Just a quick note to remind anyone interested in the desktop
rearchitecture branch, that I post/blog library-related design notes
to the PEAK mailing list at:
http://www.eby-sarna.com/mailman/listinfo/peak
For example, yesterday I wrote up some thoughts about
object-relational mapping with the Trellis here:
http://www.eby-sarna.com/pipermail/peak/2008-February/002862.html
I send these posts to the PEAK list as they are of general interest
to other PEAK users, even though they often cite Chandler
requirements as a driving force in design. (Also, they are usually
unstructured brain dumps of my thoughts, and so less suitable for
posting here. When there are significant new releases, however, I
will usually post announcements here.)
Currently, I'm working on the storage layer for the rearchitecture
branch, specifically investigating ways to map EIM (or "EIM 2")
record schemas onto SQLAlchemy table schemas, and ways to use
SQLAlchemy's mapping strategies for possible semi-automatic
conversion between objects and EIM records. I'm also working on
designing what might be considered an EIM query/update API, to wrap
SQLAlchemy and also serve as a basis for certain kinds of
non-persisted application needs. (For example, displaying generated
recurrence objects that might not be actually stored in the
underlying database.)
The expected programming model for storage will be to define an
application class' EIM schema, and appropriate translation code
(maybe in the form of an SQLAlchemy-like mapping
specification). Thus, all plugins will automatically have a
shareable and dump/restorable schema, since they will need an EIM
schema to work at all. :)
And, as a side effect of having the mapping+EIM schema, it should
then be possible to express queries as Python list comprehensions (or
genexps) in the form of strings, so application level code won't need
to deal in indexes and other such things. Instead, SQL-level
indexing and any other storage-specific optimizations will be
specified via "hints" attached to the EIM schema.
As the specification and design progress over the next few weeks,
I'll be posting the details to the PEAK list. Again, keep in mind
that such postings are highly stream-of-consciousness and shouldn't
be considered official design documents, feature commitments, etc. at
this time. Any "stable" designs, announcements, etc. will still be sent here.
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