Frame Context

I was not there, but I suspect new programming languages are preceded by new ways to think about programs. The distinction between code and data inspired opposing viewpoints supported by Lisp in opposition to C++. Lisp treated code as data, and C++ bundled code with data. A more literal use of the word function led to functional languages. To deal with concurrency, I find myself examining the mechanics of functions. A function is implemented as a frame on a stack. Threads and processes are implemented as context in a circular buffer. I believe the first step toward concurrent functions is to blur the distinction between frame and context. Functions can (re/en)-queue themselves or each other to a circular stack. C++ made the "this" pointer common to its member functions. Similarly, I'd make a sequential state a standard argument to each function on the circular stack. The return value of functions on the circular stack indicate how or whether to re-queue the function. Thus, using the standard argument, a function could pick up from where it last retuned. To promote mix-and-match functions on the circular stack, each function on the circular stack is actually a cluster of functions, re-queued as a cluster, and advanced one to the next with another return value. Thus, the standard argument indicates intra-function location, and the progress through the cluster indicates inter-function location. User specified arguments to the cluster of functions are (re/en)-queued to per-type circular buffers. Tagged arguments allow arguments to be shared between functions on the circular stack. Function clusters have a standard argument called a layer that can be changed during the function invocation, is retained for re-invocation, and copied for new clusters. Thus, function clusters are collected into layers with the same initial layer standard argument. Often, they layer standard argument is used as a tag to share arguments across the layer. This permits a function to en-queue a cluster with one component specified as a function that uses the layer's arguments in addition to the arguments shared by the cluster components.