ITS version of CLU programming language

[Lars Brinkhoff]

Barbara Liskov's CLU programming language from the 1970s feels
surprisingly modern. It has garbage collection, exceptions,
parameterized types. Files from ITS backup tapes are now available.
The compiler and runtime system runs on PDP-10 emulators.

https://github.com/MITDDC/clu-1976-1989

[sbyr...@gmail.com]

I always liked CLU -- definitely VERY clear distinction on the internal representation of things vs the external.

I'd go further with the parameterized types statements. I believe it's somewhat akin to Go's use of interfaces and its form of protocol-based polymorphism. You define a class ("cluster" in CLU) and you can specify that any particular type that the class is based on (and/or maybe method parameter types, not sure) has specific operations; it is, or can be, more "protocol" based in defining classes; as long as the underlying type has operations x, y, and z (etc) with some specific set of parameter types, you can use it.

Definitely a bit ahead of its time in many ways!

Steve