I could not possibly agree more with this view of teaching software/CS.

We are focused on introductory programming education at a high-school and collegiate level — what is often called “CS 1” and “CS 2” (roughly, the first year of college). Pyret is being actively used in everything from high-schools to upper-level collegiate courses, giving us a tight feedback loop.

Of course, even in that setting there are differences of opinion about what needs to be taught. Some believe inheritance is so important it should be taught early in the first semester. We utterly reject this belief (as someone once wisely said, “object-oriented programming does not scale down”: what is the point of teaching classes and inheritance when students have not yet done anything interesting enough to encapsulate or inherit from?). Some have gone so far as to start teaching with Turing Machines. Unsurprisingly, we reject this view as well.

What we do not take a dogmatic stance on is exactly how early state and types should be introduced. Pyret has the usual stateful operations. We discussed this at some length, but eventually decided an introduction to programming must teach state. Pyret also has optional annotations, so different instructors can, depending on their preference, introduce types at different times.

I’m delighted to see work on languages like Dr. Racket and Pyret, and the more so because the teams behind both have been willing to set aside many of the dogmas of how CS has been taught and actually do pedagogical research. Also: OOP is a useful tool, but I’m with them: treating inheritance as a first-semester concept is… nutty.

The whole “Why Pyret?” page is worth reading if you have any interest in programming languages or teaching software development and computer science.