Augusta: An open source Ada 2012 compiler (someday?)

[Peter Chapin <PChapin@vtc.vsc.edu>]

In another thread Shark8 posted a proposal to build an IDE+compiler for
Ada 2012. In his post he notes that having a second open source compiler
offering (besides GNAT) for Ada would be good for the Ada community.

I agree.

GNAT is a fine product but it would enrich the eco-system if there were
alternatives. Accordingly I started a pet project for myself to build an
Ada 2012 compiler from the ground up which I'm calling "Augusta." The
project is here:

    https://github.com/pchapin/augusta

I am not as naive as I probably sound. I fully understand that such a
project is massive and not likely to actually ever be completed.
Fortunately that's not important to me. The project is just a hobby
project and its *real* purpose is to provide me with a source of
entertainment in my off hours. It can fulfill that role perfectly well
even if it never amounts to anything. This situation also frees me to
make design choices that interest me without feeling the need to justify
them rationally. For example Augusta will be written in Scala and will
target LLVM. I choose these technologies because I like them and I'd
like to learn more about them, not because I think they are somehow the
"best" or most logical choices.

I have been planning to announce Augusta's existence to the community at
some point but right now the project is 99% talk and 1% action (at most)
and I had thought to wait until the balance was a little different.
However, Shark8's announcement of his IDE proposal made this seem like a
reasonable time. I support his desire to develop such tools and who
knows... perhaps Augusta can play some role in his project someday.

Right now Augusta is little more than a place holder with some documents
outlining my vision for the project. I have set a release date for
myself of December 31, 2020 in an effort to apply some structure to my
work. My hope is to have something "interesting" done by that time...
although I'm not going to claim it will be full Ada 2012.

In the meantime I've been using Augusta as a source of class examples
and student exercises in a compiler course I'm teaching at Vermont
Technical College. The work there has been in a sub-project called
Allegra which is intended to be a compiler for a series of highly
reduced Ada subsets with increasing complexity. In addition to
supporting my course, my thought was to use Allegra as a kind of
experimentation space for the technologies that will ultimately be part
of Augusta. However, I'm not clear how much, if any, of the methods used
in Allegra would actually transfer to the more complex Augusta project
itself.

Anyway, enough said... I invite anyone who is interested to browse
around in the project. Let me know if you have any questions or comments.

Peter