Example code to convert the body of a single Mastodon post to Markdown (see https://mastodon.thi.ng/@toxi/115496400071927410 for details)

mastodon-markdown.ts

import { parseHtml } from "@thi.ng/hiccup-html-parse";
import { serialize } from "@thi.ng/hiccup-markdown";
import { arrayZipper, type Location } from "@thi.ng/zipper";

const HOST = "mastodon.thi.ng";
const STATUS_ID = "115464108396925195";

// load a Mastodon status via API
const res = await (
	await fetch(`https://${HOST}/api/v1/statuses/${STATUS_ID}`)
).json();

// parse HTML content into thing/hiccup format (nested JS arrays)
const parsed = parseHtml(res.content, { whitespace: true }).result!;

// structure of parsed example:
// [["p", {}, "text"], ["p", {}, ...], ...]

// recursively traverse result document/array using thi.ng/zipper
// and replace all <span> elements with their raw text body

let loc: Location<any> | undefined = arrayZipper(parsed);
do {
	// move to logically next item (depth-first)
	loc = loc.next;
	// check if current loc is a span element and if so transform it
	if (Array.isArray(loc?.node) && loc?.node[0] == "span") {
		loc = loc.replace(loc.node[2]);
	}
	// (insert other transforms...)
	// ...
} while (loc?.next);

// serialize hiccup to markdown
console.log(serialize(loc?.root));

/*
Example result (in markdown format):

This week I've been rewriting (in Zig) the position-based dynamics &
cellular-automata engines used for the cloth sim in my
[#DANZA](https://mastodon.thi.ng/tags/DANZA) art project (check the hashtag for
older WIP)... Still endless tweaking, but could already stare at this beauty for
hours, literally!

(And of course, I'm also again "dogfooding"
[http://thi.ng/genart-api](http://thi.ng/genart-api) for defining/handling
parameters and animation timing...)

[#GenerativeArt](https://mastodon.thi.ng/tags/GenerativeArt)
[#AlgorithmicArt](https://mastodon.thi.ng/tags/AlgorithmicArt)
[#CellularAutomata](https://mastodon.thi.ng/tags/CellularAutomata)
[#Physics](https://mastodon.thi.ng/tags/Physics)
[#Simulation](https://mastodon.thi.ng/tags/Simulation)
[#GenArtAPI](https://mastodon.thi.ng/tags/GenArtAPI)
[#Zig](https://mastodon.thi.ng/tags/Zig)
[#WASM](https://mastodon.thi.ng/tags/WASM)
[#WebAssembly](https://mastodon.thi.ng/tags/WebAssembly)
[#NoAI](https://mastodon.thi.ng/tags/NoAI)
*/