplementation)) ? actualImplementation : "<default>";
+        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);
+            enabledPlugins.add(plugin);
+        }
+    }
+
+    @Override
+    public void onUnload(PluginManager manager) {
+        enabledPlugins.clear();
+        numberImplementationOptions.clear();
+    }
+}

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

@@ -0,0 +1,35 @@
+package org.nwapw.abacus.fx;
+
+import javafx.scene.control.TableCell;
+import javafx.scene.input.MouseEvent;
+
+import java.awt.*;
+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.
+ */
+public class CopyableCell<S, T> extends TableCell<S, T> {
+
+    /**
+     * Creates a new copyable cell.
+     */
+    public CopyableCell(){
+        addEventFilter(MouseEvent.MOUSE_CLICKED, event -> {
+            if(event.getClickCount() == 2){
+                Toolkit.getDefaultToolkit().getSystemClipboard()
+                        .setContents(new StringSelection(getText()), null);
+            }
+        });
+    }
+
+    @Override
+    protected void updateItem(T item, boolean empty) {
+        super.updateItem(item, empty);
+        setText((empty || item == null) ? null : item.toString());
+        setGraphic(null);
+    }
+}

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

@@ -0,0 +1,87 @@
+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

@@ -0,0 +1,29 @@
+package org.nwapw.abacus.fx;
+
+import javafx.beans.property.BooleanProperty;
+import javafx.beans.property.SimpleBooleanProperty;
+
+public class ToggleablePlugin {
+
+    private final BooleanProperty enabled;
+    private final String className;
+
+    public ToggleablePlugin(boolean enabled, String className){
+        this.enabled = new SimpleBooleanProperty();
+        this.enabled.setValue(enabled);
+        this.className = className;
+    }
+
+    public BooleanProperty enabledProperty() {
+        return enabled;
+    }
+
+    public boolean isEnabled() {
+        return enabled.get();
+    }
+
+    public String getClassName() {
+        return className;
+    }
+
+}

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

@@ -93,6 +93,11 @@ public class NaiveNumber implements NumberInterface {
         return this.compareTo(ZERO);
     }
 
+    @Override
+    public int ceiling() {
+        return (int) Math.ceil(value);
+    }
+
     @Override
     public NumberInterface promoteTo(Class<? extends NumberInterface> toClass) {
         if (toClass == this.getClass()) return this;

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

@@ -79,6 +79,12 @@ public interface NumberInterface {
      */
     int signum();
 
+    /**
+     * 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();
+
     /**
      * Promotes this class to another number class.
      *

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

@@ -3,6 +3,10 @@ package org.nwapw.abacus.number;
 import java.math.BigDecimal;
 import java.math.RoundingMode;
 
+/**
+ * A number that uses a BigDecimal to store its value,
+ * leading to infinite possible precision.
+ */
 public class PreciseNumber implements NumberInterface {
 
     /**
@@ -44,12 +48,12 @@ public class PreciseNumber implements NumberInterface {
 
     @Override
     public int getMaxPrecision() {
-        return 54;
+        return 65;
     }
 
     @Override
     public NumberInterface multiply(NumberInterface multiplier) {
-        return new PreciseNumber(value.multiply(((PreciseNumber) multiplier).value));
+        return new PreciseNumber(this.value.multiply(((PreciseNumber) multiplier).value));
     }
 
     @Override
@@ -94,6 +98,11 @@ public class PreciseNumber implements NumberInterface {
         return value.signum();
     }
 
+    @Override
+    public int ceiling() {
+        return (int) Math.ceil(value.doubleValue());
+    }
+
     @Override
     public NumberInterface negate() {
         return new PreciseNumber(value.negate());
@@ -109,7 +118,7 @@ public class PreciseNumber implements NumberInterface {
 
     @Override
     public String toString() {
-        BigDecimal rounded = value.setScale(getMaxPrecision() - 4, RoundingMode.HALF_UP);
+        BigDecimal rounded = value.setScale(getMaxPrecision() - 15, RoundingMode.HALF_UP);
         return rounded.stripTrailingZeros().toPlainString();
     }
 }

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

@@ -1,6 +1,5 @@
 package org.nwapw.abacus.parsing;
 
-import org.nwapw.abacus.Abacus;
 import org.nwapw.abacus.tree.TreeNode;
 
 import java.util.List;
@@ -19,5 +18,5 @@ public interface Parser<T> {
      * @param tokens the tokens to construct a tree from.
      * @return the constructed tree, or null on error.
      */
-    public TreeNode constructTree(List<T> tokens,Abacus trace);
+    public TreeNode constructTree(List<T> tokens);
 }

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

@@ -34,8 +34,6 @@ public class ShuntingYardParser implements Parser<Match<TokenType>>, PluginListe
      */
     private Map<String, OperatorType> typeMap;
 
-    //private Abacus trace;
-
     /**
      * Creates a new Shunting Yard parser with the given Abacus instance.
      *
@@ -57,9 +55,12 @@ public class ShuntingYardParser implements Parser<Match<TokenType>>, PluginListe
     public List<Match<TokenType>> intoPostfix(List<Match<TokenType>> from) {
         ArrayList<Match<TokenType>> output = new ArrayList<>();
         Stack<Match<TokenType>> tokenStack = new Stack<>();
+        TokenType previousType;
+        TokenType matchType = null;
         while (!from.isEmpty()) {
             Match<TokenType> match = from.remove(0);
-            TokenType matchType = match.getType();
+            previousType = matchType;
+            matchType = match.getType();
             if (matchType == TokenType.NUM) {
                 output.add(match);
             } else if (matchType == TokenType.FUNCTION) {
@@ -76,13 +77,19 @@ public class ShuntingYardParser implements Parser<Match<TokenType>>, PluginListe
                     continue;
                 }
 
-                while (!tokenStack.empty()) {
+                if(tokenString.equals("-") && (previousType == null || previousType == TokenType.OP ||
+                        previousType == TokenType.OPEN_PARENTH)){
+                    from.add(0, new Match<>("`", TokenType.OP));
+                    continue;
+                }
+
+                while (!tokenStack.empty() && type == OperatorType.BINARY_INFIX) {
                     Match<TokenType> otherMatch = tokenStack.peek();
                     TokenType otherMatchType = otherMatch.getType();
                     if (!(otherMatchType == TokenType.OP || otherMatchType == TokenType.FUNCTION)) break;
 
                     if (otherMatchType == TokenType.OP) {
-                        int otherPrecedence = precedenceMap.get(match.getContent());
+                        int otherPrecedence = precedenceMap.get(otherMatch.getContent());
                         if (otherPrecedence < precedence ||
                                 (associativity == OperatorAssociativity.RIGHT && otherPrecedence == precedence)) {
                             break;
@@ -105,8 +112,8 @@ public class ShuntingYardParser implements Parser<Match<TokenType>>, PluginListe
         }
         while (!tokenStack.empty()) {
             Match<TokenType> match = tokenStack.peek();
-            TokenType matchType = match.getType();
+            TokenType newMatchType = match.getType();
-            if (!(matchType == TokenType.OP || matchType == TokenType.FUNCTION)) return null;
+            if (!(newMatchType == TokenType.OP || newMatchType == TokenType.FUNCTION)) return null;
             output.add(tokenStack.pop());
         }
         return output;
@@ -118,8 +125,7 @@ public class ShuntingYardParser implements Parser<Match<TokenType>>, PluginListe
      * @param matches the list of tokens from the source string.
      * @return the construct tree expression.
      */
-    public TreeNode constructRecursive(List<Match<TokenType>> matches,Abacus trace) {
+    public TreeNode constructRecursive(List<Match<TokenType>> matches) {
-        //this.trace = trace;
         if (matches.size() == 0) return null;
         Match<TokenType> match = matches.remove(0);
         TokenType matchType = match.getType();
@@ -127,22 +133,22 @@ public class ShuntingYardParser implements Parser<Match<TokenType>>, PluginListe
             String operator = match.getContent();
             OperatorType type = typeMap.get(operator);
             if (type == OperatorType.BINARY_INFIX) {
-                TreeNode right = constructRecursive(matches,trace);
+                TreeNode right = constructRecursive(matches);
-                TreeNode left = constructRecursive(matches,trace);
+                TreeNode left = constructRecursive(matches);
                 if (left == null || right == null) return null;
-                else return new BinaryInfixNode(operator, left, right,trace);
+                else return new BinaryNode(operator, left, right);
             } else {
-                TreeNode applyTo = constructRecursive(matches,trace);
+                TreeNode applyTo = constructRecursive(matches);
                 if (applyTo == null) return null;
-                else return new UnaryPrefixNode(operator, applyTo,trace);
+                else return new UnaryNode(operator, applyTo);
             }
         } else if (matchType == TokenType.NUM) {
             return new NumberNode(abacus.numberFromString(match.getContent()));
         } else if (matchType == TokenType.FUNCTION) {
             String functionName = match.getContent();
-            FunctionNode node = new FunctionNode(functionName,trace);
+            FunctionNode node = new FunctionNode(functionName);
             while (!matches.isEmpty() && matches.get(0).getType() != TokenType.INTERNAL_FUNCTION_END) {
-                TreeNode argument = constructRecursive(matches,trace);
+                TreeNode argument = constructRecursive(matches);
                 if (argument == null) return null;
                 node.prependChild(argument);
             }
@@ -154,10 +160,10 @@ public class ShuntingYardParser implements Parser<Match<TokenType>>, PluginListe
     }
 
     @Override
-    public TreeNode constructTree(List<Match<TokenType>> tokens,Abacus trace) {
+    public TreeNode constructTree(List<Match<TokenType>> tokens) {
         tokens = intoPostfix(new ArrayList<>(tokens));
         Collections.reverse(tokens);
-        return constructRecursive(tokens,trace);
+        return constructRecursive(tokens);
     }
 
     @Override

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

@@ -1,6 +1,5 @@
 package org.nwapw.abacus.parsing;
 
-import org.nwapw.abacus.Abacus;
 import org.nwapw.abacus.tree.TreeNode;
 
 import java.util.List;
@@ -42,10 +41,10 @@ public class TreeBuilder<T> {
      * @param input the string to parse into a tree.
      * @return the resulting tree.
      */
-    public TreeNode fromString(String input,Abacus trace) {
+    public TreeNode fromString(String input) {
         List<T> tokens = tokenizer.tokenizeString(input);
         if (tokens == null) return null;
-        return parser.constructTree(tokens,trace);
+        return parser.constructTree(tokens);
     }
 
 }

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

@@ -1,5 +1,6 @@
 package org.nwapw.abacus.plugin;
 
+import org.nwapw.abacus.Abacus;
 import org.nwapw.abacus.function.Function;
 import org.nwapw.abacus.function.Operator;
 import org.nwapw.abacus.number.NumberInterface;
@@ -52,11 +53,17 @@ public class PluginManager {
      * The list of plugin listeners attached to this instance.
      */
     private Set<PluginListener> listeners;
+    /**
+     * The abacus instance used to access other
+     * components of the application.
+     */
+    private Abacus abacus;
 
     /**
      * Creates a new plugin manager.
      */
-    public PluginManager() {
+    public PluginManager(Abacus abacus) {
+        this.abacus = abacus;
         loadedPluginClasses = new HashSet<>();
         plugins = new HashSet<>();
         cachedFunctions = new HashMap<>();
@@ -160,8 +167,13 @@ public class PluginManager {
      * Loads all the plugins in the PluginManager.
      */
     public void load() {
-        for (Plugin plugin : plugins) plugin.enable();
+        Set<String> disabledPlugins = abacus.getConfiguration().getDisabledPlugins();
         for (Plugin plugin : plugins) {
+            if(disabledPlugins.contains(plugin.getClass().getName())) continue;
+            plugin.enable();
+        }
+        for (Plugin plugin : plugins) {
+            if(disabledPlugins.contains(plugin.getClass().getName())) continue;
             allFunctions.addAll(plugin.providedFunctions());
             allOperators.addAll(plugin.providedOperators());
             allNumbers.addAll(plugin.providedNumbers());
@@ -173,11 +185,18 @@ public class PluginManager {
      * Unloads all the plugins in the PluginManager.
      */
     public void unload() {
-        for (Plugin plugin : plugins) plugin.disable();
+        listeners.forEach(e -> e.onUnload(this));
+        Set<String> disabledPlugins = abacus.getConfiguration().getDisabledPlugins();
+        for (Plugin plugin : plugins) {
+            if(disabledPlugins.contains(plugin.getClass().getName())) continue;
+            plugin.disable();
+        }
+        cachedFunctions.clear();
+        cachedOperators.clear();
+        cachedNumbers.clear();
         allFunctions.clear();
         allOperators.clear();
         allNumbers.clear();
-        listeners.forEach(e -> e.onUnload(this));
     }
 
     /**
@@ -185,7 +204,7 @@ public class PluginManager {
      */
     public void reload() {
         unload();
-        reload();
+        load();
     }
 
     /**
@@ -233,4 +252,12 @@ public class PluginManager {
         listeners.remove(listener);
     }
 
+    /**
+     * 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() {
+        return loadedPluginClasses;
+    }
 }

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

@@ -8,6 +8,8 @@ import org.nwapw.abacus.number.NaiveNumber;
 import org.nwapw.abacus.number.NumberInterface;
 import org.nwapw.abacus.number.PreciseNumber;
 
+import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.function.BiFunction;
 
 /**
@@ -16,6 +18,8 @@ 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, +
      */
@@ -48,6 +52,20 @@ public class StandardPlugin extends Plugin {
             return params[0].subtract(params[1]);
         }
     });
+    /**
+     * The negation operator, -
+     */
+    public static final Operator OP_NEGATE = new Operator(OperatorAssociativity.LEFT, OperatorType.UNARY_PREFIX, 0, new Function() {
+        @Override
+        protected boolean matchesParams(NumberInterface[] params) {
+            return params.length == 1;
+        }
+
+        @Override
+        protected NumberInterface applyInternal(NumberInterface[] params) {
+            return params[0].negate();
+        }
+    });
     /**
      * The multiplication operator, *
      */
@@ -72,16 +90,12 @@ 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 >= 1;
+            return params.length == 2;
         }
 
         @Override
         protected NumberInterface applyInternal(NumberInterface[] params) {
-            NumberInterface product = params[0];
+            return params[0].divide(params[1]);
-            for (int i = 1; i < params.length; i++) {
-                product = product.multiply(params[i]);
-            }
-            return product;
         }
     });
     /**
@@ -152,17 +166,40 @@ public class StandardPlugin extends Plugin {
 
         @Override
         protected NumberInterface applyInternal(NumberInterface[] params) {
-            boolean takeReciprocal = params[0].signum() == -1;
+            NumberInterface maxError = getMaxError(params[0]);
-            params[0] = FUNCTION_ABS.apply(params[0]);
+            int n = 0;
-            NumberInterface sum = sumSeries(params[0], StandardPlugin::getExpSeriesTerm, getNTermsExp(getMaxError(params[0]), params[0]));
+            if(params[0].signum() <= 0){
-            if (takeReciprocal) {
+                NumberInterface currentTerm = NaiveNumber.ONE.promoteTo(params[0].getClass()), sum = currentTerm;
-                sum = NaiveNumber.ONE.promoteTo(sum.getClass()).divide(sum);
+                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;
             }
-            return sum;
         }
     };
     /**
-     * The natural log function, ln(exp(1)) = 1
+     * The natural log function.
      */
     public static final Function FUNCTION_LN = new Function() {
         @Override
@@ -185,7 +222,7 @@ public class StandardPlugin extends Plugin {
                 } else {
                     param = param.multiply(new NaiveNumber(2).promoteTo(param.getClass()));
                     powersOf2--;
-                    if (param.subtract(NaiveNumber.ONE.promoteTo(param.getClass())).signum() != 1) {
+                    if (param.subtract(NaiveNumber.ONE.promoteTo(param.getClass())).signum() != -1) {
                         break;
                         //No infinite loop for you.
                     }
@@ -239,7 +276,7 @@ public class StandardPlugin extends Plugin {
         }
     };
     /**
-     * The square root function, sqrt(4) = 2
+     * The square root function.
      */
     public static final Function FUNCTION_SQRT = new Function() {
         @Override
@@ -257,39 +294,6 @@ public class StandardPlugin extends Plugin {
         super(manager);
     }
 
-    /**
-     * Returns the nth term of the Taylor series (centered at 0) of e^x
-     *
-     * @param n the term required (n >= 0).
-     * @param x the real number at which the series is evaluated.
-     * @return the nth term of the series.
-     */
-    private static NumberInterface getExpSeriesTerm(int n, NumberInterface x) {
-        return x.intPow(n).divide(OP_FACTORIAL.getFunction().apply((new NaiveNumber(n)).promoteTo(x.getClass())));
-    }
-
-    /**
-     * Returns the number of terms needed to evaluate the exponential function (at x)
-     * such that the error is at most maxError.
-     *
-     * @param maxError Maximum error permissible (This should probably be positive.)
-     * @param x        where the function is evaluated.
-     * @return the number of terms needed to evaluate the exponential function.
-     */
-    private static int getNTermsExp(NumberInterface maxError, NumberInterface x) {
-        //We need n such that |x^(n+1)| <= (n+1)! * maxError
-        //The variables LHS and RHS refer to the above inequality.
-        int n = 0;
-        x = FUNCTION_ABS.apply(x);
-        NumberInterface LHS = x, RHS = maxError;
-        while (LHS.compareTo(RHS) > 0) {
-            n++;
-            LHS = LHS.multiply(x);
-            RHS = RHS.multiply(new NaiveNumber(n + 1).promoteTo(RHS.getClass()));
-        }
-        return n;
-    }
-
     /**
      * Returns a partial sum of a series whose terms are given by the nthTermFunction, evaluated at x.
      *
@@ -323,6 +327,7 @@ public class StandardPlugin extends Plugin {
 
         registerOperator("+", OP_ADD);
         registerOperator("-", OP_SUBTRACT);
+        registerOperator("`", OP_NEGATE);
         registerOperator("*", OP_MULTIPLY);
         registerOperator("/", OP_DIVIDE);
         registerOperator("^", OP_CARET);
@@ -339,4 +344,19 @@ public class StandardPlugin extends Plugin {
 
     }
 
+    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

@@ -1,11 +1,9 @@
 package org.nwapw.abacus.tree;
 
-import org.nwapw.abacus.Abacus;
-
 /**
  * A tree node that represents an operation being applied to two operands.
  */
-public class BinaryInfixNode extends TreeNode {
+public class BinaryNode extends TreeNode {
 
     /**
      * The operation being applied.
@@ -19,9 +17,8 @@ public class BinaryInfixNode extends TreeNode {
      * The right node of the operation.
      */
     private TreeNode right;
-    private Abacus trace;
 
-    private BinaryInfixNode() {
+    private BinaryNode() {
     }
 
     /**
@@ -30,8 +27,8 @@ public class BinaryInfixNode extends TreeNode {
      *
      * @param operation the operation.
      */
-    public BinaryInfixNode(String operation,Abacus trace) {
+    public BinaryNode(String operation) {
-        this(operation, null, null,trace);
+        this(operation, null, null);
     }
 
     /**
@@ -42,11 +39,10 @@ public class BinaryInfixNode extends TreeNode {
      * @param left      the left node of the expression.
      * @param right     the right node of the expression.
      */
-    public BinaryInfixNode(String operation, TreeNode left, TreeNode right,Abacus trace) {
+    public BinaryNode(String operation, TreeNode left, TreeNode right) {
         this.operation = operation;
         this.left = left;
         this.right = right;
-        this.trace = trace;
     }
 
     /**
@@ -96,15 +92,10 @@ public class BinaryInfixNode extends TreeNode {
 
     @Override
     public <T> T reduce(Reducer<T> reducer) {
-        if(!trace.getStop()) {
+        T leftReduce = left.reduce(reducer);
-            T leftReduce = left.reduce(reducer);
+        T rightReduce = right.reduce(reducer);
-
+        if (leftReduce == null || rightReduce == null) return null;
-            T rightReduce = right.reduce(reducer);
+        return reducer.reduceNode(this, leftReduce, rightReduce);
-            if (leftReduce == null || rightReduce == null) return null;
-            return reducer.reduceNode(this, leftReduce, rightReduce);
-        }
-        return null;
-
     }
 
     @Override

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

@@ -1,7 +1,5 @@
 package org.nwapw.abacus.tree;
 
-import org.nwapw.abacus.Abacus;
-
 import java.util.ArrayList;
 import java.util.List;
 
@@ -18,7 +16,6 @@ public class FunctionNode extends TreeNode {
      * The list of arguments to the function.
      */
     private List<TreeNode> children;
-    private Abacus trace;
 
     /**
      * Creates a function node with no function.
@@ -31,10 +28,9 @@ public class FunctionNode extends TreeNode {
      *
      * @param function the function name.
      */
-    public FunctionNode(String function,Abacus trace) {
+    public FunctionNode(String function) {
         this.function = function;
         children = new ArrayList<>();
-        this.trace = trace;
     }
 
     /**

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

@@ -28,15 +28,15 @@ public class NumberReducer implements Reducer<NumberInterface> {
     public NumberInterface reduceNode(TreeNode node, Object... children) {
         if (node instanceof NumberNode) {
             return ((NumberNode) node).getNumber();
-        } else if (node instanceof BinaryInfixNode) {
+        } else if (node instanceof BinaryNode) {
             NumberInterface left = (NumberInterface) children[0];
             NumberInterface right = (NumberInterface) children[1];
-            Function function = abacus.getPluginManager().operatorFor(((BinaryInfixNode) node).getOperation()).getFunction();
+            Function function = abacus.getPluginManager().operatorFor(((BinaryNode) node).getOperation()).getFunction();
             if (function == null) return null;
             return function.apply(left, right);
-        } else if (node instanceof UnaryPrefixNode) {
+        } else if (node instanceof UnaryNode) {
             NumberInterface child = (NumberInterface) children[0];
-            Function functionn = abacus.getPluginManager().operatorFor(((UnaryPrefixNode) node).getOperation()).getFunction();
+            Function functionn = abacus.getPluginManager().operatorFor(((UnaryNode) node).getOperation()).getFunction();
             if (functionn == null) return null;
             return functionn.apply(child);
         } else if (node instanceof FunctionNode) {

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

@@ -1,8 +1,6 @@
 package org.nwapw.abacus.tree;
 
-import org.nwapw.abacus.Abacus;
+public class UnaryNode extends TreeNode {
-
-public class UnaryPrefixNode extends TreeNode {
 
     /**
      * The operation this node will apply.
@@ -12,15 +10,14 @@ public class UnaryPrefixNode extends TreeNode {
      * The tree node to apply the operation to.
      */
     private TreeNode applyTo;
-    private Abacus trace;
 
     /**
      * Creates a new node with the given operation and no child.
      *
      * @param operation the operation for this node.
      */
-    public UnaryPrefixNode(String operation,Abacus trace) {
+    public UnaryNode(String operation) {
-        this(operation, null,trace);
+        this(operation, null);
     }
 
     /**
@@ -29,20 +26,16 @@ public class UnaryPrefixNode extends TreeNode {
      * @param operation the operation for this node.
      * @param applyTo   the node to apply the function to.
      */
-    public UnaryPrefixNode(String operation, TreeNode applyTo,Abacus trace) {
+    public UnaryNode(String operation, TreeNode applyTo) {
         this.operation = operation;
         this.applyTo = applyTo;
-        this.trace = trace;
     }
 
     @Override
     public <T> T reduce(Reducer<T> reducer) {
-        if(!trace.getStop()) {
+        Object reducedChild = applyTo.reduce(reducer);
-            Object reducedChild = applyTo.reduce(reducer);
+        if (reducedChild == null) return null;
-            if (reducedChild == null) return null;
+        return reducer.reduceNode(this, reducedChild);
-            return reducer.reduceNode(this, reducedChild);
-        }
-        return null;
     }
 
     /**

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

@@ -15,14 +15,13 @@ import java.awt.event.MouseEvent;
  * The main UI window for the calculator.
  */
 public class Window extends JFrame {
-    
 
     private static final String CALC_STRING = "Calculate";
     private static final String SYNTAX_ERR_STRING = "Syntax Error";
     private static final String EVAL_ERR_STRING = "Evaluation Error";
     private static final String NUMBER_SYSTEM_LABEL = "Number Type:";
     private static final String FUNCTION_LABEL = "Functions:";
-    private static final String STOP_STRING = "Stop";
+
     /**
      * Array of Strings to which the "calculate" button's text
      * changes. For instance, in the graph tab, the name will
@@ -91,10 +90,7 @@ public class Window extends JFrame {
      * The "submit" button.
      */
     private JButton inputEnterButton;
-    /**
+
-     * The stop calculations button.
-     */
-    private JButton inputStopButton;
     /**
      * The side panel for separate configuration.
      */
@@ -117,80 +113,26 @@ public class Window extends JFrame {
      * The list of functions available to the user.
      */
     private JComboBox<String> functionList;
-    /**
-     * Thread used for calculations
-     */
-    private Thread calculateThread;
-    /**
-     * Check if currently calculating.
-     */
-    private boolean calculating;
-    /**
-     * Checks if thread should stop calculating.
-     */
-    private boolean stopCalculating;
-    /**
-     * Test variable to check number of threads running in the calculator.
-     */
-    private int count;
-    /**
-     * ActionListener that stops calculations.
-     */
-    private ActionListener stopListener = (event) -> {
-        //System.out.println(count++);  //Shows about how many calculation threads are running with the calculating=false command
-        //calculating = false;          //Ignores result of calculation and allows for the start of a new calculation
-        stopCalculating = true;         //Stops calculation at the next node check
-        //calculateThread.stop();         //Stops thread no matter what, Unsafe
-    };
 
     /**
-     * Node check to get whether nodes should continue calculating.
+     * Action listener that causes the input to be evaluated.
-     * @return boolean stop calculations if true.
-     */
-    public boolean getStop(){
-        return stopCalculating;
-    }
-
-    /**
-     * ActionListener that runs all calculations.
      */
     private ActionListener evaluateListener = (event) -> {
-        Runnable calculate = new Runnable() {
+        TreeNode parsedExpression = abacus.parseString(inputField.getText());
-            public void run() {
+        if (parsedExpression == null) {
-                boolean skip = false;
+            lastOutputArea.setText(SYNTAX_ERR_STRING);
-                calculating = true;
+            return;
-                TreeNode parsedExpression = null;
-                parsedExpression = abacus.parseString(inputField.getText());
-                if (parsedExpression == null) {
-                    lastOutputArea.setText(SYNTAX_ERR_STRING);
-                    skip = true;
-                }
-                if(!skip){
-                    NumberInterface numberInterface = abacus.evaluateTree(parsedExpression);
-                    if (numberInterface == null) {
-                        lastOutputArea.setText(EVAL_ERR_STRING);
-                        calculating = false;
-                        stopCalculating = false;
-
-                        return;
-                    }
-                    if(calculateThread.equals(Thread.currentThread())) {
-                        lastOutput = numberInterface.toString();
-                        historyModel.addEntry(new HistoryTableModel.HistoryEntry(inputField.getText(), parsedExpression, lastOutput));
-                        historyTable.invalidate();
-                        lastOutputArea.setText(lastOutput);
-                        inputField.setText("");
-                        calculating = false;
-                        stopCalculating = false;
-                    }
-                }
-            }
-        };
-        if(!calculating) {
-            calculateThread = new Thread(calculate);
-            calculateThread.setName("a-"+System.currentTimeMillis());
-            calculateThread.start();
         }
+        NumberInterface numberInterface = abacus.evaluateTree(parsedExpression);
+        if (numberInterface == null) {
+            lastOutputArea.setText(EVAL_ERR_STRING);
+            return;
+        }
+        lastOutput = numberInterface.toString();
+        historyModel.addEntry(new HistoryTableModel.HistoryEntry(inputField.getText(), parsedExpression, lastOutput));
+        historyTable.invalidate();
+        lastOutputArea.setText(lastOutput);
+        inputField.setText("");
     };
 
     /**
@@ -201,14 +143,6 @@ public class Window extends JFrame {
             evaluateListener,
             null
     };
-    /**
-     * Array of listeners that tell the stop button how to behave
-     * at a given input tab.
-     */
-    private ActionListener[] stopListeners = {
-            stopListener,
-            null
-    };
 
     /**
      * Creates a new window with the given manager.
@@ -218,7 +152,6 @@ public class Window extends JFrame {
     public Window(Abacus abacus) {
         this();
         this.abacus = abacus;
-        abacus.setWindow(this);
     }
 
     /**
@@ -227,36 +160,25 @@ public class Window extends JFrame {
     private Window() {
         super();
 
-        //variables related to when calculations occur
-        stopCalculating = false;
-        calculating = true;
-
         lastOutput = "";
 
-        //default window properties
         setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
         setSize(320, 480);
 
-        //initiates input objects
         inputField = new JTextField();
         inputEnterButton = new JButton(CALC_STRING);
-        inputStopButton = new JButton(STOP_STRING);
 
-        //adds input objects into Panel
         inputPanel = new JPanel();
         inputPanel.setLayout(new BorderLayout());
-        inputPanel.add(inputStopButton, BorderLayout.SOUTH);
+        inputPanel.add(inputField, BorderLayout.CENTER);
-        inputPanel.add(inputField, BorderLayout.NORTH);
+        inputPanel.add(inputEnterButton, BorderLayout.SOUTH);
-        inputPanel.add(inputEnterButton, BorderLayout.CENTER);
 
-        //initiates output objects in calculator tab
         historyModel = new HistoryTableModel();
         historyTable = new JTable(historyModel);
         historyScroll = new JScrollPane(historyTable);
         lastOutputArea = new JTextArea(lastOutput);
         lastOutputArea.setEditable(false);
 
-        //adds output objects into Panel
         calculationPanel = new JPanel();
         calculationPanel.setLayout(new BorderLayout());
         calculationPanel.add(historyScroll, BorderLayout.CENTER);
@@ -286,8 +208,6 @@ public class Window extends JFrame {
         settingsPanel.add(numberSystemPanel);
         settingsPanel.add(functionSelectPanel);
 
-        calculating = false;
-
         pane = new JTabbedPane();
         pane.add("Calculator", calculationPanel);
         pane.add("Settings", settingsPanel);
@@ -295,23 +215,17 @@ public class Window extends JFrame {
             int selectionIndex = pane.getSelectedIndex();
             boolean enabled = INPUT_ENABLED[selectionIndex];
             ActionListener listener = listeners[selectionIndex];
-            ActionListener stopUsed = stopListeners[selectionIndex];
             inputEnterButton.setText(BUTTON_NAMES[selectionIndex]);
             inputField.setEnabled(enabled);
             inputEnterButton.setEnabled(enabled);
-            inputStopButton.setEnabled(enabled);
 
             for (ActionListener removingListener : inputEnterButton.getActionListeners()) {
                 inputEnterButton.removeActionListener(removingListener);
                 inputField.removeActionListener(removingListener);
             }
-            for(ActionListener removingListener : inputStopButton.getActionListeners()){
-                inputStopButton.removeActionListener(removingListener);
-            }
             if (listener != null) {
                 inputEnterButton.addActionListener(listener);
                 inputField.addActionListener(listener);
-                inputStopButton.addActionListener(stopUsed);
             }
         });
         add(pane, BorderLayout.CENTER);
@@ -319,7 +233,6 @@ public class Window extends JFrame {
 
         inputEnterButton.addActionListener(evaluateListener);
         inputField.addActionListener(evaluateListener);
-        inputStopButton.addActionListener(stopListener);
         historyTable.addMouseListener(new MouseAdapter() {
             @Override
             public void mouseClicked(MouseEvent e) {

src/main/resources/abacus.fxml

@@ -0,0 +1,63 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<?import javafx.geometry.Insets?>
+<?import javafx.scene.control.*?>
+<?import javafx.scene.layout.BorderPane?>
+<?import javafx.scene.layout.VBox?>
+<?import javafx.scene.text.Text?>
+<?import javafx.scene.layout.HBox?>
+<?import javafx.scene.layout.GridPane?>
+<?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">
+            <Tab fx:id="calculateTab" text="Calculator" closable="false">
+                <BorderPane>
+                    <center>
+                        <TableView fx:id="historyTable">
+                            <columnResizePolicy>
+                                <TableView fx:constant="CONSTRAINED_RESIZE_POLICY"/>
+                            </columnResizePolicy>
+                            <columns>
+                                <TableColumn fx:id="inputColumn" text="Input" sortable="false"/>
+                                <TableColumn fx:id="parsedColumn" text="Parsed" sortable="false"/>
+                                <TableColumn fx:id="outputColumn" text="Output" sortable="false"/>
+                            </columns>
+                        </TableView>
+                    </center>
+                    <bottom>
+                        <VBox>
+                            <ScrollPane prefHeight="50" vbarPolicy="NEVER">
+                                <padding>
+                                    <Insets top="10" bottom="10" left="10" right="10"/>
+                                </padding>
+                                <Text fx:id="outputText"/>
+                            </ScrollPane>
+                            <TextField fx:id="inputField" onAction="#performCalculation"/>
+                            <Button fx:id="inputButton" text="Calculate" maxWidth="Infinity"
+                                    onAction="#performCalculation"/>
+                        </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>
+                    <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">
+                        <Button text="Apply" onAction="#performSave"/>
+                        <Button text="Reload Plugins" onAction="#performReload"/>
+                        <Button text="Apply and Reload" onAction="#performSaveAndReload"/>
+                    </FlowPane>
+                </GridPane>
+            </Tab>
+        </TabPane>
+    </center>
+
+</BorderPane>