WalnutDoc.tioga
Willie-Sue on July 9, 1990 11:41:16 am PDT
Subhana Menis, April 28, 1987 11:23:18 am PDT
(Christian Jacobi, August 23, 1993 12:06 pm PDT)
HOW TO USE WALNUT
HOW TO USE WALNUT
CEDAR 7.0 — FOR INTERNAL XEROX USE ONLY
CEDAR 7.0 — FOR INTERNAL XEROX USE ONLY
How To Use Walnut
Willie-Sue Orr
Release as [Cedar10.1]<WallTapestry>WalnutDoc.tioga
© Copyright 1983, 1984, 1985, 1986, 1987, 1988, 1989, 1993 Xerox Corporation. All rights reserved.
Abstract: Walnut is a computer mail system interface that runs in Cedar. It provides facilities to send and retrieve mail (using the Grapevine mail transport system), and to display and classify previously retrieved messages. This document describes how to use Walnut; the document WalnutInterfacesDoc.tioga gives information about programmer access to a Walnut database.
How to Use Walnut: Contents
0. Introduction
1. Becoming a user
2. Database structure
3. User interface
4. The log
5. Coping with releases and crashes
6. User profile options
7. BlackCherry and Walnut
8. Shortfalls and wishes
[If you are reading this document on-line, try using the Tioga Levels menus to initially browse the top few levels of its structure before reading it straight through.]
XEROX   Xerox Corporation
    Palo Alto Research Center
    3333 Coyote Hill Road
    Palo Alto, California 94304
For Internal Xerox Use Only
0. Introduction
Walnut is a mail system that runs in Cedar. Walnut provides facilities to send and retrieve mail (using the Grapevine mail transport system), and to display and classify stored (i.e. previously retrieved) messages. Walnut uses the Cypress database system to maintain information about stored messages.
1. Becoming a User
First, get the latest Walnut (Bringover -mp Walnut, usually into the release/commands subdirectory). This will also retrieve WalnutSend, Cypress, AlpineUser, and various programs for printing. These latter files will be also loaded by Walnut as needed.
Before you can run Walnut, you will also need an account on some Alpine server to store your Walnut files. If you're in Palo Alto, contact Sharon Johnson <SJohnson.ap> or Willie-Sue Orr <Willie-Sue.pa> to obtain an Alpine account; say you are using Walnut and that person will create the files necessary to run Walnut and make sure your log files get backed up. In other areas, contact your local Alpine Administrator.
Edit your personal profile to contain all of the entries specified in WalnutDefault.profile (openr WalnutDefault.profile).
To start Walnut, type
Walnut
to a CommandTool. This will load lots of files, but finally a Walnut control viewer will appear.
You can include Walnut in a checkpoint. Be sure not to click checkpoint until the message "...Ready" appears in the Walnut control viewer typescript. Message and Message set displayers get updated after each rollback; if a displayed message or message set has since been deleted, the viewer will be destroyed.
Walnut now has the capability of looking at several databases at once, provided the internal name and number identifying each such database is different. All the public databases are defined appropriately and are different from the standard <name, number> for personal mail databases. These numbers appear in the root file which defines the Walnut database. The current reserved values are:
<Icons, 140B>
<Walnut, 200B>
<Nuthatch, 250B>
<Finger, 260B>
<Test, 300>
<Whiteboard, 310>
<Tool, 320>
<WalnutSortDef, 330>
[330B..350B) for the folks in Pasadena
These <name, number> pairs are known to Cypress itself.
[201B..250B) are reserved for public databases. Other numbers are fair game. OpenR NewWalnutUserDoc to see how to create other walnut databases.
To keep track of which msg and msgSet displayers go with which control window, a number in parentheses will appear to the left of the various names in the caption; the only one which does not have a number is the one invoked by typing simply Walnut (usually one's mail but not necessarily). It is STRONGLY urged that a user have only one Walnut database set up to retrieve mail (one can have only one of these running at one time). The screen quickly gets very confusing.
The feedback for WalnutSend stays with the first Walnut invoked, until that control window is destroyed; then it goes to the next, or to its own typescript viewer if there is no control window.
2. Database Structure
We begin with a user's model of Walnut's database. Walnut's database contains two entity types: message and message set.
A message entity corresponds to a message retrieved from the Grapevine mail transport system. Like all database entities it has a name, consisting of the unique message ID provided by Grapevine, expressed as a ROPE of hex characters. A message also has several immutable properties: its sender, its subject, and so on. Its unread property is a BOOL whose value is TRUE when the message is first stored in the database, and is set to FALSE when the message is first displayed.
A message entity is also a member of one or more message sets. A message set entity is named by a text string containing no embedded blanks. There are two distinguished message sets: Active and Deleted. A newly-retrieved message is made a member of Active. A message that is removed from all other message sets is added to Deleted. Using the Active and Deleted message sets in this way ensures that each message belongs to at least one message set.
Each user will generally have one private Walnut database for reading mail. Additionally, there are public Walnut databases (residing on Alpine servers) that any Walnut user can browse.
See Section 4 for information about access to multiple Walnut databases. You may have either readonly or write access to a public database; if you have write access, then it is possible to move messages among message sets and to delete unwanted messages from the database (by doing an Expunge, as described below).
3. User Interface
Walnut implements four viewer types: the Walnut control viewer, the message set display viewer, the message display viewer, and the message composition viewer. When Walnut is running there is one Walnut control viewer, and any number of instances of the other viewer types. The iconic form of the Walnut control viewer is a mailbox. Anything that can be done with Walnut can be done by starting from the control viewer (sometimes by creating other viewers).
Walnut's user interface attempts to be consistent with conventions used elsewhere in Cedar. Clicking LEFT on a button representing a Walnut entity (a message or a message set) "selects" the entity (makes it an implied parameter to other operations); clicking MIDDLE on such a button opens the entity (displays more information somehow). This is analogous to the behavior of icons in Cedar.
Unless otherwise specified, hereafter "click" means "click with the LEFT mouse button."
3.1 Message sets
The message sets in a Walnut database are represented by buttons in the Walnut control viewer. One can now control the order in which the message set buttons appear, by creating a tioga file that gets loaded into this viewer; every non-comment text string will be made into a button (with duplicate names being the same button as far as Walnut is concerned). If there are names that are not message sets in the database, their buttons appear with a line through them (and clicking on them will not open a message set). To make sure that one can access all one's message sets, the last node of this file is always replaced with a node containing all the message set names. Creating new message sets makes buttons appear in this last node only. When this viewer is in buttoning mode, one has access to one's message sets. To edit this viewer, select Edit msgSetButtons in the popup MsgSetOps menu. After editing, select Save msgSetButtons, and the changes will be saved. There is no Reset. To use this feature, one must have a file named Walnut.MsgSetButtonsFile in the same place as one's walnut root file. If this file does not exist, a local file is used, and only the names of message sets in the old style will appear. See section 3.1.1 for details on getting started (which is tricky).
In the last node, the Active and Deleted message set buttons always appear first; other message set buttons appear in alphabetical order.
Operations on message sets are performed by using menu items on the second line of the Walnut control window; the MsgSetOps menu item in the first menu line will open a popup menu with several selections. Many of the operations in the popup menu use the selected messages sets as implied arguments. Note that for the printing operations, Walnut will load any files necessary.
Database Info gives log length, number of deleted messages, total messages and number of message sets
Size of MsgSet(s) gives number of messages in the selected message sets
Create MsgSet uses the selection to create a new message set (containing no messages). A message set button with this name will appear at the end of the buttons and be selected
Delete MsgSet(s) deletes the selected message sets; requests confirmation if any message set to be deleted contains messages
Make MsgSet(s) Empty removes all the messages from the selected message sets; requests confirmation.
R.O.T. MsgSet (short for RemoveOverThere) takes the primary selection as the root message set. If this message set exists, it removes messages in this root message set from any of the selected (in the Walnut control window sense) message sets. If no message sets are selected, the R.O.T. is performed across the entire database, i.e. upon completion, the messages in the root message set will appear in no other message sets.
Save msgSetButtons or Edit msgSetButtons depends on the state of the message set buttons.
Append Msg to MsgSet(s) takes the selection contents (or the selected viewer if the length of the selection is less than 2), makes a unique gvID for it if necessary and adds it to the selected message sets.
PressPrint prints all the messages in the selected message sets.
Interpress2.0Print prints all the messages in the selected message sets using Interpress2.0.
Interpress3.0Print prints all the messages in the selected message sets using Interpress3.0.
Write MsgSet(s) To File writes the messages in the selected message sets to the tioga file whose name is either the selection or derived from the name of the first message set that was selected.
Write MsgSet TOCs To File writes the TOCs for the messages in the selected message sets to the file whose name is either the selection or derived from the name of the first message set that was selected.
Archive MsgSet(s) provides a way to copy a set of messages into a file that can later be read by another mail system that uses the "PARC standard mail format" (Hardy and Laurel do). 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).
Append MsgSet(s) same as Archive but appends the messages to the given file.
ArchiveAndEmpty archives the messages in the selected message sets and then empties the message sets.
AppendAndEmpty appends the messages in the selected message sets to an existing archive file and then empties the message sets.
ArchiveAndDelete archives the messages in the selected message sets and then deletes the message sets.
AppendAndDelete appends the messages in the selected message sets to an existing archive file and then deletes the message sets.
DisplayMsgFromName takes the current selection as the internal id of a msg and displays the msg, if it exists.
OldMailReaderOptions creates a sub viewer in the control window, with file and msgSet fields to fill in. Clicking DoIt performs the operation. Close destroys the sub viewer. This option allows one to read a Laurel, Hardy or Lafite mail file, or a file created by Walnut's Archive operation. If you do not specify a msgSet name, the messages will be put in Active. If the specified message set does not exist, it will be created. Using the old mail reader to read a Walnut archive log will put the messages back into the message sets from which they were archived.
Printing Options creates a sub viewer in the control window, to allow multiple copies or the chance to use a server other than the default. Fill in either of these fields before clicking Options, which gives another popup menu with the choices:
Msg print the message in the selected viewer (if it is in the database managed by this control window).
SelectedMsgInMsgSet(s) print the selected message (if any) in each of the msgSets selected in the control window.
MsgSet(s) print the selected msgSets
MsgSetTOC(s) print the TableOfContents for the selected msgSets
Close destroy the Printing Options sub viewer.
All but the Close option produce yet another popup menu, letting you select which variant of print you want:
PressPrint
Interpress2.0Print
Interpress3.0Print
NOTE: it is up to the user to known what variant to send to which printer.
Finally, the Expunge button destroys all of the messages in the Deleted message set and reclaims the storage (in the database and log) used for these messages (it "expunges" the Deleted messages). You should expunge when the Deleted message set contains a few hundred messages; when Deleted begins to fill up to the point that it takes several seconds to display, it's time to expunge. Expunging is fairly slow.
Change in Cedar10.1: Expunge will expunge the LoganBerry database only, not the log. To expunge the log use the DoWalnutCopact commander command.
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 (the default is to display it in a small, bold font). 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:
MoveTo adds the message from the message set to all of the message sets selected in the control window and deletes it from the message set.
Display displays the selected message.
Delete deletes the message from the message set; if it thus becomes a member of no other message sets, then it is added to the Deleted message set.
AddTo adds the messages to the selected sets.
Places is a subset of the Tioga places menu.
Levels is the Tioga levels menu.
MsgOps provides some less frequently used operations (see below).
The Active message set includes a NewMail button that reads new mail and adds the new messages to the Active message set.
The MsgOps (popup) menu provides the following choices:
Sender builds a Sender window
Size of MsgSet reports the number of messages in this message set
Categories lists (in the Walnut control window) the message sets in which the selected message appears (a message can simultaneously be in several message sets).
size Of Msg reports the number of bytes in the selected msg and indicates if it has Tioga formating or not
gvID of Msg prints the database name for the message in the control window.
Append Msg takes the selection contents (or the selected viewer if the length of the selection is less than 2), makes a unique gvID for it and adds it to the message set as a message.
PressPrintMsgSet prints all the messages in the message set (see WalnutDefault.profile for options).
Interpress2.0PrintMsgSet prints all the messages in the message set, using Interpress2.0 (see WalnutDefault.profile for options).
Interpress3.0PrintMsgSet prints all the messages in the message set, using Interpress3.0 (see WalnutDefault.profile for options).
PressPrintSelectedMsg prints the one selected message (see WalnutDefault.profile for options).
Interpress2.0PrintSelectedMsg prints the one selected message, using Interpress2.0 (see WalnutDefault.profile for options).
Interpress3.0PrintSelectedMsg prints the one selected message, using Interpress3.0 (see WalnutDefault.profile for options).
PressPrintTOC prints the TableOfContents of the message set (see WalnutDefault.profile for options).
Interpress2.0PrintSelectedMsg prints the TableOfContents of the message set using Interpress2.0 (see WalnutDefault.profile for options).
Interpress3.0PrintSelectedMsg prints the TableOfContents of the message set using Interpress3.0 (see WalnutDefault.profile for options).
R.O.T. MsgSet (for RemoveOverThere) removes messages in this msgSet from any of the selected (in the Walnut control window sense) message sets. If no message sets are selected, the R.O.T. is performed across the entire database, i.e. upon completion, the messages in this message set will appear in no other message sets.
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.)
3.1.1 Walnut.MsgSetButtonsFile
The easiest way to get started is to let Walnut do the initial work for you. Start up the version with this feature, then quit. Do a list of ///your-alpineserver-name*. You will see a file named something like []<>Ebbetts.alpine>Willie-Sue.pa>Walnut.MsgSetButtonsFile. Open this file and you'll see one node with all the message set names in it. Edit the file as you like, remembering that the last node in this file will always be replaced when Walnut starts up. Save the file. Then copy the file to your alpine server, using the local name to tell you where to put it (you'll have to do some editing on the name), e.g.
copy [Ebbetts.alpine]<Willie-Sue.pa> ← []<>Ebbetts.alpine>Willie-Sue.pa>Walnut.MsgSetButtonsFile.
Future edits can all be done through the Walnut control window.
3.2 Messages
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 (it will be destroyed when the control window is destroyed).
Answer creates a Walnut Send viewer initialized with a proper heading for an answer.
Forward creates a Walnut Send viewer initialized either with a copy of the message for forwarding.
ReSend creates a Walnut Send viewer initialized with a copy of the message, with the Date: field changed to Original-Date:, any Sender: field changed to Original-Sender: and any From: field changed to Originally-From:.
MsgOps gives a popup menu, with the following selections:
Sender creates a Sender viewer.
Categories lists (in the Walnut control window) the message sets in which the selected message appears (a message can simultaneously be in several message sets).
AddTo adds this message to the message sets selected in the control window
Remove From ... shows in a popup menu which message sets this message belongs to; selecting one of these removes the message from that message set.
SizeOf types the byte count for text only in the control window
gvID types the gvID of the message in the control window.
PressPrint print the message using Press.
Interpress2.0Print print the message using Interpress2.0
Interpress3.0Print print the message using Interpress3.0
MakeEditable allows one to play with fonts in teh displayed version of the message; makes no changes in the stored version of the message
Split, Places and Levels buttons are from Tioga.
3.3 Sending mail
To create a Walnut Sender, left-click Sender in the Walnut control viewer, or use the Answer or the Forward button on a message viewer: one can also get a Sender by typing WalnutSend to a command tool, or selecting the Sender option in the MsgOps menu of a MsgSet displayer or of a Msg displayer. A Walnut Sender is a Tioga viewer for typing in the header fields and body of a message you want to send.
WalnutSend will save copies of the messages you have sent. The profile option:
WalnutSend.OutBoxLength: number (defaults to 1)
specifies how many to save. Setting this option to 0 (or some negative number) will save all the messages that have been sent, but the the popup menu will show you no more than 25. The others would be available for postmortems. See Forms below.
The Sender menu:
Send is well named. StopSending! pops up during part of the sending process; clicking it gives you a last-minute chance to change your mind about sending a message. Right-clicking Send makes the Walnut Sender become iconic after syntax checking. (In iconic form a Walnut Sender is the back of an envelope.) A Walnut Sender will not allow itself to be destroyed while sending is in progress.
SendChecked will warn you if the message to be sent contains comment nodes; if it does, you have the option of sending anyway or quitting.
Get is similar Tioga Get -- Will load a local or remote file and allow editing
Store is like Tioga Store. If you right-click, the viewer will be left in edited mode, so that it won't get re-used.
Save is like Tioga Save. If you right-click, the viewer will be left in edited mode, so that it won't get re-used.
Forms shows the Forms popup menu, which provides three options plus forms supplied by the user.
NewSender creates another Sender.
DefaultForm replaces the current Sender with the default. (You can specify a non-standard default in your User.profile.)
Previous Msg if your outBox has only one message, that will get stuffed into the Sender; otherwise you'll be given a popup menu of selections.
You specify your own forms (see below).
Get and Store change the name of the Sender to be the file name. Clicking the Forms items will cause any backing file association for the Sender to be cleared and the caption will revert to Walnut Sender.
Split is the Tioga Split.
Places is the Tioga Places.
Levels is the Tioga Levels.
The default Sender form has node structure and uses a small bold font (looks) for the header fields. Added header fields use the same looks; to get added fields to have some other looks, include in your User.profile the key WalnutSend.MsgHeadersLooks, set to whatever you like.
If you want to change the default forms, you can create your own and specify them in your User.profile with the entries:
WalnutSend.DefaultForm: filename
WalnutSend.AnswerForm: filename
WalnutSend.ForwardForm: filename
The answer form must have header lines in the same order as the standard form and provide placeholders in the appropriate header positions. The forward form must have a node with the contents "ForwardedMessage"; Forward replaces this node with the message being forwarded. These private defaults can be local or remote.
If you need additional sending forms, you can specify them in your User.profile with the entry:
WalnutSend.MsgForms: {list of file names}
These additional forms will then appear in the pop-up Forms menu. Like private defaults, these additional forms can be local or remote. (You might, for instance, want to specify remote forms from /Cedar/CedarChest®/Top/Forms.df.) Only the short name pops up; the default extension is .form, and only non-default extensions pop up. At the moment, there is no way to create additional answer or forward forms.
A message to a public distribution list or to more than ten individuals probably needs a Reply-to: field. If your message doesn't contain one, Send will show 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
WalnutSend.ReplyToSelf: TRUE
in your User.profile. (With this entry, if at some point you want Reply-to: all you have to insert it by hand.)
WalnutSend will use a (local or remote) file as a private distribution list. To invoke this feature, put the file name, followed immediately by ":;" (colon semicolon) in the To: or Cc: field. The file format is quite restricted; anything up to a colon is ignored; the addressees must be separated by commas, and parsing terminates at the first semicolon or end of file; no CR's are allowed. A default extension of .dl is assumed.
Watch the Walnut control window for errors in transmission. If the transmission is successful, the message is saved and a new default form appears.
WalnutSend will also run standalone, in which case it creates a small typescript viewer for reporting progress, errors, etc.
3.4 Retrieving mail
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 mail is retrieved from grapevine and stored on the user's newMailLog on Alpine. The Walnut control viewer will then display a message like
You have new mail at May 28, 1985 6:13:43 pm PDT
(if you are reading a public database, the message will simply be
Cannot retrieve mail using this database (if you have write access) or
You only have Read access to this database).
If the control window is iconic and there is new mail, the flag on the icon is raised.
Left-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 into the database. The new messages appear as buttons at the bottom of the Active message set viewer, displayed with the looks to be used for unread messages. If you right-click NewMail in the control window, Walnut will check for mail on grapevine.
Walnut will automatically copy the new mail from the newMailLog and add it to the database for you. 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 on grapevine, even though the status line says there is; it should take Walnut about one minute to do the automatic retrieve, unless some long running operation is in progress or there is lot of mail.
3.5 Queries
OpenR WallabyDoc for details.
3.6 Global operations
The main menu of the Walnut control window provides the following buttons:
Sender creates a WalnutSend viewer
NewMail retrieves mail from the newMailLog
CloseAll button furnishes a quick way of ending a session with Walnut; it destroys all message displayers, and closes all message set displayers and the Walnut control viewer.
MsgSetOps opens a popup menu (see below).
Find does a Tioga-style find operation on the MsgSetButtons subviewer.
Expunge (guarded) expunges the Walnut database; all messages in the Deleted set disappear without a trace. Without the Expunge operation, the database and log would grow without bound. Section 4 contains more information on this topic and why not to do Expunge.
Walnut registers a few 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 some other walnut database, provide the root file name as an argument (e.g., Walnut [Luther.Alpine]<CSL-Notebook>Walnut.root opens up the database defined by [Luther.Alpine]<CSL-Notebook>Walnut.root). The WalnutScavenge command is described in Section 5. WalnutNewMail simulates clicking the NewMail button. The WalnutSend command is like clicking Sender.
4. The Log
Walnut keeps a record of all retrieved messages and all database updates for a single user in a Walnut log file. This is a text file with a very simple format; you can load your Walnut log into a Tioga viewer to see this.
The important point is that the truth about your Walnut mail resides in a Walnut log file; the Cypress database that Walnut uses for query processing can always be reconstructed by replaying a Walnut log file. The Walnut log mechanism is robust, making Walnut's mail storage reliable even if Walnut (or some other part of Cedar) crashes.
Walnut uses several log files. The current log is the one on which messages are stored and the database updates recorded. The expunge log is the log written when an expunge is performed (this log becomes the current log when the expunge completes). The new mail log is used to copy new messages from the Grapevine servers; a separate log is used so that mail retrieval can be performed simultaneously with normal operation. When the user does a NewMail operation, the contents of the new mail log are copied to the current log. Finally, the read archive log is used to copy the contents of Walnut archive files (when performing a WalnutOldMailReader operation); a separate log is used here to ensure that the current log is changed only if the archive file can be successfully read and parsed. (Note: currently all of these files must reside on the same Alpine server in the same directory/subdirectory.)
To provide a connection among the various log files (and the Walnut database), a Walnut root file is used: the root file contains the names of the various log files, the name of the database file, and additional information (like the Grapevine RName of the user who may retrieve new mail for this database). Walnut locates the root file for a particular user by consulting the Walnut.WalnutRootFile entry of the user profile; if there is no such entry, the name "[Luther.alpine]<UserName.registry>Walnut.Root" is assumed. Type openr Template-Walnut.root to see a sample Walnut.Root.
5. Coping with Releases and Crashes
Walnut sometimes crashes because its database has gotten into a bad state. Also, a new release of Walnut or the Cedar database system will occasionally change the database format that Walnut understands. From Walnut's point of view these circumstances are very similar.
A Walnut database can always be reconstructed by replaying a Walnut log file. If Walnut is not loaded, you can reconstruct the Walnut database by executing the command WalnutScavenge; this will rebuild the database from the log file, and leave Walnut running when done. Even if Walnut is already loaded, you can scavenge by typing WalnutScavenge to the Executive. Walnut will also scavenge automatically if the database cannot be found, or force you to Scavenge or Quit, when it finds incompatiblities in schema date or internal representation.
6. User Profile Options
Openr WalnutDefault.profile
for the complete list of Walnut and WalnutSend profile options.
7. BlackCherry and Walnut
Now one can create BlackCherry mailLogs from Walnut msgSets. In its simplest form, one has a running Walnut; the command BlackCherryFromWalnut will build a BlackCherry mailLog for each selected msgSet (or for all msgSets if none are selected). The name of the log is msgSetName.mailLog, in the current working directory. BlackCherryFromWalnut uses the Walnut typescript and gives details and progrss reports as it writes the files.
8. Shortfalls and Wishes
What follows is a listing of known deficiencies and contemplated extensions to Walnut. Nobody guarantees that everything listed below will be implemented. But the list does indicate some directions for future work, and may provide context for your own Walnut wishes. Send both bug reports and wishes to WalnutSupport^.
7.1 Message sets
It would be nice to allow selection of more than one message in a message set (perhaps even spanning message sets).
7.2 Retrieving mail
Now that 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"). See WalnutSortDoc for one way to do this.
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.
7.3 Sending mail
It should be possible to forward or answer multiple messages. This requires 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 Sender 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.