Language Design

James Noble

Ever Onward!

EVER ONWARD — EVER ONWARD!
That’s the spirit that has brought us fame!
We’re big, but bigger we will be
We can’t fail for all can see
That to serve humanity has been our aim!
Our products now are known, in every zone,
Our reputation sparkles like a gem!
We’ve fought our way through — and new
Fields we’re sure to conquer too
For the EVER ONWARD I.B.M.

Keeping up the blog has not been one of our strong points, but we have been making some progress in the last few months. We’ve been working our way through a review of Grace’s design and specification, with a few nontrivial changes:

  • Classes create methods, rather than objects, so no longer have “dots” in their name
  • Calling methods in superclasses relies on aliasing, not “super requests”
  • Traits support stateless reusable components
  • A simpler inheritance model that supports classes inheriting from multiple traits
  • Replacing variadic methods with primitive sequences

We expect to describe these changes in a few blog posts soon, as we are working through a thoroughly revised specification.  We plan to release the specification and implementations around the end of February,  for feedback from the community. We then plan to hold workshops (as we did in 2011) to go over what we hope will get getting close to a 1.0 version of the language design. So: Onward! Ever Onward!

Andrew P. Black

A Graceful Summer

I (Andrew Black) have spent a large part of the summer teaching an introductory programming course to a small-ish group of post-bacc students. This was part of PSU’s “New Beginnings” program, which is designed to prepare students who have a bachelor’s degree in some other subject (history, accounting, chemistry, soil science, music …) to enter into our MS program. New Beginnings is intended to be very intensive: students spend 16 hours a week in the classroom, split between two subjects (discrete math and programming, in the case of this summer), plus another 8 hours in labs, plus homework.

My goal for the summer was to lead the students to roughly to the point that an undergraduate would reach after our three-course introductory programming sequence. This turned out to be a stretch goal for those who had never programmed before, but quite reasonable for those students who had a little background.

I never cease to be amazed at the variety of learning styles, even in a cohort of just 11 students. Some are happy to experiment, while others would have really benefited from a Graceful Data Structures book for the latter part of the course. We used Kalicharan’s excellent “Data Structures in C”, and my original plan was to just re-write the programs in Grace. That didn’t actually work out, because a C-based text has to emphasize things that are irrelevant in Grace, and a Grace text will need to talk about stuff that is irrelevant in C — primarily object structure. Still, the basic programs are parallel; I invite you to take a look at binary trees.

James Noble

Grace at ECOOP

The European Conference on Object-Oriented Programming starts tomorrow, and Grace people will be there.

On Wednesday, the first day of the full conference, we’ll present the technical paper Graceful Dialects by Michael Homer et al describes how Grace supports dialects using lexical scope, pluggable checkers, and Grace’s flexible syntax, but without requiring macros or depending on types.

At workshops held earlier in the week, Tim Jones will talk about TinygraceA Rational Reconstruction of the Escrow Example — rewriting everything in Grace always being perfectly rational — both at the Formal Techniques for Java-like Languages workshop on Monday,

And at IWACO on Tuesday, James will present On Owners as Accessors with some examples, at least, tending towards Grace.