The message sets in a Walnut database are represented by buttons in the Walnut control viewer. The Active and Deleted message set buttons always appear first; other message set buttons appear in alphabetical order. There may be several rows of these buttons.

Operations on message sets are performed by using menu items on the second line of the Walnut control window; the MessageSetOps menu item in the first menu line will "open" the second line up for use. To create a new message set (containing no messages) select its name in some viewer, then click Create (in the second control window menu line). A message set button with this name will appear and be selected. Most of the other in the second menu line use the selected messages sets as implied arguments for the operations. To delete one or more existing message sets, select the message sets and click Delete. Note that you cannot delete the Deleted message set this way; you must click Expunge to do that. Walnut requests confirmation if any message set contains any messages. If you delete a message set containing messages, the messages are deleted from the set (as if clicking each message with CTRL-LEFT as described below) before the set is destroyed. To find out how many messages are currently in the selected message sets, click SizeOf; the sizes are printed in the typescript at the bottom of the control window. Clicking Print will print the messages in the selected message sets, loading the TSetter if necessary (see section 6 for printing options).

To create a message set display viewer, click MIDDLE on the corresponding message set button of the control viewer. The iconic form of a message set displayer is a stack of envelopes.

The message set displayer contains a one-line button for each message in the set. Each message button looks much like a line in the top window of Laurel: it shows the date of the message, the name of the sender (or To: field if the sender is the current user), and the message subject. At most one of the message buttons in a set is selected (shown with a grey background). To select a message, click LEFT on it; to select and display a message, click MIDDLE on it. To delete a message from the message set, click CTRL-LEFT on it; its button will disappear. (Note that if this message belonged to no other message set, it is added to the Deleted set, and hence is still accessible.)

A message set displayer also contains several command buttons that operate on the selected message:

For the MoveTo, Delete, and AddTo buttons, LEFT-clicking simply performs the operation described above, while RIGHT- or MIDDLE- clicking performs the operation and displays the next message in the set. (Note that if you have readonly access to a public database, then the MoveTo, Delete and AddTo buttons will not appear in message set displayers.)

As described above, a message can be displayed by clicking MIDDLE on a message button of a message set displayer. This creates a message display viewer, whose iconic form is an envelope (clicking SHIFT-MIDDLE on a message button causes the created viewer to fill the entire column). The message within such a viewer is not editable. This viewer is associated with the message set that created it, so clicking MIDDLE on another message of the same message set shows this new message in the same message displayer. This is designed to avoid a proliferation of message displayers. Of course, there are times when you really want to create viewers on several different messages in one set. Clicking a message displayer's Freeze button (which then disappears) permanently binds the message to the message displayer. If all message displayers for a given message set are frozen, then MIDDLE clicking in the message set creates a new displayer. A frozen message displayer cannot be unfrozen, but can be destroyed.

A message displayer has several other buttons. The Categories button is the same as that on message set displayers. Answer and Forward create a Walnut Send viewer initialized either with a proper heading for an answer to the message or a copy of the message for forwarding. The Print button uses the TSetter to print the message -- it will load the TSetter if necessary. And the remaining Split, Places and Levels buttons are from Tioga.

To create a Walnut Sender, left-click NewForm in the Walnut control viewer, or use the Answer or the Forward button on a message viewer, or type WalnutSend to the User Exec. A Walnut Sender is a Tioga viewer for typing in the header fields and body of a message you want to send.

The Sender menu:

The default Sender form now has node structure and uses a small bold font for the header fields. But added header fields use standard Roman; to get added fields to use the small font, include in your User.profile the line:

If you want to change the default forms, you can create your own and specify them in your User.profile with the entries:

If you need additional sending forms, you can specify them in your User.profile with the entry:

A message to a public distribution list or to more than twenty individuals probably needs a Reply-to: field. If your message doesn't contain one, Send will pop up a menu with the items Self, All, and Cancel. Self means insert the Reply-to: field and fill in my name; All means do not insert a Reply-to: field (replies then go to the full list); Cancel means whoops, don't send the message yet. To get Reply-to: sender when appropriate, without being asked, insert the entry

Watch the Walnut control window for errors in transmission. If the transmission is successful, the message is saved and a new default form appears.

Walnut polls the mail servers at regular intervals. If there is new mail for the logged-in user and the database being read is the user's private database, the Walnut control viewer displays a message like

Clicking the NewMail button (which will not be present if you're browsing a public database) in either the control viewer or the Active message set viewer retrieves all the new mail. You can "button ahead" during message retrieval. The new messages appear as buttons at the bottom of the Active message set viewer, with a "?" in the leftmost column of each new message button to show that the message is unread. If the control window is iconic and there is new mail, the flag on the icon is raised; for convenience, there is a NewMail button in the Active Messages displayer, which will retrieve the waiting mail.

Walnut will now automatically retrieve new mail for you, when it knows that your mailbox is not empty. To enable this feature, include:

Walnut.AutoNewMail: TRUE

in your profile. During startup or restart, Walnut may not immediately notice that there is new mail, even though the status line says there is; it will take Walnut at most 5 minutes to do the automatic retrieve. You can, of course, still use the NewMail buttons.

The Walnut control viewer has a few more buttons that will now be described. There is a profile option, Walnut.DoAutoCommit (defaults to TRUE), that does a commit after each Walnut action. With this feature disabled, a Commit button appears. Clicking Commit commits all changes that you have made to Walnut's database. The only other operations that automatically commit database changes are Destroy and CloseAll. If you perform a Walnut operation that updates the database and then boot or rollback without doing a Commit, the effects of that operation are in the log and will be performed on the database and then committed when you next run Walnut.

The CloseAll button furnishes a quick way of ending a session with Walnut. CloseAll destroys all message displayers, and closes all message set displayers. Then it executes a Commit and closes the Walnut control viewer.

The Archive button (in the second control window menu line) provides a way to copy a set of messages into a file that can later be read by either Walnut or Laurel. Select a filename in some window and click Archive. All messages in the currently selected message sets are copied to the named file (if the file name has no extension, ".ArchiveLog" is appended to the name). If Append is clicked, the messages are appended to the named file.

Clicking the (guarded) Expunge button (in the second control window menu line) expunges the Walnut database: all messages in the Deleted set disappear without a trace. (Laurel purges deleted messages every time you Quit or change mail files.) Without the Expunge operation, Walnut's database and log would grow without bound. The Expunge operation may fail if your disk is nearly full; this is a motivation for regular Expunges. Section 4 contains more information on this topic.

If you shift-click (twice) the Expunge button, it will describe where in the log file the next expunge will begin, and how many bytes and pages of the log will get read.

Walnut registers several infrequently-used commands with the Cedar Executive. All of the command names contain the prefix "Walnut", so typing Walnut*? to the Executive enumerates them. The Walnut command creates a Walnut control viewer if you should happen to Destroy yours; to open a public database on Alpine provide the Alpine directory name as an argument (eg., Walnut CSL-Notebook opens up the database stored on [Luther.Alpine]<CSL-Notebook>Walnut.segment). The WalnutExpunge command has the same effect as RIGHT-clicking Expunge. WalnutDump writes on expunged version of the log on the file "///Walnut/UserName/Walnut.TempLog", but makes no database changes. The WalnutOldMailReader command is described in Section 3, and the WalnutScavenge command is described in Section 4. WalnutNewMail simulates clicking the NewMail button. The WalnutSend command is like clicking NewForm. WalnutScavenge is discussed in Section 5.

It would be nice to allow selection of more than one message in a message set (perhaps even spanning message sets).

It seems desirable to make mail retrieval a continuous background activity. This would tend to insulate users from the response time of Grapevine.

Once mail retrieval is implemented in the background, a natural next step is to provide some means for a user procedure to classify incoming mail according to its significance, file it in sets other than Active, let the user know the status of his new mail ("You have important new mail").

The procedure that stores new mail in the database should understand the In-Reply-To relationship. Eventually, users should be able to write queries or other commands that exploit this relationship.

It should be possible to forward or answer multiple messages. This seems to require the ability to select multiple messages.

When sending a sequence of messages with the message composition viewer, you tend to click Send, wait for the feedback "sending ...", then make the viewer iconic (to reclaim the screen area) and finally click NewForm to create a new viewer. It would be smoother to reuse the same message composition viewer, but without waiting for the message to be sent (since this can take quite awhile). Since it is quite unusual to have two messages in transit (as contrasted with two messages being composed) at the same time, this can be achieved by passing responsibility for the message from the message composition viewer to the Walnut control viewer when message parsing is complete, and clearing the composition viewer for reuse. Any errors in transmission would be reported in the control viewer rather than the composition viewer.

Walnut needs a way to make queries. (This is what databases are all about!) For starters, we'd like to have something analogous to Laurel's SearchMail program for performing text pattern matching in the messages of a message set.

The Walnut Expunge operation currently requires more resources (such as disk space) than Walnut requires to perform other operations on the same database. This is unfortunate, since it means that a user can get stuck in a situation where he must hand-edit his Walnut.DBLog in order to recover.