Slate has a concatenative syntax
Sat, 10 Jun 2000 13:08:19 -0700
NOTE: this has been cross-posted to 3 mailing lists. Keep that in mind if
Some of you fellows are from the Tunes list, so you have heard a little of
this language. The language is pretty basic... objects are namespaces that
sit in a graph, with the (unidrectional) connections representing either
slots in the objects or names within namespaces, depending on your perspective.
Slate expressions are just concatenations of lookup directives (i.e. name
the next object in the chain and you're there). So there's a namespace
stack to follow evaluation of expressions. There's exactly one special
syntax operator, and it pops the namespaces off of the stack and causes
evaluation. For our first round at creating an environment, the system will
be much like a hierarchy, with "<" slots forming the basis for obtaining
other objects. Note that this doesn't pop namespaces off the stack, it just
causes the expression's path to double-back. Executable code is possible
because the object model supports inheritance of behavior and a data-flow
model between slots. The initial system is sticking with ":" slots for
assignment and "^" (read "result"). There is also a very powerful
meta-object system being worked out, but this will also take time.
There's an old (and broken) tutorial at
http://www.tunes.org/~water/slate-tutorial.html, but at least the syntax of
the example expressions has been properly updated. (Slate was applicative
in syntax for quite a while.) I'm rebuilding the tutorial at
Too much is changing too quickly for me to keep all my documentation
properly consistent, so please bear with me. This is also why I have been
so secretive about the development process, since it would wind up
confusing the vast majority of people without good reason.
Absolutely everything is at the level where the user can work with. Even
the "." operator will be available for modification once the compiler is
ported to Slate in terms of meta-objects and such.
I promised language definition at least a week ago, and it was ready to go
at that point, but I have had my hands full with my job and with getting
the documentation system ready.
The Slate language old documentation is at
http://www.tunes.org/~water/slate-home.html but this will soon be replaced
by the contents at http://diktuon.arrow.cx. There's a lot of new content
there, and some re-written and revised Tunes work. The linking system is
not online just yet, though, so it's not simple to navigate. The system
will be re-usable for many projects.
Anyway, I'm in the process of opening up this project, since we are
reaching some very definite and practical specifications, instead of the
general guidelines we had before.