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

*** 23,43 ****
--- 23,49 ----
   * 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.
   */
*** 45,75 ****
      private static final Set<String> props;
      static {
          final HashSet<String> s = new HashSet<>();
          s.add("clear");
          s.add("forEach");
          s.add("print");
          s.add("size");
          s.add("toString");
          props = Collections.unmodifiableSet(s);
      }
  
      private final FileHistory hist;
  
!     HistoryObject(final FileHistory hist) {
          this.hist = hist;
      }
  
      @Override
      public Object getMember(final String name) {
          switch (name) {
              case "clear":
                  return (Runnable)hist::clear;
              case "forEach":
                  return (Function<JSObject, Object>)this::iterate;
              case "print":
                  return (Runnable)this::print;
              case "size":
                  return hist.size();
              case "toString":
                  return (Supplier<String>)this::toString;
          }
--- 51,120 ----
      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, 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;
          }
*** 96,108 ****
      @Override
      public Set<String> keySet() {
          return props;
      }
  
      private void print() {
          for (History.Entry e : hist) {
!             System.out.println(e.value());
          }
      }
  
      private Object iterate(final JSObject func) {
          for (History.Entry e : hist) {
--- 141,176 ----
      @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.printf("%3d %s\n", e.index() + 1, e.value());
          }
      }
  
      private Object iterate(final JSObject func) {
          for (History.Entry e : hist) {
*** 110,115 ****
--- 178,196 ----
                  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;
+     }
  }