Suggest Completion

script

function scanBackwardToWhitespace(str, startIndex) {
	let i = startIndex;
	while (i > 0 && !/\s/.test(str[i - 1])) {
		i--
	}
	return i
}

function findMatchingWords(str, substring) {
	const lowerSub = substring.toLowerCase()
	let arr = str
		.split(/\s+/) // split on whitespace
		.map(x => x.replace(/^[\p{P}\p{S}]+|[\p{P}\p{S}]+$/gu, ''))
		.filter(word => word.toLowerCase().startsWith(lowerSub))
	return [...new Set(arr)]
}

let f = () => {
	// get values
	const text = editor.getText()
	const [st, len] = editor.getSelectedRange()
	var newSt = st
	let query = editor.getSelectedText()
	if (query.length == 0) {
		newSt = scanBackwardToWhitespace(text, st)
		query = text.substring(newSt, st)
	}
	if (query.length == 0) { return false}

	// look for matching words 
	let matches = findMatchingWords(text, query)
	if (matches.length == 0) { return false }

	// prompt to select a word
	let p = new Prompt()
	p.title = "Complete"
	p.isCancellable = true
	for (let m of matches) {
		if (m != query) {
			p.addButton(m, m)
		}
	}
	if (!p.show()) { return false }

	let sel = p.buttonPressed
	editor.setTextInRange(newSt, query.length, sel)
	editor.setSelectedRange(newSt + sel.length, 0)
	editor.activate()
	return true
}

if (!f()) {
	context.cancel()
}