Merge branch 'plugins'

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

@@ -1,8 +1,10 @@
 package org.nwapw.abacus.plugin;
 
 import org.nwapw.abacus.function.Function;
+import org.nwapw.abacus.function.Operator;
 
 import java.util.HashMap;
+import java.util.Set;
 
 /**
  * A plugin class that can be externally implemented and loaded via the
@@ -17,11 +19,19 @@ public abstract class Plugin {
      * A hash map of functions mapped to their string names.
      */
     private HashMap<String, Function> functions;
+    /**
+     * A hash map of operators mapped to their string names.
+     */
+    private HashMap<String, Operator> operators;
     /**
      * The plugin manager in which to search for functions
      * not inside this package,
      */
     private PluginManager manager;
+    /**
+     * Whether this plugin has been loaded.
+     */
+    private boolean enabled;
 
     private Plugin(){ }
 
@@ -32,15 +42,24 @@ public abstract class Plugin {
     public Plugin(PluginManager manager) {
         this.manager = manager;
         functions = new HashMap<>();
+        operators = new HashMap<>();
+        enabled = false;
     }
 
     /**
-     * Determines whether the current plugin provides the given function name.
-     * @param functionName the name of the function provided.
-     * @return true of the function exists, false if it doesn't.
+     * Gets the list of functions provided by this plugin.
+     * @return the list of registered functions.
      */
-    public final boolean hasFunction(String functionName) {
-        return functions.containsKey(functionName);
+    public final Set<String> providedFunctions(){
+        return functions.keySet();
+    }
+
+    /**
+     * Gets the list of functions provided by this plugin.
+     * @return the list of registered functions.
+     */
+    public final Set<String> providedOperators(){
+        return operators.keySet();
     }
 
     /**
@@ -52,37 +71,91 @@ public abstract class Plugin {
         return functions.get(functionName);
     }
 
+    /**
+     * Gets an operator under the given operator name.
+     * @param operatorName the name of the operator to get.
+     * @return the operator, or null if this plugin doesn't provide it.
+     */
+    public final Operator getOperator(String operatorName) {
+        return operators.get(operatorName);
+    }
+
+    /**
+     * Enables the function, loading the necessary instances
+     * of functions.
+     */
+    public final void enable(){
+        if(enabled) return;
+        onEnable();
+        enabled = true;
+    }
+
+    /**
+     * Disables the plugin, clearing loaded data store by default
+     * and calling its disable() method.
+     */
+    public final void disable(){
+        if(!enabled) return;
+        onDisable();
+        functions.clear();
+        operators.clear();
+        enabled = false;
+    }
+
     /**
      * To be used in load(). Registers a function abstract class with the
      * plugin internally, which makes it accessible to the plugin manager.
      * @param name the name to register by.
      * @param toRegister the function implementation.
-     * @return true if the function was registered successfully, false if not.
      */
-    protected final boolean registerFunction(String name, Function toRegister) {
-        if(functionFor(name) == null){
-            functions.put(name, toRegister);
-            return true;
-        }
-        return false;
+    protected final void registerFunction(String name, Function toRegister) {
+        functions.put(name, toRegister);
+    }
+
+    /**
+     * To be used in load(). Registers an operator abstract class
+     * with the plugin internally, which makes it accessible to
+     * the plugin manager.
+     * @param name the name of the operator.
+     * @param operator the operator to register.
+     */
+    protected final void registerOperator(String name, Operator operator) {
+        operators.put(name, operator);
     }
 
     /**
      * Searches the PluginManager for the given function name.
      * This can be used by the plugins internally in order to call functions
      * they do not provide.
-     * @param name then name for which to search
+     * @param name the name for which to search
      * @return the resulting function, or null if none was found for that name.
      */
     protected final Function functionFor(String name) {
         return manager.functionFor(name);
     }
 
+    /**
+     * Searches the PluginManager for the given operator name.
+     * This can be used by the plugins internally in order to call
+     * operations they do not provide.
+     * @param name the name for which to search
+     * @return the resulting operator, or null if none was found for that name.
+     */
+    protected final Operator operatorFor(String name) {
+        return manager.operatorFor(name);
+    }
+
     /**
      * Abstract method to be overridden by plugin implementation, in which the plugins
      * are supposed to register the functions they provide and do any other
      * necessary setup.
      */
-    public abstract void load();
+    public abstract void onEnable();
+
+    /**
+     * Abstract method overridden by the plugin implementation, in which the plugins
+     * are supposed to dispose of loaded functions, operators, and macros.
+     */
+    public abstract void onDisable();
 
 }

src/org/nwapw/abacus/plugin/PluginListener.java

@@ -0,0 +1,20 @@
+package org.nwapw.abacus.plugin;
+
+/**
+ * A listener that responds to changes in the PluginManager.
+ */
+public interface PluginListener {
+
+    /**
+     * Called when the PluginManager loads plugins.
+     * @param manager the manager that fired the event.
+     */
+    public void onLoad(PluginManager manager);
+
+    /**
+     * Called when the PluginManager unloads all its plugins.
+     * @param manager the manager that fired the event.
+     */
+    public void onUnload(PluginManager manager);
+
+}

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

@@ -1,10 +1,10 @@
 package org.nwapw.abacus.plugin;
 
 import org.nwapw.abacus.function.Function;
+import org.nwapw.abacus.function.Operator;
 
 import java.lang.reflect.InvocationTargetException;
-import java.util.ArrayList;
-import java.util.HashMap;
+import java.util.*;
 
 /**
  * A class that controls instances of plugins, allowing for them
@@ -21,6 +21,23 @@ public class PluginManager {
      * that is, found in a plugin and returned.
      */
     private HashMap<String, Function> cachedFunctions;
+    /**
+     * List of operators tha have been cached,
+     * that is, found in a plugin and returned.
+     */
+    private HashMap<String, Operator> cachedOperators;
+    /**
+     * List of all functions loaded by the plugins.
+     */
+    private HashSet<String> allFunctions;
+    /**
+     * List of all operators loaded by the plugins.
+     */
+    private HashSet<String> allOperators;
+    /**
+     * The list of plugin listeners attached to this instance.
+     */
+    private HashSet<PluginListener> listeners;
 
     /**
      * Creates a new plugin manager.
@@ -28,27 +45,58 @@ public class PluginManager {
     public PluginManager(){
         plugins = new ArrayList<>();
         cachedFunctions = new HashMap<>();
+        cachedOperators = new HashMap<>();
+        allFunctions = new HashSet<>();
+        allOperators = new HashSet<>();
+        listeners = new HashSet<>();
     }
 
+    /**
+     * Searches the plugin list for a certain value, retrieving the Plugin's
+     * list of items of the type using the setFunction and getting the value
+     * of it is available via getFunction. If the value is contained
+     * in the cache, it returns the cached value instead.
+     * @param plugins the plugin list to search.
+     * @param cache the cache to use
+     * @param setFunction the function to retrieve a set of available T's from the plugin
+     * @param getFunction the function to get the T value under the given name
+     * @param name the name to search for
+     * @param <T> the type of element being search
+     * @return the retrieved element, or null if it was not found.
+     */
+    private static <T> T searchCached(Collection<Plugin> plugins, Map<String, T> cache,
+                                      java.util.function.Function<Plugin, Set<String>> setFunction,
+                                      java.util.function.BiFunction<Plugin, String, T> getFunction,
+                                      String name){
+        if(cache.containsKey(name)) return cache.get(name);
+
+        T loadedValue = null;
+        for(Plugin plugin : plugins){
+            if(setFunction.apply(plugin).contains(name)){
+                loadedValue = getFunction.apply(plugin, name);
+                break;
+            }
+        }
+
+        cache.put(name, loadedValue);
+        return loadedValue;
+    }
     /**
      * Gets a function under the given name.
      * @param name the name of the function
      * @return the function under the given name.
      */
     public Function functionFor(String name){
-        if(cachedFunctions.containsKey(name)) {
-            return cachedFunctions.get(name);
-        }
+        return searchCached(plugins, cachedFunctions, Plugin::providedFunctions, Plugin::getFunction, name);
+    }
 
-        Function loadedFunction = null;
-        for(Plugin plugin : plugins){
-            if(plugin.hasFunction(name)){
-                loadedFunction = plugin.getFunction(name);
-                break;
-            }
-        }
-        cachedFunctions.put(name, loadedFunction);
-        return loadedFunction;
+    /**
+     * Gets an operator under the given name.
+     * @param name the name of the operator.
+     * @return the operator under the given name.
+     */
+    public Operator operatorFor(String name){
+        return searchCached(plugins, cachedOperators, Plugin::providedOperators, Plugin::getOperator, name);
     }
 
     /**
@@ -56,8 +104,6 @@ public class PluginManager {
      * @param plugin the plugin to add.
      */
     public void addInstantiated(Plugin plugin){
-        plugin.load();
-        cachedFunctions.clear();
         plugins.add(plugin);
     }
 
@@ -75,4 +121,66 @@ public class PluginManager {
         }
     }
 
+    /**
+     * Loads all the plugins in the PluginManager.
+     */
+    public void load(){
+        for(Plugin plugin : plugins) plugin.enable();
+        for(Plugin plugin : plugins){
+            allFunctions.addAll(plugin.providedFunctions());
+            allOperators.addAll(plugin.providedOperators());
+        }
+        listeners.forEach(e -> e.onLoad(this));
+    }
+
+    /**
+     * Unloads all the plugins in the PluginManager.
+     */
+    public void unload(){
+        for(Plugin plugin : plugins) plugin.disable();
+        allFunctions.clear();
+        allOperators.clear();
+        listeners.forEach(e -> e.onUnload(this));
+    }
+
+    /**
+     * Reloads all the plugins in the PluginManager.
+     */
+    public void reload(){
+        unload();
+        reload();
+    }
+
+    /**
+     * Gets all the functions loaded by the Plugin Manager.
+     * @return the set of all functions that were loaded.
+     */
+    public HashSet<String> getAllFunctions() {
+        return allFunctions;
+    }
+
+    /**
+     * Gets all the operators loaded by the Plugin Manager.
+     * @return the set of all operators that were loaded.
+     */
+    public HashSet<String> getAllOperators() {
+        return allOperators;
+    }
+
+    /**
+     * Adds a plugin change listener to this plugin manager.
+     * @param listener the listener to add.
+     */
+    public void addListener(PluginListener listener){
+        listeners.add(listener);
+    }
+
+    /**
+     * Remove the plugin change listener from this plugin manager.
+     * @param listener the listener to remove.
+     */
+    public void removeListener(PluginListener listener){
+        listeners.remove(listener);
+    }
+    
 }

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

@@ -20,7 +20,7 @@ public class StandardPlugin extends Plugin {
     }
 
     @Override
-    public void load() {
+    public void onEnable() {
         registerFunction("+", new Function() {
             @Override
             protected boolean matchesParams(NumberInterface[] params) {
@@ -234,11 +234,16 @@ public class StandardPlugin extends Plugin {
         });
     }
 
+    @Override
+    public void onDisable() {
+
+    }
+
     /**
      * 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
+     * @return the nth term of the series.
      */
     private NumberInterface getExpSeriesTerm(int n, NumberInterface x){
         return x.intPow(n).divide(this.getFunction("!").apply((new NaiveNumber(n)).promoteTo(x.getClass())));
@@ -249,7 +254,7 @@ public class StandardPlugin extends Plugin {
      * 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
+     * @return the number of terms needed to evaluated the exponential function.
      */
     private int getNTermsExp(NumberInterface maxError, NumberInterface x) {
         //We need n such that |x^(n+1)| <= (n+1)! * maxError
@@ -284,7 +289,7 @@ public class StandardPlugin extends Plugin {
     /**
      * 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
+     * @return the maximum error.
      */
     private NumberInterface getMaxError(NumberInterface number){
         return (new NaiveNumber(10)).promoteTo(number.getClass()).intPow(-number.precision());