Clickable usernames and hashtags

Should work well enough. Report edge cases.

src/lib/utils/structuretext.js

@@ -0,0 +1,53 @@
+const constants = require("../constants")
+const {Parser} = require("./parser/parser")
+
+function tryMatch(text, against, callback) {
+	let matched = text.match(against)
+	if (matched) callback(matched)
+}
+
+function textToParts(text) {
+	return [{type: "text", text: text}]
+}
+
+function replacePart(parts, index, match, replacements) {
+	const toReplace = parts.splice(index, 1)[0]
+	const before = toReplace.text.slice(0, match.index)
+	const after = toReplace.text.slice(match.index + match[0].length)
+	parts.splice(index, 0, ...textToParts(before), ...replacements, ...textToParts(after))
+}
+
+function partsUsername(parts) {
+	for (let i = 0; i < parts.length; i++) {
+		if (parts[i].type === "text") {
+			tryMatch(parts[i].text, `@(${constants.external.username_regex})`, match => {
+				replacePart(parts, i, match, [
+					{type: "user", text: match[0], user: match[1]}
+				])
+				i += 1 // skip parts: user
+			})
+		}
+	}
+}
+
+function partsHashtag(parts) {
+	for (let i = 0; i < parts.length; i++) {
+		if (parts[i].type === "text") {
+			tryMatch(parts[i].text, `#(${constants.external.hashtag_regex})`, match => {
+				replacePart(parts, i, match, [
+					{type: "hashtag", text: match[0], hashtag: match[1]}
+				])
+				i += 1 // skip parts: hashtag
+			})
+		}
+	}
+}
+
+function structure(text) {
+	const parts = textToParts(text)
+	partsUsername(parts)
+	partsHashtag(parts)
+	return parts
+}
+
+module.exports.structure = structure