--- a/src/jdk.scripting.nashorn.shell/share/classes/jdk/nashorn/tools/jjs/Main.java	Mon Aug 17 13:17:25 2015 +0530
+++ b/src/jdk.scripting.nashorn.shell/share/classes/jdk/nashorn/tools/jjs/Main.java	Mon Aug 17 18:36:28 2015 +0530
@@ -31,33 +31,16 @@
 import java.io.IOException;
 import java.io.OutputStream;
 import java.io.PrintWriter;
-import java.util.Iterator;
-import java.util.List;
 import java.util.prefs.Preferences;
-import jdk.nashorn.api.tree.AssignmentTree;
-import jdk.nashorn.api.tree.BinaryTree;
-import jdk.nashorn.api.tree.CompilationUnitTree;
-import jdk.nashorn.api.tree.CompoundAssignmentTree;
-import jdk.nashorn.api.tree.ConditionalExpressionTree;
-import jdk.nashorn.api.tree.ExpressionTree;
-import jdk.nashorn.api.tree.ExpressionStatementTree;
-import jdk.nashorn.api.tree.InstanceOfTree;
-import jdk.nashorn.api.tree.MemberSelectTree;
-import jdk.nashorn.api.tree.SimpleTreeVisitorES5_1;
-import jdk.nashorn.api.tree.Tree;
-import jdk.nashorn.api.tree.UnaryTree;
-import jdk.nashorn.api.tree.Parser;
+import jdk.internal.jline.console.completer.Completer;
+import jdk.internal.jline.console.UserInterruptException;
 import jdk.nashorn.api.scripting.NashornException;
 import jdk.nashorn.internal.objects.Global;
 import jdk.nashorn.internal.runtime.Context;
-import jdk.nashorn.internal.runtime.ErrorManager;
 import jdk.nashorn.internal.runtime.JSType;
 import jdk.nashorn.internal.runtime.ScriptEnvironment;
-import jdk.nashorn.internal.runtime.ScriptObject;
 import jdk.nashorn.internal.runtime.ScriptRuntime;
 import jdk.nashorn.tools.Shell;
-import jdk.internal.jline.console.completer.Completer;
-import jdk.internal.jline.console.UserInterruptException;
 
 /**
  * Interactive command line Shell for Nashorn.
@@ -114,70 +97,7 @@
         final PrintWriter err = context.getErr();
         final Global oldGlobal = Context.getGlobal();
         final boolean globalChanged = (oldGlobal != global);
-        final Parser parser = Parser.create();
-
-        // simple source "tab completer" for nashorn
-        final Completer completer = new Completer() {
-            @Override
-            public int complete(final String test, final int cursor, final List<CharSequence> result) {
-                // check that cursor is at the end of test string. Do not complete in the middle!
-                if (cursor != test.length()) {
-                    return cursor;
-                }
-
-                // if it has a ".", then assume it is a member selection expression
-                final int idx = test.lastIndexOf('.');
-                if (idx == -1) {
-                    return cursor;
-                }
-
-                // stuff before the last "."
-                final String exprBeforeDot = test.substring(0, idx);
-
-                // Make sure that completed code will have a member expression! Adding ".x" as a
-                // random property/field name selected to make it possible to be a proper member select
-                final ExpressionTree topExpr = getTopLevelExpression(parser, exprBeforeDot + ".x");
-                if (topExpr == null) {
-                    // did not parse to be a top level expression, no suggestions!
-                    return cursor;
-                }
-
-
-                // Find 'right most' member select expression's start position
-                final int startPosition = (int) getStartOfMemberSelect(topExpr);
-                if (startPosition == -1) {
-                    // not a member expression that we can handle for completion
-                    return cursor;
-                }
-
-                // The part of the right most member select expression before the "."
-                final String objExpr = test.substring(startPosition, idx);
-
-                // try to evaluate the object expression part as a script
-                Object obj = null;
-                try {
-                    obj = context.eval(global, objExpr, global, "<suggestions>");
-                } catch (Exception ignored) {
-                    // throw the exception - this is during tab-completion
-                }
-
-                if (obj != null && obj != ScriptRuntime.UNDEFINED) {
-                    // where is the last dot? Is there a partial property name specified?
-                    final String prefix = test.substring(idx + 1);
-                    if (prefix.isEmpty()) {
-                        // no user specified "prefix". List all properties of the object
-                        result.addAll(PropertiesHelper.getProperties(obj));
-                        return cursor;
-                    } else {
-                        // list of properties matching the user specified prefix
-                        result.addAll(PropertiesHelper.getProperties(obj, prefix));
-                        return idx + 1;
-                    }
-                }
-
-                return cursor;
-            }
-        };
+        final Completer completer = new NashornCompleter(context, global);
 
         try (final Console in = new Console(System.in, System.out, PREFS, completer)) {
             if (globalChanged) {
@@ -229,66 +149,4 @@
 
         return SUCCESS;
     }
-
-    // returns ExpressionTree if the given code parses to a top level expression.
-    // Or else returns null.
-    private ExpressionTree getTopLevelExpression(final Parser parser, final String code) {
-        try {
-            final CompilationUnitTree cut = parser.parse("<code>", code, null);
-            final List<? extends Tree> stats = cut.getSourceElements();
-            if (stats.size() == 1) {
-                final Tree stat = stats.get(0);
-                if (stat instanceof ExpressionStatementTree) {
-                    return ((ExpressionStatementTree)stat).getExpression();
-                }
-            }
-        } catch (final NashornException ignored) {
-            // ignore any parser error. This is for completion anyway!
-            // And user will get that error later when the expression is evaluated.
-        }
-
-        return null;
-    }
-
-
-    private long getStartOfMemberSelect(final ExpressionTree expr) {
-        if (expr instanceof MemberSelectTree) {
-            return ((MemberSelectTree)expr).getStartPosition();
-        }
-
-        final Tree rightMostExpr = expr.accept(new SimpleTreeVisitorES5_1<Tree, Void>() {
-            @Override
-            public Tree visitAssignment(final AssignmentTree at, final Void v) {
-                return at.getExpression();
-            }
-
-            @Override
-            public Tree visitCompoundAssignment(final CompoundAssignmentTree cat, final Void v) {
-                return cat.getExpression();
-            }
-
-            @Override
-            public Tree visitConditionalExpression(final ConditionalExpressionTree cet, final Void v) {
-                return cet.getFalseExpression();
-            }
-
-            @Override
-            public Tree visitBinary(final BinaryTree bt, final Void v) {
-                return bt.getRightOperand();
-            }
-
-            @Override
-            public Tree visitInstanceOf(final InstanceOfTree it, final Void v) {
-                return it.getType();
-            }
-
-            @Override
-            public Tree visitUnary(final UnaryTree ut, final Void v) {
-                return ut.getExpression();
-            }
-        }, null);
-
-        return (rightMostExpr instanceof MemberSelectTree)?
-            rightMostExpr.getStartPosition() : -1L;
-    }
 }

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jdk.scripting.nashorn.shell/share/classes/jdk/nashorn/tools/jjs/NashornCompleter.java	Mon Aug 17 18:36:28 2015 +0530
@@ -0,0 +1,207 @@
+/*
+ * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package jdk.nashorn.tools.jjs;
+
+import java.util.List;
+import jdk.internal.jline.console.completer.Completer;
+import jdk.nashorn.api.tree.AssignmentTree;
+import jdk.nashorn.api.tree.BinaryTree;
+import jdk.nashorn.api.tree.CompilationUnitTree;
+import jdk.nashorn.api.tree.CompoundAssignmentTree;
+import jdk.nashorn.api.tree.ConditionalExpressionTree;
+import jdk.nashorn.api.tree.ExpressionTree;
+import jdk.nashorn.api.tree.ExpressionStatementTree;
+import jdk.nashorn.api.tree.InstanceOfTree;
+import jdk.nashorn.api.tree.MemberSelectTree;
+import jdk.nashorn.api.tree.SimpleTreeVisitorES5_1;
+import jdk.nashorn.api.tree.Tree;
+import jdk.nashorn.api.tree.UnaryTree;
+import jdk.nashorn.api.tree.Parser;
+import jdk.nashorn.api.scripting.NashornException;
+import jdk.nashorn.internal.objects.Global;
+import jdk.nashorn.internal.runtime.Context;
+import jdk.nashorn.internal.runtime.ScriptRuntime;
+
+// A simple source completer for nashorn
+final class NashornCompleter implements Completer {
+    private final Context context;
+    private final Global global;
+    private final Parser parser;
+
+    NashornCompleter(final Context context, final Global global) {
+        this.context = context;
+        this.global = global;
+        this.parser = Parser.create();
+    }
+
+    @Override
+    public int complete(final String test, final int cursor, final List<CharSequence> result) {
+        // check that cursor is at the end of test string. Do not complete in the middle!
+        if (cursor != test.length()) {
+            return cursor;
+        }
+
+        // if it has a ".", then assume it is a member selection expression
+        final int idx = test.lastIndexOf('.');
+        if (idx == -1) {
+            if (isIdentifier(test)) {
+                // identifier - return matching global variable names, if any
+                result.addAll(PropertiesHelper.getProperties(global, test));
+                return idx + 1;
+            }
+
+            return cursor;
+        }
+
+        // stuff before the last "."
+        final String exprBeforeDot = test.substring(0, idx);
+
+        // Make sure that completed code will have a member expression! Adding ".x" as a
+        // random property/field name selected to make it possible to be a proper member select
+        final ExpressionTree topExpr = getTopLevelExpression(parser, exprBeforeDot + ".x");
+        if (topExpr == null) {
+            // did not parse to be a top level expression, no suggestions!
+            return cursor;
+        }
+
+
+        // Find 'right most' member select expression's start position
+        final int startPosition = (int) getStartOfMemberSelect(topExpr);
+        if (startPosition == -1) {
+            // not a member expression that we can handle for completion
+            return cursor;
+        }
+
+        // The part of the right most member select expression before the "."
+        final String objExpr = test.substring(startPosition, idx);
+
+        // try to evaluate the object expression part as a script
+        Object obj = null;
+        try {
+            obj = context.eval(global, objExpr, global, "<suggestions>");
+        } catch (Exception ignored) {
+            // throw the exception - this is during tab-completion
+        }
+
+        if (obj != null && obj != ScriptRuntime.UNDEFINED) {
+            // where is the last dot? Is there a partial property name specified?
+            final String prefix = test.substring(idx + 1);
+            if (prefix.isEmpty()) {
+                // no user specified "prefix". List all properties of the object
+                result.addAll(PropertiesHelper.getProperties(obj));
+                return cursor;
+            } else {
+                // list of properties matching the user specified prefix
+                result.addAll(PropertiesHelper.getProperties(obj, prefix));
+                return idx + 1;
+            }
+        }
+
+        return cursor;
+    }
+
+    // returns ExpressionTree if the given code parses to a top level expression.
+    // Or else returns null.
+    private ExpressionTree getTopLevelExpression(final Parser parser, final String code) {
+        try {
+            final CompilationUnitTree cut = parser.parse("<code>", code, null);
+            final List<? extends Tree> stats = cut.getSourceElements();
+            if (stats.size() == 1) {
+                final Tree stat = stats.get(0);
+                if (stat instanceof ExpressionStatementTree) {
+                    return ((ExpressionStatementTree)stat).getExpression();
+                }
+            }
+        } catch (final NashornException ignored) {
+            // ignore any parser error. This is for completion anyway!
+            // And user will get that error later when the expression is evaluated.
+        }
+
+        return null;
+    }
+
+
+    private long getStartOfMemberSelect(final ExpressionTree expr) {
+        if (expr instanceof MemberSelectTree) {
+            return ((MemberSelectTree)expr).getStartPosition();
+        }
+
+        final Tree rightMostExpr = expr.accept(new SimpleTreeVisitorES5_1<Tree, Void>() {
+            @Override
+            public Tree visitAssignment(final AssignmentTree at, final Void v) {
+                return at.getExpression();
+            }
+
+            @Override
+            public Tree visitCompoundAssignment(final CompoundAssignmentTree cat, final Void v) {
+                return cat.getExpression();
+            }
+
+            @Override
+            public Tree visitConditionalExpression(final ConditionalExpressionTree cet, final Void v) {
+                return cet.getFalseExpression();
+            }
+
+            @Override
+            public Tree visitBinary(final BinaryTree bt, final Void v) {
+                return bt.getRightOperand();
+            }
+
+            @Override
+            public Tree visitInstanceOf(final InstanceOfTree it, final Void v) {
+                return it.getType();
+            }
+
+            @Override
+            public Tree visitUnary(final UnaryTree ut, final Void v) {
+                return ut.getExpression();
+            }
+        }, null);
+
+        return (rightMostExpr instanceof MemberSelectTree)?
+            rightMostExpr.getStartPosition() : -1L;
+    }
+
+    // return if the given String is a valid identifier name or not
+    private boolean isIdentifier(final String test) {
+        if (test.isEmpty()) {
+            return false;
+        }
+
+        final char[] buf = test.toCharArray();
+        if (! Character.isJavaIdentifierStart(buf[0])) {
+            return false;
+        }
+
+        for (int idx = 1; idx < buf.length; idx++) {
+            if (! Character.isJavaIdentifierPart(buf[idx])) {
+                return false;
+            }
+        }
+
+        return true;
+    }
+}