GUID Golf

A mini adventure in minified code

in Software — 198 words — 1 min read — No comments yet

A few months back I was digging through the minified source of a webpage, and I came across an interesting way to create a GUID:1

var b = (a) => a?(a^Math.random()*16>>a/4).toString(16):([1e7]+-1e3+-4e3+-8e3+-1e11).replace(/[018]/g,b)

I was really surprised at how it was minified—seemed like a really clever minifier if it was able to rewrite a simple callback function into a recursion and a ternary operator just to shave off a few characters.

I figured the part with the numbers added together was probably not that different than the unminified version, and was able to find something similar in this article about GUID generation, which contains a code comment mentioning this Stack Overflow answer. The question for that answer has another answer with the code I was looking for, and that answer cited this GitHub Gist. It had to laugh when I saw that it wasn’t minified—it was golfed. “Clever minifier” indeed—a clever human minifier.

Footnotes

  1. I recognize that this isn’t a “proper” GUID because it relies on Math.random(). As Stack Overflow user broofa puts it, “solutions based on Math.random() do not provide good uniqueness guarantees.” But the website in question didn’t need very good uniqueness guarantees for what it was doing. ↩

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