cvs-version

     NEW VERSION OF EXPECT, AND VERSION CONTROL.
     ===========================================
     (March 24 99)


We want to begin maintaining Expect and related sources under version
control, and have begun maintaining a new version of Expect to use as
the base version. It's not ready yet, but when it is We hope that you
will use this version and use the version control program (CVS) to
incorporate your specific changes to this version. Here are preliminay
details on how to do that and what to expect from the new version.

We cover:
1. Where to find the preliminary new version of Expect
2. How is it different from the current/ version and how will that
   affect you?
3. How to use CVS to make changes in the new version
4. Plans for this version


1. Where to find the preliminary new version of Expect

For now it's in /nfs/isd/blythe/release/expect. We will try to get
a new volume on nitro for it.

2. How is it different?

It has a preliminary version of the new result-types for nodes, that
allow us to record error information and empty sets without using NIL
for either. Some examples are on the next sheet.


2b. How will that affect you?

If you need to update an old domain to the new version, be aware of
these changes:

Every node that used to have an EDT in its result slot now has an
eresult structure. You can access the value with
(get-eresult-edt (get-node-result <node>)).

Your primitive functions may have to deal with empty sets in a different
way. For example, "primitive-add-numbers" must now give the result 0
on the input "(no (set-of (inst-of number)))" (meaning the empty set of
numbers).

Files with more details on the structures and edts involved:
ps/results.lisp
shared/edts.lisp


3. How to use CVS:

CVS has many options and commands. Here are four simple commands you can 
use to check out a copy of expect, edit it, check that you have no
conflicts with someone else's edits and then add your changes to the
main version. For more info see the man pages, or the texinfo files
at /local/info/*.


The current repository is at /nfs/isd/blythe/cvsroot (again, we'll
change this to a new volume).

So you need to set the environment variable CVSROOT:

% setenv CVSROOT /nfs/isd/blythe/cvsroot

Then you can check out expect in some directory with

% cvs checkout expect
 (makes a copy in your directory, currently about 5 megabytes)

Edit the files as usual.

You can see differences between your version and the repository with

% cvs diff

You can make "updates" if someone has changed the repository since you
edited with

% cvs update

When there are no such changes, or you have updated, you can commit your 
changes back to the main version with

% cvs commit

- It will open an editor for your short comments on the version change,
or you can specify these in a string with the -m option.



For more details, including branches, rollbacks and symbolic tags, 
see the man pages and the texinfo files.


4. Plans for this version:

We hope to incorporate changes people have made to expect using the
version control, for instance:
- fixes from HPKB year 1
- additions to the compiler
- natural language "editor"
- changes for the KA system

We also want to put the other parts of the Expect system under 
the same version control:
- the java ui client and server
- cl-http