Fix some documentation glitches.

build.gradle

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

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

@@ -0,0 +1,7 @@
+package org.nwapw.abacus.function;
+
+public enum DocumentationType {
+
+    FUNCTION
+
+}

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

@@ -7,6 +7,7 @@ import javafx.collections.FXCollections;
 import javafx.collections.ObservableList;
 import javafx.collections.transformation.FilteredList;
 import javafx.fxml.FXML;
+import javafx.scene.Node;
 import javafx.scene.control.*;
 import javafx.scene.control.cell.CheckBoxListCell;
 import javafx.scene.text.Text;
@@ -14,6 +15,8 @@ import javafx.util.Callback;
 import javafx.util.StringConverter;
 import org.nwapw.abacus.Abacus;
 import org.nwapw.abacus.config.Configuration;
+import org.nwapw.abacus.function.Documentation;
+import org.nwapw.abacus.function.DocumentationType;
 import org.nwapw.abacus.number.ComputationInterruptedException;
 import org.nwapw.abacus.number.NumberInterface;
 import org.nwapw.abacus.plugin.ClassFinder;
@@ -24,7 +27,10 @@ import org.nwapw.abacus.tree.TreeNode;
 
 import java.io.File;
 import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Comparator;
 import java.util.Set;
+import java.util.stream.Collectors;
 
 
 /**
@@ -97,7 +103,7 @@ public class AbacusController implements PluginListener {
     @FXML
     private TextField computationLimitField;
     @FXML
-    private ListView<String> functionListView;
+    private ListView<Documentation> functionListView;
     @FXML
     private TextField functionListSearchField;
 
@@ -120,11 +126,11 @@ public class AbacusController implements PluginListener {
     /**
      * The list of functions that are registered in the calculator.
      */
-    private ObservableList<String> functionList;
+    private ObservableList<Documentation> functionList;
     /**
      * The filtered list displayed to the user.
      */
-    private FilteredList<String> functionFilter;
+    private FilteredList<Documentation> functionFilter;
 
     /**
      * The abacus instance used for changing the plugin configuration.
@@ -216,7 +222,7 @@ public class AbacusController implements PluginListener {
         Callback<TableColumn<HistoryModel, String>, TableCell<HistoryModel, String>> cellFactory =
                 param -> new CopyableCell<>();
         Callback<ListView<ToggleablePlugin>, ListCell<ToggleablePlugin>> pluginCellFactory =
-                param -> new CheckBoxListCell<>(ToggleablePlugin::getEnabledProperty, new StringConverter<ToggleablePlugin>() {
+                param -> new CheckBoxListCell<>(ToggleablePlugin::enabledProperty, new StringConverter<ToggleablePlugin>() {
                     @Override
                     public String toString(ToggleablePlugin object) {
                         return object.getClassName().substring(object.getClassName().lastIndexOf('.') + 1);
@@ -224,15 +230,15 @@ public class AbacusController implements PluginListener {
 
                     @Override
                     public ToggleablePlugin fromString(String string) {
-                        return new ToggleablePlugin(string, true);
+                        return new ToggleablePlugin(true, string);
                     }
                 });
-
         functionList = FXCollections.observableArrayList();
         functionFilter = new FilteredList<>(functionList, (s) -> true);
         functionListView.setItems(functionFilter);
         functionListSearchField.textProperty().addListener((observable, oldValue, newValue) ->
-                functionFilter.setPredicate((newValue.length() == 0) ? ((s) -> true) : ((s) -> s.contains(newValue))));
+                functionFilter.setPredicate((newValue.length() == 0) ? ((s) -> true) : ((s) -> s.matches(newValue))));
+        functionListView.setCellFactory(param -> new DocumentationCell());
         historyData = FXCollections.observableArrayList();
         historyTable.setItems(historyData);
         numberImplementationOptions = FXCollections.observableArrayList();
@@ -243,11 +249,11 @@ public class AbacusController implements PluginListener {
         enabledPluginView.setItems(enabledPlugins);
         enabledPluginView.setCellFactory(pluginCellFactory);
         inputColumn.setCellFactory(cellFactory);
-        inputColumn.setCellValueFactory(cell -> cell.getValue().getInputProperty());
+        inputColumn.setCellValueFactory(cell -> cell.getValue().inputProperty());
         parsedColumn.setCellFactory(cellFactory);
-        parsedColumn.setCellValueFactory(cell -> cell.getValue().getParsedProperty());
+        parsedColumn.setCellValueFactory(cell -> cell.getValue().parsedProperty());
         outputColumn.setCellFactory(cellFactory);
-        outputColumn.setCellValueFactory(cell -> cell.getValue().getOutputProperty());
+        outputColumn.setCellValueFactory(cell -> cell.getValue().outputProperty());
         coreTabPane.getSelectionModel().selectedItemProperty().addListener((observable, oldValue, newValue) -> {
             if (oldValue.equals(settingsTab)) alertIfApplyNeeded(true);
         });
@@ -343,12 +349,14 @@ public class AbacusController implements PluginListener {
         numberImplementationBox.getSelectionModel().select(toSelect);
         for (Class<?> pluginClass : abacus.getPluginManager().getLoadedPluginClasses()) {
             String fullName = pluginClass.getName();
-            ToggleablePlugin plugin = new ToggleablePlugin(fullName, !disabledPlugins.contains(fullName));
-            plugin.getEnabledProperty().addListener(e -> changesMade = true);
+            ToggleablePlugin plugin = new ToggleablePlugin(!disabledPlugins.contains(fullName), fullName);
+            plugin.enabledProperty().addListener(e -> changesMade = true);
             enabledPlugins.add(plugin);
         }
-        functionList.addAll(manager.getAllFunctions());
-        functionList.sort(String::compareTo);
+        PluginManager pluginManager = abacus.getPluginManager();
+        functionList.addAll(manager.getAllFunctions().stream().map(name -> pluginManager.documentationFor(name, DocumentationType.FUNCTION))
+                .collect(Collectors.toCollection(ArrayList::new)));
+        functionList.sort(Comparator.comparing(Documentation::getCodeName));
     }
 
     @Override

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

@@ -0,0 +1,58 @@
+package org.nwapw.abacus.fx;
+
+import javafx.scene.control.Label;
+import javafx.scene.control.ListCell;
+import javafx.scene.control.TitledPane;
+import javafx.scene.layout.VBox;
+import org.nwapw.abacus.function.Documentation;
+
+public class DocumentationCell extends ListCell<Documentation> {
+
+    private Label codeNameLabel;
+    private Label nameLabel;
+    private Label description;
+    private Label longDescription;
+    private TitledPane titledPane;
+
+    public DocumentationCell(){
+        VBox vbox = new VBox();
+        vbox.setSpacing(10);
+        titledPane = new TitledPane();
+        codeNameLabel = new Label();
+        nameLabel = new Label();
+        description = new Label();
+        longDescription = new Label();
+        codeNameLabel.setWrapText(true);
+        nameLabel.setWrapText(true);
+        description.setWrapText(true);
+        longDescription.setWrapText(true);
+        vbox.getChildren().add(codeNameLabel);
+        vbox.getChildren().add(nameLabel);
+        vbox.getChildren().add(description);
+        vbox.getChildren().add(longDescription);
+        titledPane.textProperty().bindBidirectional(codeNameLabel.textProperty());
+        titledPane.setContent(vbox);
+        titledPane.setExpanded(false);
+        titledPane.prefWidthProperty().bind(widthProperty());
+
+        visibleProperty().addListener((a, b, c) -> titledPane.setExpanded(false));
+    }
+
+    @Override
+    protected void updateItem(Documentation item, boolean empty) {
+        super.updateItem(item, empty);
+        if(empty){
+            codeNameLabel.setText("");
+            nameLabel.setText("");
+            description.setText("");
+            longDescription.setText("");
+            setGraphic(null);
+        } else {
+            codeNameLabel.setText(item.getCodeName());
+            nameLabel.setText(item.getName());
+            description.setText(item.getDescription());
+            longDescription.setText(item.getLongDescription());
+            setGraphic(titledPane);
+        }
+    }
+}

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

@@ -0,0 +1,97 @@
+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 +1,60 @@
+package org.nwapw.abacus.fx;
+
+import javafx.beans.property.BooleanProperty;
+import javafx.beans.property.SimpleBooleanProperty;
+
+/**
+ * Class that represents an entry in the plugin check box list.
+ * The changes from this property are written to the config on application.
+ */
+public class ToggleablePlugin {
+
+    /**
+     * The property that determines whether the plugin will be enabled.
+     */
+    private final BooleanProperty enabled;
+    /**
+     * The name of the class this entry toggles.
+     */
+    private final String className;
+
+    /**
+     * Creates a new toggleable plugin with the given properties.
+     *
+     * @param enabled   the enabled / disabled state at the beginning.
+     * @param className the name of the class this plugin toggles.
+     */
+    public ToggleablePlugin(boolean enabled, String className) {
+        this.enabled = new SimpleBooleanProperty();
+        this.enabled.setValue(enabled);
+        this.className = className;
+    }
+
+    /**
+     * Gets the enabled property of this plugin.
+     *
+     * @return the enabled property.
+     */
+    public BooleanProperty enabledProperty() {
+        return enabled;
+    }
+
+    /**
+     * Checks if this plugin entry should be enabled.
+     *
+     * @return whether this plugin will be enabled.
+     */
+    public boolean isEnabled() {
+        return enabled.get();
+    }
+
+    /**
+     * Gets the class name this plugin toggles.
+     *
+     * @return the class name that should be disabled.
+     */
+    public String getClassName() {
+        return className;
+    }
+
+}

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

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

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

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

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

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

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

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

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

@@ -1,5 +1,7 @@
 package org.nwapw.abacus.plugin;
 
+import org.nwapw.abacus.function.Documentation;
+import org.nwapw.abacus.function.DocumentationType;
 import org.nwapw.abacus.function.Function;
 import org.nwapw.abacus.function.Operator;
 import org.nwapw.abacus.number.NumberInterface;
@@ -94,6 +96,15 @@ public abstract class Plugin {
         manager.registerNumberImplementation(name, implementation);
     }
 
+    /**
+     * To be used in load(). Registers a documentation instance
+     * used to explain some element of the plugin to the user.
+     * @param documentation the documentation instance.
+     */
+    protected final void registerDocumentation(Documentation documentation){
+        manager.registerDocumentation(documentation);
+    }
+
     /**
      * Searches the PluginManager for the given function name.
      * This can be used by the plugins internally in order to call functions
@@ -130,6 +141,17 @@ public abstract class Plugin {
         return manager.numberImplementationFor(name);
     }
 
+    /**
+     * Searches the PluginManager for the given documentation name and type.
+     *
+     * @param name the name for which to search.
+     * @param type the type of documentation to search for.
+     * @return the found documentation, or null if none was found.
+     */
+    protected final Documentation documentationFor(String name, DocumentationType type){
+        return manager.documentationFor(name, type);
+    }
+
     /**
      * 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

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

@@ -1,6 +1,8 @@
 package org.nwapw.abacus.plugin;
 
 import org.nwapw.abacus.Abacus;
+import org.nwapw.abacus.function.Documentation;
+import org.nwapw.abacus.function.DocumentationType;
 import org.nwapw.abacus.function.Function;
 import org.nwapw.abacus.function.Operator;
 import org.nwapw.abacus.number.NumberInterface;
@@ -34,6 +36,10 @@ public class PluginManager {
      * The map of number implementations registered by the plugins.
      */
     private Map<String, NumberImplementation> registeredNumberImplementations;
+    /**
+     * The map of documentation for functions registered by the plugins.
+     */
+    private Set<Documentation> registeredDocumentation;
     /**
      * The list of number implementations that have been
      * found by their implementation class.
@@ -65,6 +71,7 @@ public class PluginManager {
         registeredFunctions = new HashMap<>();
         registeredOperators = new HashMap<>();
         registeredNumberImplementations = new HashMap<>();
+        registeredDocumentation = new HashSet<>();
         cachedInterfaceImplementations = new HashMap<>();
         cachedPi = new HashMap<>();
         listeners = new HashSet<>();
@@ -97,6 +104,15 @@ public class PluginManager {
         registeredNumberImplementations.put(name, implementation);
     }
 
+    /**
+     * Registers the given documentation with the plugin manager,
+     * making it accessible to the plugin manager etc.
+     * @param documentation the documentation to register.
+     */
+    public void registerDocumentation(Documentation documentation){
+        registeredDocumentation.add(documentation);
+    }
+
     /**
      * Gets the function registered under the given name.
      * @param name the name of the function.
@@ -124,6 +140,27 @@ public class PluginManager {
         return registeredNumberImplementations.get(name);
     }
 
+    /**
+     * Gets the documentation for the given entity of the given type.
+     * @param name the name of the entity to search for.
+     * @param type the type that this entity is, to filter out similarly named documentation.
+     * @return the documentation object.
+     */
+    public Documentation documentationFor(String name, DocumentationType type){
+        Documentation toReturn = null;
+        for(Documentation entry : registeredDocumentation){
+            if(entry.getCodeName().equals(name) && entry.getType() == type) {
+                toReturn = entry;
+                break;
+            }
+        }
+        if(toReturn == null){
+            toReturn = new Documentation(name, "", "", "", type);
+            registerDocumentation(toReturn);
+        }
+        return toReturn;
+    }
+
     /**
      * Gets the number implementation for the given implementation class.
      *
@@ -212,6 +249,7 @@ public class PluginManager {
         registeredFunctions.clear();
         registeredOperators.clear();
         registeredNumberImplementations.clear();
+        registeredDocumentation.clear();
         cachedInterfaceImplementations.clear();
         cachedPi.clear();
         listeners.forEach(e -> e.onUnload(this));

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

@@ -1,15 +1,18 @@
 package org.nwapw.abacus.plugin;
 
-import org.nwapw.abacus.function.Function;
-import org.nwapw.abacus.function.Operator;
-import org.nwapw.abacus.function.OperatorAssociativity;
-import org.nwapw.abacus.function.OperatorType;
+import org.nwapw.abacus.function.*;
+import org.nwapw.abacus.lexing.pattern.Match;
 import org.nwapw.abacus.number.NaiveNumber;
 import org.nwapw.abacus.number.NumberInterface;
 import org.nwapw.abacus.number.PreciseNumber;
+import org.nwapw.abacus.parsing.Parser;
+import org.nwapw.abacus.parsing.ShuntingYardParser;
+import org.nwapw.abacus.tree.TokenType;
+import org.nwapw.abacus.tree.TreeNode;
 
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.List;
 import java.util.function.BiFunction;
 
 /**
@@ -188,7 +191,7 @@ public class StandardPlugin extends Plugin {
          */
         private NumberInterface getLogPartialSum(NumberInterface x) {
 
-            NumberInterface maxError = x.getMaxError();
+            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;
@@ -207,7 +210,7 @@ public class StandardPlugin extends Plugin {
          * @return the value of log(2) with the appropriate precision.
          */
         private NumberInterface getLog2(NumberInterface number) {
-            NumberInterface maxError = number.getMaxError();
+            NumberInterface maxError = getMaxError(number);
             //NumberInterface errorBound = fromInt(number.getClass(), 1);
             //We'll use the series \sigma_{n >= 1) ((1/3^n + 1/4^n) * 1/n)
             //In the following, a=1/3^n, b=1/4^n, c = 1/n.
@@ -301,11 +304,16 @@ public class StandardPlugin extends Plugin {
 
         @Override
         protected NumberInterface applyInternal(NumberInterface[] params) {
-            NumberInterface maxError = params[0].getMaxError();
+            NumberInterface maxError = getMaxError(params[0]);
             int n = 0;
-            if (params[0].signum() < 0) {
-                NumberInterface[] negatedParams = {params[0].negate()};
-               return fromInt(params[0].getClass(), 1).divide(applyInternal(negatedParams));
+            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.
@@ -347,7 +355,7 @@ public class StandardPlugin extends Plugin {
                 return NaiveNumber.ONE.promoteTo(params[1].getClass());
             //Detect integer bases:
             if(params[0].fractionalPart().compareTo(fromInt(params[0].getClass(), 0)) == 0
-                    && FUNCTION_ABS.apply(params[1]).compareTo(fromInt(params[0].getClass(), Integer.MAX_VALUE)) < 0
+                    && FUNCTION_ABS.apply(params[0]).compareTo(fromInt(params[0].getClass(), Integer.MAX_VALUE)) < 0
                     && FUNCTION_ABS.apply(params[1]).compareTo(fromInt(params[1].getClass(), 1)) >= 0){
                 NumberInterface[] newParams = {params[0], params[1].fractionalPart()};
                 return params[0].intPow(params[1].floor().intValue()).multiply(applyInternal(newParams));
@@ -471,6 +479,16 @@ public class StandardPlugin extends Plugin {
         return sum;
     }
 
+    /**
+     * Returns the maximum error based on the precision of the class of number.
+     *
+     * @param number Any instance of the NumberInterface in question (should return an appropriate precision).
+     * @return the maximum error.
+     */
+    private static NumberInterface getMaxError(NumberInterface number) {
+        return fromInt(number.getClass(), 10).intPow(-number.getMaxPrecision());
+    }
+
     /**
      * A factorial function that uses memoization for each number class; it efficiently
      * computes factorials of non-negative integers.
@@ -502,7 +520,7 @@ public class StandardPlugin extends Plugin {
      */
     private static NumberInterface sinTaylor(NumberInterface x) {
         NumberInterface power = x, multiplier = x.multiply(x).negate(), currentTerm = x, sum = x;
-        NumberInterface maxError = x.getMaxError();
+        NumberInterface maxError = getMaxError(x);
         int n = 1;
         do {
             n += 2;
@@ -568,6 +586,35 @@ public class StandardPlugin extends Plugin {
         registerFunction("sec", functionSec);
         registerFunction("csc", functionCsc);
         registerFunction("cot", functionCot);
+
+        registerDocumentation(new Documentation("abs", "Absolute Value", "Finds the distance " +
+                "from zero of a number.", "Given a number, this function finds the distance form " +
+                "zero of a number, effectively turning negative numbers into positive ones.\n\n" +
+                "Example: abs(-2) -> 2", DocumentationType.FUNCTION));
+        registerDocumentation(new Documentation("exp", "Exponentiate", "Brings e to the given power.",
+                "This function evaluates e to the power of the given value, and is the inverse " +
+                        "of the natural logarithm.\n\n" +
+                        "Example: exp(1) -> 2.718...", DocumentationType.FUNCTION));
+        registerDocumentation(new Documentation("ln", "Natural Logarithm", "Gets the natural " +
+                "logarithm of the given value.", "The natural logarithm of a number is " +
+                "the power that e has to be brought to to be equal to the number.\n\n" +
+                "Example: ln(2.718) -> 1", DocumentationType.FUNCTION));
+        registerDocumentation(new Documentation("sqrt", "Square Root", "Finds the square root " +
+                "of the number.", "A square root a of a number is defined such that a times a is equal " +
+                "to that number.\n\n" +
+                "Example: sqrt(4) -> 2", DocumentationType.FUNCTION));
+        registerDocumentation(new Documentation("sin", "Sine", "Computes the sine of the given angle, " +
+                "in radians.", "", DocumentationType.FUNCTION));
+        registerDocumentation(new Documentation("cos", "Cosine", "Computes the cosine of the given angle, " +
+                "in radians.", "", DocumentationType.FUNCTION));
+        registerDocumentation(new Documentation("tan", "Tangent", "Computes the tangent of the given angle, " +
+                "in radians.", "", DocumentationType.FUNCTION));
+        registerDocumentation(new Documentation("sec", "Secant", "Computes the secant of the given angle, " +
+                "in radians.", "", DocumentationType.FUNCTION));
+        registerDocumentation(new Documentation("csc", "Cosecant", "Computes the cosecant of the given angle, " +
+                "in radians.", "", DocumentationType.FUNCTION));
+        registerDocumentation(new Documentation("cot", "Cotangent", "Computes the cotangent of the given angle, " +
+                "in radians.", "", DocumentationType.FUNCTION));
     }
 
     @Override

src/main/kotlin/org/nwapw/abacus/function/Documentation.kt

@@ -0,0 +1,26 @@
+package org.nwapw.abacus.function
+
+/**
+ * A data class used for storing information about a function.
+ *
+ * The Documentation class holds the information necessary to display the information
+ * about a function to the user.
+ *
+ * @param codeName the name of the function as it occurs in code.
+ * @param name the name of the function in English.
+ * @param description the short description of this function.
+ * @param longDescription the full description of this function.
+ * @param type the things this documentation maps to.
+ */
+data class Documentation(val codeName: String, val name: String,
+                         val description: String, val longDescription: String,
+                         val type: DocumentationType) {
+
+    fun matches(other: String): Boolean {
+        return codeName.toLowerCase().contains(other.toLowerCase()) ||
+                name.toLowerCase().contains(other.toLowerCase()) ||
+                description.toLowerCase().contains(other.toLowerCase()) ||
+                longDescription.toLowerCase().contains(other.toLowerCase())
+    }
+
+}

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

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

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

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

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

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