src/jdk.scripting.nashorn.shell/share/classes/jdk/nashorn/tools/jjs/HistoryObject.java

@@ -23,21 +23,27 @@
  * questions.
  */
 
 package jdk.nashorn.tools.jjs;
 
+import java.io.BufferedReader;
+import java.io.File;
+import java.io.FileReader;
 import java.io.IOException;
+import java.io.PrintWriter;
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.Set;
+import java.util.function.Consumer;
 import java.util.function.Function;
 import java.util.function.Supplier;
 import jdk.internal.jline.console.history.FileHistory;
 import jdk.internal.jline.console.history.History;
 import jdk.nashorn.api.scripting.AbstractJSObject;
 import jdk.nashorn.api.scripting.JSObject;
 import jdk.nashorn.internal.runtime.JSType;
+import static jdk.nashorn.internal.runtime.ECMAErrors.typeError;
 import static jdk.nashorn.internal.runtime.ScriptRuntime.UNDEFINED;
 
 /*
  * A script friendly object that exposes history of commands to scripts.
  */

@@ -45,31 +51,70 @@
     private static final Set<String> props;
     static {
         final HashSet<String> s = new HashSet<>();
         s.add("clear");
         s.add("forEach");
+        s.add("load");
         s.add("print");
+        s.add("save");
         s.add("size");
         s.add("toString");
         props = Collections.unmodifiableSet(s);
     }
 
     private final FileHistory hist;
+    private final PrintWriter err;
+    private final Consumer<String> evaluator;
 
-    HistoryObject(final FileHistory hist) {
+    HistoryObject(final FileHistory hist, final PrintWriter err,
+            final Consumer<String> evaluator) {
         this.hist = hist;
+        this.err = err;
+        this.evaluator = evaluator;
+    }
+
+    @Override
+    public boolean isFunction() {
+        return true;
+    }
+
+    @Override
+    public Object call(final Object thiz, final Object... args) {
+        if (args.length > 0) {
+            int index = JSType.toInteger(args[0]);
+            if (index < 0) {
+                index += (hist.size() - 1);
+            } else {
+                index--;
+            }
+
+            if (index >= 0 && index < (hist.size() - 1)) {
+                final CharSequence src = hist.get(index);
+                hist.replace(src);
+                err.println(src);
+                evaluator.accept(src.toString());
+            } else {
+                hist.removeLast();
+                err.println("no history entry @ " + (index + 1));
+            }
+        }
+        return UNDEFINED;
     }
 
     @Override
     public Object getMember(final String name) {
         switch (name) {
             case "clear":
                 return (Runnable)hist::clear;
             case "forEach":
                 return (Function<JSObject, Object>)this::iterate;
+            case "load":
+                return (Consumer<Object>)this::load;
             case "print":
                 return (Runnable)this::print;
+            case "save":
+                return (Consumer<Object>)this::save;
             case "size":
                 return hist.size();
             case "toString":
                 return (Supplier<String>)this::toString;
         }

@@ -96,13 +141,36 @@
     @Override
     public Set<String> keySet() {
         return props;
     }
 
+    private void save(final Object obj) {
+        final File file = getFile(obj);
+        try (final PrintWriter pw = new PrintWriter(file)) {
+            for (History.Entry e : hist) {
+                pw.println(e.value());
+            }
+        } catch (final IOException exp) {
+            throw new RuntimeException(exp);
+        }
+    }
+
+    private void load(final Object obj) {
+        final File file = getFile(obj);
+        String item = null;
+        try (final BufferedReader r = new BufferedReader(new FileReader(file))) {
+            while ((item = r.readLine()) != null) {
+                hist.add(item);
+            }
+        } catch (final IOException exp) {
+            throw new RuntimeException(exp);
+        }
+    }
+
     private void print() {
         for (History.Entry e : hist) {
-            System.out.println(e.value());
+            System.out.printf("%3d %s\n", e.index() + 1, e.value());
         }
     }
 
     private Object iterate(final JSObject func) {
         for (History.Entry e : hist) {

@@ -110,6 +178,19 @@
                 break; // return true from callback to skip iteration
             }
         }
         return UNDEFINED;
     }
+
+    private static File getFile(final Object obj) {
+        File file = null;
+        if (obj instanceof String) {
+            file = new File((String)obj);
+        } else if (obj instanceof File) {
+            file = (File)obj;
+        } else {
+            throw typeError("not.a.file", JSType.toString(obj));
+        }
+
+        return file;
+    }
 }