These are chat archives for jdubray/sam

Jun 2018
Janne Siera
Jun 22 2018 08:33
@jdubray I thought you might be interested in this:
One of the authors also left a comment in this thread:
Here's his/her comment:

That's pretty accurate! (I'm one of the authors.)
In event-based programming, one of the basic abstractions are something variously called "events", "futures", or "promises". The idea of a future is that it is a data structure that can yield a value at some point in the future, but not might be ready to produce one right away. This idea dates back to (at least) MultiLisp and the Connection Machine, but many modern languages support this primitive -- for example, Javascript, Rust, Ocaml, C#, Java and Scala all have good library support for it.

Our basic idea is that futures correspond very closely to the interpretation of the "eventually" operator in temporal logic. So if we could give a typed lambda calculus for temporal logic, then we could implement the eventually operator with futures. The benefit of doing this is that we could design languages which combine the easiness of reasoning featured by purely functional programming, while still offering good support for event-based programming (eg, for GUIs). In addition, if we are coming from a typed language that has enough invariants, we can also simplify the implementation of futures (since we know statically that certain problems like deadlock can't arise).

My personal goal is to figure out the fundamental primitives of interactive programming. Ultimately I'd like to be able to go from a framebuffer to a comfortable GUI toolkit in a few hundred lines of code, so that teaching the principles of how to implement these things can fit into a semester-long course. (Since there is a fairly small limit on how much code a student can reasonably write/comprehend in a term, the better we understand a problem the more we can teach.)