AlBasmala RSS About

Posts   tagged   “python”

Here are some of my latest thoughts on python… such as thread-first and loop (•̀ᴗ•́)و

💐 Repl Driven Development: /Editor Integrated REPLs for all languages/ 🔁

Article image

The MELPA package makes the philosophy of REPL Driven Development (RDD) accessible to any language that has a primitive CLI repl: The result is an Emacs interface for the language, where code of your choosing is evaluated, and results are echoed at your cursor in overlays.

That is, with Repl aided development, you make software by starting with an already working program (i.e., the repl) then incrementlly “teach it” to be the program you want, by defining & redefining things. Until satisfied, loop: Type/modify code in your editor, press some keys to evaluate what you wrote/modified in the currently running system, and explore/test the resulting runtime.

RDD is programming emphasising fast & rich feedback from a running system. RDD is fantastic for quickly teaching/exploring an idea; as such, the running example of this article will be on servers —no prior experience with servers is assumed. The main examples will be in JavaScript, Python, and Java. (Since JavaScript is just Lisp in C clothing, we will not discuss Lisp.) Since Java is verbose, the power of REPLs really pays off when exploring a new idea. We see how many imports and setup-code simply disappear in the RDD approach, letting you focus on the core idea you're exploring/teaching. For comparison, a traditional self-contained Java server program is ~30 lines long whereas the focused RDD approach is ~4 lines long.

tdlr: This library provides the Emacs built-in C-x C-e behaviour for arbitrary languages, provided they have a primitive cli REPL.

💐 Making VSCode itself a Java REPL 🔁

Article image

VSCode evaluates Java code wherever it sees it, by sending it to a JShell in the background, and echos the results in a friendly way!

This is achieved with a meta-extension for VSCode that makes VSCode into a living, breathing, JS interpreter: It can execute arbitrary JS that alters VSCode on-the-fly. (Inspired by using Emacs and Lisp!)

The relevant docs show how to make a similar REPL for Python, Ruby, Clojure, Common Lisp, JavaScript, Typescript, Haskell, and of-course Java.

Thanks for reading everything! 😁 Bye! 👋

Creative Commons License
Life & Computing Science by Musa Al-hassy is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License