Over 10 years ago, I had this sort of a prediction that, with the massive adoption of a dynamic language like javascript on both client/server sides and test-driven development gaining a lot of ground, the future of programming would be dynamic and “feedback-driven”. As in, you would immediately see the results of your code as you type, based on the tests you created. To naively simplify, imagine a split screen of your code editor and a console view showing relevant watch expressions from the code you’re typing.
Instead what happened was the industry’s focus shifted to type safety and smart compilers, and I followed along. I’m just not smart enough to question where the whole industry was heading. And my speck of imagination on how coding would have looked like in the future wasn’t completely thought out. It was just that, a speck of imagination that occurred to me as I was debugging something tedious.
Now, most of the programming language world, seem to be focusing on smarter compilers. But is there some language or platform, that focus instead on a different kind of programming paradigm (not sort of OOP, FP paradigm, may be call it the programming workflow paradigm?). May be it comes with a really strong debugger tooling that’s constantly giving you feedback on what your code is actually doing. Think REPL on steroids. I can imagine there would be challenges with parsing/evaluating incomplete code syntax and functions. So I guess, the whole compiler/translator side has to be thought out from the ground up as well.
Disclaimer: There’s a good chance I simply don’t know what I’m talking about because I’m no language designer or even close to understanding how programming languages and it’s ecosystems are created. Just sharing some thoughts I had as a junior dev back in the day.
IMO Clojure really shines with a REPL-driven development, where you have a REPL to interact with a live running application. You can have a very productive workflow where you conduct little code experiments and incrementally build up functionality. Typically, in this workflow, you’re also sending code (as S-expression forms) to the REPL from your editor to inspect or test the output (some tools have inline display of the output like the Calva Clojure extension for VS Code ). Any tests you come up with in the REPL can usually be turned into unit tests fairly easily (e.g. copy/paste into a tests file) and those tests can be run automatically on source change in the background as well or from the REPL itself. There are also tools on built on top of the REPL that can be used for live inspection of data structures, data visualization/exploration, creating watches on variables, etc. Although the Clojure REPL is best used when developing Clojure applications, I’ve also found it useful for getting familiar with Java apps such as a complex Spring Framework web app that I had to work on.
For Python, I typically use Jupyter/IPython to hash out and test the functionality I need and I find provides a much superior experience to just using the regular
$ pythonREPL. With PyCharm, the Jupyter integration is really nice and makes the experience a lot more liquid than having to flip between a browser tab and your editor. It’s not quite as nice as a REPL integrated with your live running app, but I personally find it more productive than running a debugger or just spamming print statements and modifying and rerunning my Python script 100X.I really hope that more languages start to better support for more exploratory, experimental development workflows since sometimes I just want to play around to get familiar with using a library or tool in a sandbox. I think there’s a lot of room to improve developer productivity through blending and integrating together REPLs, notebook-like environments, hot code reloading and other tools/techniques to enable rapid prototyping and faster feedback for developers. Tests and type checking are very useful when you’ve figured out what you need and need to have sanity checks, but can be a major hindrance in that “figuring it out” exploratory stage.
The REPL experience in Clojure is powerful. Calva includes a functional debugger as well and I have to say it all leads to a frictionless experience.
It’s the same with elixir and it’s interactive REPL! I really love working with it.