ZACL is A Concurrency Language

Status: Work in progress
(This website, too, is a work in progress)

UPDATE 2020-05-03: I have been learning and enjoying The D Programming Language quite a bit. It appears to have already achieved much of what I imagined ZACL to be, and it seems likely that ZACL will be defined as a fork of D and implemented with a fork of dmd.

The main points of enhancement I'd like ZACL to offer over D are, ranked by priority:

Improved practical expressiveness,
A built-in "job" type allowing safe, transparent access to threads, processes, coroutines, interfaces,
First-class regular expressions,
The compiler as a .so library, to facilitate run-time code evaluation,
Improved implementation of associative arrays,
Lower compile-time memory overhead (seriously, dmd's symbol table is ridiculous)

No public git repo, yet. I've ditched my old work and have started over with some new D modules.

ZACL is A Concurrency Language. Does the world need yet another programming language? Yes, frankly, it does. Or rather, it will.

Looking at trends in enterprise computer systems, some facts stand out:

The number of cores per processor, processors per server, and servers per cluster, are all increasing. Enterprise computing is performed by vast datacenters filled with multi-core servers, not by individual computers.
Though the amount of memory per server is increasing exponentially with time, it is increasing on a slower exponential curve than processing, storage, and networking capability. Datasets in large ETL systems are increasing in size roughly in proportion to storage and networking capacity. This implies that as datasets grow larger, less physical memory will be available per datum.
Programming language popularity follows a fad pattern. Successful languages will exhibit a protracted period of unpopularity, followed by a rapid rise to prominence, a long or short plateau of ubiquity, and eventually a decline to niche status. The TIOBE graphs of various languages' rise and fall demonstrate this. (A notable exception is C, which has always been and remains very special.)

So, what does this mean for future software development?

Software will be distributed and concurrent.
Software will need to make efficient use of memory.
Software will not be written in the languages we use today.

At the same time, some things will not change:

Rapid development will be necessary, so that problems may be solved and new products/services developed in a short timeframe.
The object-oriented paradigm will remain popular -- even as individual languages rise and fall, the new languages are predominantly object-oriented. It is how software engineers think about software in the 21st century.
The 80/20 rule seems eternal, which is pertinent to code optimization. Low-level optimization involves identifying the 20% of the "inner loop" code which comprises 80% of the runtime, and funneling engineer-hours into making it run faster (e.g., by rewriting it in C or C++).

This tells us what a future programming language needs to look like, and I am using it as a specification for the ZACL programming language, an imperative, object oriented, highly expressive, garbage collected language with a strong/weak static/dynamic hybrid type system, memory-efficient data structure primitives, and powerful tools for distributed and concurrent processing.

I have some practical experience and theoretical education with all of these technologies so I'm trying my hand at putting them together. So far I have most of a formal grammar written up (the expression grammar still needs some work) and some parts of the common runtime implemented in C. It will use a hand-written parser, and LLVM for its back-end.

At the same time, I am trying out some approaches to concurrency paradigms in my Parallel::RCVM::* perl modules (not in CPAN yet, but eventually). Getting real-world work done in a concurrency framework similar to ZACL's has been very educational, and continues to influence ZACL's direction.

Copyright (C) Bill Moyer / TTK Ciar, 2020