@leeoniya/ufuzzy/dist/uFuzzy.iife.js

A tiny, efficient fuzzy matcher that doesn't suck

/**
* Copyright (c) 2025, Leon Sorokin
* All rights reserved. (MIT Licensed)
*
* uFuzzy.js (μFuzzy)
* A tiny, efficient fuzzy matcher that doesn't suck
* https://github.com/leeoniya/uFuzzy (v1.0.18)
*/

var uFuzzy = (function () {
	'use strict';

	const cmp = (a, b) => a > b ? 1 : a < b ? -1 : 0;

	const inf = Infinity;

	// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_expressions#escaping
	const escapeRegExp = str => str.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");

	// meh, magic tmp placeholder, must be tolerant to toLocaleLowerCase(), interSplit, and intraSplit
	const EXACT_HERE = 'eexxaacctt';

	const PUNCT_RE = /\p{P}/gu;

	const LATIN_UPPER = 'A-Z';
	const LATIN_LOWER = 'a-z';

	const COLLATE_ARGS = ['en', { numeric: true, sensitivity: 'base' }];

	const swapAlpha = (str, upper, lower) => str.replace(LATIN_UPPER, upper).replace(LATIN_LOWER, lower);

	const OPTS = {
		// whether regexps use a /u unicode flag
		unicode: false,

		alpha: null,

		// term segmentation & punct/whitespace merging
		interSplit: "[^A-Za-z\\d']+",
		intraSplit: "[a-z][A-Z]",

		// inter bounds that will be used to increase lft2/rgt2 info counters
		interBound: "[^A-Za-z\\d]",
		// intra bounds that will be used to increase lft1/rgt1 info counters
		intraBound: "[A-Za-z]\\d|\\d[A-Za-z]|[a-z][A-Z]",

		// inter-bounds mode
		// 2 = strict (will only match 'man' on whitepace and punct boundaries: Mega Man, Mega_Man, mega.man)
		// 1 = loose  (plus allowance for alpha-num and case-change boundaries: MegaMan, 0007man)
		// 0 = any    (will match 'man' as any substring: megamaniac)
		interLft: 0,
		interRgt: 0,

		// allowance between terms
		interChars: '.',
		interIns: inf,

		// allowance between chars in terms
		intraChars: "[a-z\\d']", // internally case-insensitive
		intraIns: null,

		intraContr: "'[a-z]{1,2}\\b",

		// multi-insert or single-error mode
		intraMode: 0,

		// single-error bounds for errors within terms, default requires exact first char
		intraSlice: [1, inf],

		// single-error tolerance toggles
		intraSub: null,
		intraTrn: null,
		intraDel: null,

		// can post-filter matches that are too far apart in distance or length
		// (since intraIns is between each char, it can accum to nonsense matches)
		intraFilt: (term, match, index) => true, // should this also accept WIP info?

		toUpper: str => str.toLocaleUpperCase(),
		toLower: str => str.toLocaleLowerCase(),
		compare: null,

		// final sorting fn
		sort: (info, haystack, needle, compare = cmp) => {
			let {
				idx,
				chars,
				terms,
				interLft2,
				interLft1,
			//	interRgt2,
			//	interRgt1,
				start,
				intraIns,
				interIns,
				cases,
			} = info;

			return idx.map((v, i) => i).sort((ia, ib) => (
				// most contig chars matched
				chars[ib] - chars[ia] ||
				// least char intra-fuzz (most contiguous)
				intraIns[ia] - intraIns[ib] ||
				// most prefix bounds, boosted by full term matches
				(
					(terms[ib] + interLft2[ib] + 0.5 * interLft1[ib]) -
					(terms[ia] + interLft2[ia] + 0.5 * interLft1[ia])
				) ||
				// highest density of match (least span)
			//	span[ia] - span[ib] ||
				// highest density of match (least term inter-fuzz)
				interIns[ia] - interIns[ib] ||
				// earliest start of match
				start[ia] - start[ib] ||
				// case match
				cases[ib] - cases[ia] ||
				// alphabetic
				compare(haystack[idx[ia]], haystack[idx[ib]])
			));
		},
	};

	const lazyRepeat = (chars, limit) => (
		limit == 0   ? ''           :
		limit == 1   ? chars + '??' :
		limit == inf ? chars + '*?' :
		               chars + `{0,${limit}}?`
	);

	const mode2Tpl = '(?:\\b|_)';

	function uFuzzy(opts) {
		opts = Object.assign({}, OPTS, opts);

		let {
			unicode,
			interLft,
			interRgt,
			intraMode,
			intraSlice,
			intraIns,
			intraSub,
			intraTrn,
			intraDel,
			intraContr,
			intraSplit: _intraSplit,
			interSplit: _interSplit,
			intraBound: _intraBound,
			interBound: _interBound,
			intraChars,
			toUpper,
			toLower,
			compare,
		} = opts;

		intraIns ??= intraMode;
		intraSub ??= intraMode;
		intraTrn ??= intraMode;
		intraDel ??= intraMode;

		compare ??= typeof Intl == "undefined" ? cmp : new Intl.Collator(...COLLATE_ARGS).compare;

		let alpha = opts.letters ?? opts.alpha;

		if (alpha != null) {
			let upper = toUpper(alpha);
			let lower = toLower(alpha);

			_interSplit = swapAlpha(_interSplit, upper, lower);
			_intraSplit = swapAlpha(_intraSplit, upper, lower);
			_interBound = swapAlpha(_interBound, upper, lower);
			_intraBound = swapAlpha(_intraBound, upper, lower);
			intraChars = swapAlpha(intraChars, upper, lower);
			intraContr = swapAlpha(intraContr, upper, lower);
		}

		let uFlag = unicode ? 'u' : '';

		const quotedAny = '".+?"';
		const EXACTS_RE = new RegExp(quotedAny, 'gi' + uFlag);
		const NEGS_RE = new RegExp(`(?:\\s+|^)-(?:${intraChars}+|${quotedAny})`, 'gi' + uFlag);

		let { intraRules } = opts;

		if (intraRules == null) {
			intraRules = p => {
				// default is exact term matches only
				let _intraSlice = OPTS.intraSlice, // requires first char
					_intraIns = 0,
					_intraSub = 0,
					_intraTrn = 0,
					_intraDel = 0;

				// only-digits strings should match exactly, else special rules for short strings
				if (/[^\d]/.test(p)) {
					let plen = p.length;

					// prevent junk matches by requiring stricter rules for short terms
					if (plen <= 4) {
						if (plen >= 3) {
							// one swap in non-first char when 3-4 chars
							_intraTrn = Math.min(intraTrn, 1);

							// or one insertion when 4 chars
							if (plen == 4)
								_intraIns = Math.min(intraIns, 1);
						}
						// else exact match when 1-2 chars
					}
					// use supplied opts
					else {
						_intraSlice = intraSlice;
						_intraIns = intraIns,
						_intraSub = intraSub,
						_intraTrn = intraTrn,
						_intraDel = intraDel;
					}
				}

				return {
					intraSlice: _intraSlice,
					intraIns: _intraIns,
					intraSub: _intraSub,
					intraTrn: _intraTrn,
					intraDel: _intraDel,
				};
			};
		}

		let withIntraSplit = !!_intraSplit;

		let intraSplit = new RegExp(_intraSplit, 'g' + uFlag);
		let interSplit = new RegExp(_interSplit, 'g' + uFlag);

		let trimRe = new RegExp('^' + _interSplit + '|' + _interSplit + '$', 'g' + uFlag);
		let contrsRe = new RegExp(intraContr, 'gi' + uFlag);

		const split = (needle, keepCase = false) => {
			let exacts = [];

			needle = needle.replace(EXACTS_RE, m => {
				exacts.push(m);
				return EXACT_HERE;
			});

			needle = needle.replace(trimRe, '');

			if (!keepCase)
				needle = toLower(needle);

			if (withIntraSplit)
				needle = needle.replace(intraSplit, m => m[0] + ' ' + m[1]);

			let j = 0;
			return needle.split(interSplit).filter(t => t != '').map(v => v === EXACT_HERE ? exacts[j++] : v);
		};

		const NUM_OR_ALPHA_RE = /[^\d]+|\d+/g;

		const prepQuery = (needle, capt = 0, interOR = false) => {
			// split on punct, whitespace, num-alpha, and upper-lower boundaries
			let parts = split(needle);

			if (parts.length == 0)
				return [];

			// split out any detected contractions for each term that become required suffixes
			let contrs = Array(parts.length).fill('');
			parts = parts.map((p, pi) => p.replace(contrsRe, m => {
				contrs[pi] = m;
				return '';
			}));

			// array of regexp tpls for each term
			let reTpl;

			// allows single mutations within each term
			if (intraMode == 1) {
				reTpl = parts.map((p, pi) => {
					if (p[0] === '"')
						return escapeRegExp(p.slice(1, -1));

					let reTpl = '';

					// split into numeric and alpha parts, so numbers are only matched as following punct or alpha boundaries, without swaps or insertions
					for (let m of p.matchAll(NUM_OR_ALPHA_RE)) {
						let p = m[0];

						let {
							intraSlice,
							intraIns,
							intraSub,
							intraTrn,
							intraDel,
						} = intraRules(p);

						if (intraIns + intraSub + intraTrn + intraDel == 0)
							reTpl += p + contrs[pi];
						else {
							let [lftIdx, rgtIdx] = intraSlice;
							let lftChar = p.slice(0, lftIdx); // prefix
							let rgtChar = p.slice(rgtIdx);    // suffix

							let chars = p.slice(lftIdx, rgtIdx);

							// neg lookahead to prefer matching 'Test' instead of 'tTest' in ManifestTest or fittest
							// but skip when search term contains leading repetition (aardvark, aaa)
							if (intraIns == 1 && lftChar.length == 1 && lftChar != chars[0])
								lftChar += '(?!' + lftChar + ')';

							let numChars = chars.length;

							let variants = [p];

							// variants with single char substitutions
							if (intraSub) {
								for (let i = 0; i < numChars; i++)
									variants.push(lftChar + chars.slice(0, i) + intraChars + chars.slice(i + 1) + rgtChar);
							}

							// variants with single transpositions
							if (intraTrn) {
								for (let i = 0; i < numChars - 1; i++) {
									if (chars[i] != chars[i+1])
										variants.push(lftChar + chars.slice(0, i) + chars[i+1] + chars[i] + chars.slice(i + 2) + rgtChar);
								}
							}

							// variants with single char omissions
							if (intraDel) {
								for (let i = 0; i < numChars; i++)
									variants.push(lftChar + chars.slice(0, i + 1) + '?' + chars.slice(i + 1) + rgtChar);
							}

							// variants with single char insertions
							if (intraIns) {
								let intraInsTpl = lazyRepeat(intraChars, 1);

								for (let i = 0; i < numChars; i++)
									variants.push(lftChar + chars.slice(0, i) + intraInsTpl + chars.slice(i) + rgtChar);
							}

							reTpl += '(?:' + variants.join('|') + ')' + contrs[pi];
						}
					}

				//	console.log(reTpl);

					return reTpl;
				});
			}
			else {
				let intraInsTpl = lazyRepeat(intraChars, intraIns);

				// capture at char level
				if (capt == 2 && intraIns > 0) {
					// sadly, we also have to capture the inter-term junk via parenth-wrapping .*?
					// to accum other capture groups' indices for \b boosting during scoring
					intraInsTpl = ')(' + intraInsTpl + ')(';
				}

				reTpl = parts.map((p, pi) => p[0] === '"' ? escapeRegExp(p.slice(1, -1)) :  p.split('').map((c, i, chars) => {
					// neg lookahead to prefer matching 'Test' instead of 'tTest' in ManifestTest or fittest
					// but skip when search term contains leading repetition (aardvark, aaa)
					if (intraIns == 1 && i == 0 && chars.length > 1 && c != chars[i+1])
						c += '(?!' + c + ')';

					return c;
				}).join(intraInsTpl) + contrs[pi]);
			}

		//	console.log(reTpl);

			// this only helps to reduce initial matches early when they can be detected
			// TODO: might want a mode 3 that excludes _
			let preTpl = interLft == 2 ? mode2Tpl : '';
			let sufTpl = interRgt == 2 ? mode2Tpl : '';

			let interCharsTpl = sufTpl + lazyRepeat(opts.interChars, opts.interIns) + preTpl;

			// capture at word level
			if (capt > 0) {
				if (interOR) {
					// this is basically for doing .matchAll() occurence counting and highlighting without needing permuted ooo needles
					reTpl = preTpl + '(' + reTpl.join(')' + sufTpl + '|' + preTpl + '(') + ')' + sufTpl;
				}
				else {
					// sadly, we also have to capture the inter-term junk via parenth-wrapping .*?
					// to accum other capture groups' indices for \b boosting during scoring
					reTpl = '(' + reTpl.join(')(' + interCharsTpl + ')(') + ')';
					reTpl = '(.??' + preTpl + ')' + reTpl + '(' + sufTpl + '.*)'; // nit: trailing capture here assumes interIns = Inf
				}
			}
			else {
				reTpl = reTpl.join(interCharsTpl);
				reTpl = preTpl + reTpl + sufTpl;
			}

		//	console.log(reTpl);

			return [new RegExp(reTpl, 'i' + uFlag), parts, contrs];
		};

		const filter = (haystack, needle, idxs) => {

			let [query] = prepQuery(needle);

			if (query == null)
				return null;

			let out = [];

			if (idxs != null) {
				for (let i = 0; i < idxs.length; i++) {
					let idx = idxs[i];
					query.test(haystack[idx]) && out.push(idx);
				}
			}
			else {
				for (let i = 0; i < haystack.length; i++)
					query.test(haystack[i]) && out.push(i);
			}

			return out;
		};

		let withIntraBound = !!_intraBound;

		let interBound = new RegExp(_interBound, uFlag);
		let intraBound = new RegExp(_intraBound, uFlag);

		const info = (idxs, haystack, needle) => {

			let [query, parts, contrs] = prepQuery(needle, 1);
			let partsCased = split(needle, true);
			let [queryR] = prepQuery(needle, 2);
			let partsLen = parts.length;

			let _terms      = Array(partsLen);
			let _termsCased = Array(partsLen);

			for (let j = 0; j < partsLen; j++) {
				let part      = parts[j];
				let partCased = partsCased[j];

				let term      = part[0]      == '"' ? part.slice(1, -1)      : part      + contrs[j];
				let termCased = partCased[0] == '"' ? partCased.slice(1, -1) : partCased + contrs[j];

				_terms[j]      = term;
				_termsCased[j] = termCased;
			}

			let len = idxs.length;

			let field = Array(len).fill(0);

			let info = {
				// idx in haystack
				idx: Array(len),

				// start of match
				start: field.slice(),
				// length of match
			//	span: field.slice(),

				// contiguous chars matched
				chars: field.slice(),

				// case matched in term (via term.includes(match))
				cases: field.slice(),

				// contiguous (no fuzz) and bounded terms (intra=0, lft2/1, rgt2/1)
				// excludes terms that are contiguous but have < 2 bounds (substrings)
				terms: field.slice(),

				// cumulative length of unmatched chars (fuzz) within span
				interIns: field.slice(), // between terms
				intraIns: field.slice(), // within terms

				// interLft/interRgt counters
				interLft2: field.slice(),
				interRgt2: field.slice(),
				interLft1: field.slice(),
				interRgt1: field.slice(),

				ranges: Array(len),
			};

			// might discard idxs based on bounds checks
			let mayDiscard = interLft == 1 || interRgt == 1;

			let ii = 0;

			for (let i = 0; i < idxs.length; i++) {
				let mhstr = haystack[idxs[i]];

				// the matched parts are [full, junk, term, junk, term, junk]
				let m = mhstr.match(query);

				// leading junk
				let start = m.index + m[1].length;

				let idxAcc = start;
			//	let span = m[0].length;

				let disc = false;
				let lft2 = 0;
				let lft1 = 0;
				let rgt2 = 0;
				let rgt1 = 0;
				let chars = 0;
				let terms = 0;
				let cases = 0;
				let inter = 0;
				let intra = 0;

				let refine = [];

				for (let j = 0, k = 2; j < partsLen; j++, k+=2) {
					let group     = toLower(m[k]);
					let term      = _terms[j];
					let termCased = _termsCased[j];
					let termLen   = term.length;
					let groupLen  = group.length;
					let fullMatch = group == term;

					if (m[k] == termCased)
						cases++;

					// this won't handle the case when an exact match exists across the boundary of the current group and the next junk
					// e.g. blob,ob when searching for 'bob' but finding the earlier `blob` (with extra insertion)
					if (!fullMatch && m[k+1].length >= termLen) {
						// probe for exact match in inter junk (TODO: maybe even in this matched part?)
						let idxOf = toLower(m[k+1]).indexOf(term);

						if (idxOf > -1) {
							refine.push(idxAcc, groupLen, idxOf, termLen);
							idxAcc += refineMatch(m, k, idxOf, termLen);
							group = term;
							groupLen = termLen;
							fullMatch = true;

							if (j == 0)
								start = idxAcc;
						}
					}

					if (mayDiscard || fullMatch) {
						// does group's left and/or right land on \b
						let lftCharIdx = idxAcc - 1;
						let rgtCharIdx = idxAcc + groupLen;

						let isPre = false;
						let isSuf = false;

						// prefix info
						if (lftCharIdx == -1           || interBound.test(mhstr[lftCharIdx])) {
							fullMatch && lft2++;
							isPre = true;
						}
						else {
							if (interLft == 2) {
								disc = true;
								break;
							}

							if (withIntraBound && intraBound.test(mhstr[lftCharIdx] + mhstr[lftCharIdx + 1])) {
								fullMatch && lft1++;
								isPre = true;
							}
							else {
								if (interLft == 1) {
									// regexps are eager, so try to improve the match by probing forward inter junk for exact match at a boundary
									let junk = m[k+1];
									let junkIdx = idxAcc + groupLen;

									if (junk.length >= termLen) {
										let idxOf = 0;
										let found = false;
										let re = new RegExp(term, 'ig' + uFlag);

										let m2;
										while (m2 = re.exec(junk)) {
											idxOf = m2.index;

											let charIdx = junkIdx + idxOf;
											let lftCharIdx = charIdx - 1;

											if (lftCharIdx == -1 || interBound.test(mhstr[lftCharIdx])) {
												lft2++;
												found = true;
												break;
											}
											else if (intraBound.test(mhstr[lftCharIdx] + mhstr[charIdx])) {
												lft1++;
												found = true;
												break;
											}
										}

										if (found) {
											isPre = true;

											// identical to exact term refinement pass above
											refine.push(idxAcc, groupLen, idxOf, termLen);
											idxAcc += refineMatch(m, k, idxOf, termLen);
											group = term;
											groupLen = termLen;
											fullMatch = true;

											if (j == 0)
												start = idxAcc;
										}
									}

									if (!isPre) {
										disc = true;
										break;
									}
								}
							}
						}

						// suffix info
						if (rgtCharIdx == mhstr.length || interBound.test(mhstr[rgtCharIdx])) {
							fullMatch && rgt2++;
							isSuf = true;
						}
						else {
							if (interRgt == 2) {
								disc = true;
								break;
							}

							if (withIntraBound && intraBound.test(mhstr[rgtCharIdx - 1] + mhstr[rgtCharIdx])) {
								fullMatch && rgt1++;
								isSuf = true;
							}
							else {
								if (interRgt == 1) {
									disc = true;
									break;
								}
							}
						}

						if (fullMatch) {
							chars += termLen;

							if (isPre && isSuf)
								terms++;
						}
					}

					if (groupLen > termLen)
						intra += groupLen - termLen; // intraFuzz

					if (j > 0)
						inter += m[k-1].length; // interFuzz

					// TODO: group here is lowercased, which is okay for length cmp, but not more case-sensitive filts
					if (!opts.intraFilt(term, group, idxAcc)) {
						disc = true;
						break;
					}

					if (j < partsLen - 1)
						idxAcc += groupLen + m[k+1].length;
				}

				if (!disc) {
					info.idx[ii]       = idxs[i];
					info.interLft2[ii] = lft2;
					info.interLft1[ii] = lft1;
					info.interRgt2[ii] = rgt2;
					info.interRgt1[ii] = rgt1;
					info.chars[ii]     = chars;
					info.terms[ii]     = terms;
					info.cases[ii]     = cases;
					info.interIns[ii]  = inter;
					info.intraIns[ii]  = intra;

					info.start[ii] = start;
				//	info.span[ii] = span;

					// ranges
					let m = mhstr.match(queryR);

					let idxAcc = m.index + m[1].length;

					let refLen = refine.length;
					let ri = refLen > 0 ? 0 : Infinity;
					let lastRi = refLen - 4;

					for (let i = 2; i < m.length;) {
						let len = m[i].length;

						if (ri <= lastRi && refine[ri] == idxAcc) {
							let groupLen = refine[ri+1];
							let idxOf    = refine[ri+2];
							let termLen  = refine[ri+3];

							// advance to end of original (full) group match that includes intra-junk
							let j = i;
							let v = '';
							for (let _len = 0; _len < groupLen; j++) {
								v += m[j];
								_len += m[j].length;
							}

							m.splice(i, j - i, v);

							idxAcc += refineMatch(m, i, idxOf, termLen);

							ri += 4;
						}
						else {
							idxAcc += len;
							i++;
						}
					}

					idxAcc = m.index + m[1].length;

					let ranges = info.ranges[ii] = [];
					let from = idxAcc;
					let to = idxAcc;

					for (let i = 2; i < m.length; i++) {
						let len = m[i].length;

						idxAcc += len;

						if (i % 2 == 0)
							to = idxAcc;
						else if (len > 0) {
							ranges.push(from, to);
							from = to = idxAcc;
						}
					}

					if (to > from)
						ranges.push(from, to);

					ii++;
				}
			}

			// trim arrays
			if (ii < idxs.length) {
				for (let k in info)
					info[k] = info[k].slice(0, ii);
			}

			return info;
		};

		const refineMatch = (m, k, idxInNext, termLen) => {
			// shift the current group into the prior junk
			let prepend = m[k] + m[k+1].slice(0, idxInNext);
			m[k-1] += prepend;
			m[k]    = m[k+1].slice(idxInNext, idxInNext + termLen);
			m[k+1]  = m[k+1].slice(idxInNext + termLen);
			return prepend.length;
		};

		const OOO_TERMS_LIMIT = 5;

		// returns [idxs, info, order]
		const _search = (haystack, needle, outOfOrder, infoThresh = 1e3, preFiltered) => {
			outOfOrder = !outOfOrder ? 0 : outOfOrder === true ? OOO_TERMS_LIMIT : outOfOrder;

			let needles = null;
			let matches = null;

			let negs = [];

			needle = needle.replace(NEGS_RE, m => {
				let neg = m.trim().slice(1);

				neg = neg[0] === '"' ? escapeRegExp(neg.slice(1,-1)) :  neg.replace(PUNCT_RE, '');

				if (neg != '')
					negs.push(neg);

				return '';
			});

			let terms = split(needle);

			let negsRe;

			if (negs.length > 0) {
				negsRe = new RegExp(negs.join('|'), 'i' + uFlag);

				if (terms.length == 0) {
					let idxs = [];

					for (let i = 0; i < haystack.length; i++) {
						if (!negsRe.test(haystack[i]))
							idxs.push(i);
					}

					return [idxs, null, null];
				}
			}
			else {
				// abort search (needle is empty after pre-processing, e.g. no alpha-numeric chars)
				if (terms.length == 0)
					return [null, null, null];
			}

		//	console.log(negs);
		//	console.log(needle);

			if (outOfOrder > 0) {
				// since uFuzzy is an AND-based search, we can iteratively pre-reduce the haystack by searching
				// for each term in isolation before running permutations on what's left.
				// this is a major perf win. e.g. searching "test man ger pp a" goes from 570ms -> 14ms
				let terms = split(needle);

				if (terms.length > 1) {
					// longest -> shortest
					let terms2 = terms.slice().sort((a, b) => b.length - a.length);

					for (let ti = 0; ti < terms2.length; ti++) {
						// no haystack item contained all terms
						if (preFiltered?.length == 0)
							return [[], null, null];

						preFiltered = filter(haystack, terms2[ti], preFiltered);
					}

					// avoid combinatorial explosion by limiting outOfOrder to 5 terms (120 max searches)
					// fall back to just filter() otherwise
					if (terms.length > outOfOrder)
						return [preFiltered, null, null];

					needles = permute(terms).map(perm => perm.join(' '));

					// filtered matches for each needle excluding same matches for prior needles
					matches = [];

					// keeps track of already-matched idxs to skip in follow-up permutations
					let matchedIdxs = new Set();

					for (let ni = 0; ni < needles.length; ni++) {
						if (matchedIdxs.size < preFiltered.length) {
							// filter further for this needle, exclude already-matched
							let preFiltered2 = preFiltered.filter(idx => !matchedIdxs.has(idx));

							let matched = filter(haystack, needles[ni], preFiltered2);

							for (let j = 0; j < matched.length; j++)
								matchedIdxs.add(matched[j]);

							matches.push(matched);
						}
						else
							matches.push([]);
					}
				}
			}

			// interOR
		//	console.log(prepQuery(needle, 1, null, true));

			// non-ooo or ooo w/single term
			if (needles == null) {
				needles = [needle];
				matches = [preFiltered?.length > 0 ? preFiltered : filter(haystack, needle)];
			}

			let retInfo = null;
			let retOrder = null;

			if (negs.length > 0)
				matches = matches.map(idxs => idxs.filter(idx => !negsRe.test(haystack[idx])));

			let matchCount = matches.reduce((acc, idxs) => acc + idxs.length, 0);

			// rank, sort, concat
			if (matchCount <= infoThresh) {
				retInfo = {};
				retOrder = [];

				for (let ni = 0; ni < matches.length; ni++) {
					let idxs = matches[ni];

					if (idxs == null || idxs.length == 0)
						continue;

					let needle = needles[ni];
					let _info = info(idxs, haystack, needle);
					let order = opts.sort(_info, haystack, needle, compare);

					// offset idxs for concat'ing infos
					if (ni > 0) {
						for (let i = 0; i < order.length; i++)
							order[i] += retOrder.length;
					}

					for (let k in _info)
						retInfo[k] = (retInfo[k] ?? []).concat(_info[k]);

					retOrder = retOrder.concat(order);
				}
			}

			return [
				[].concat(...matches),
				retInfo,
				retOrder,
			];
		};

		return {
			search: (...args) => {
				let out = _search(...args);
				return out;
			},
			split,
			filter,
			info,
			sort: opts.sort,
		};
	}

	const latinize = (() => {
		let accents = {
			A: 'ÁÀÃÂÄĄ',
			a: 'áàãâäą',
			E: 'ÉÈÊËĖ',
			e: 'éèêëę',
			I: 'ÍÌÎÏĮ',
			i: 'íìîïį',
			O: 'ÓÒÔÕÖ',
			o: 'óòôõö',
			U: 'ÚÙÛÜŪŲ',
			u: 'úùûüūų',
			C: 'ÇČĆ',
			c: 'çčć',
			L: 'Ł',
			l: 'ł',
			N: 'ÑŃ',
			n: 'ñń',
			S: 'ŠŚ',
			s: 'šś',
			Z: 'ŻŹ',
			z: 'żź'
		};

		let accentsMap = new Map();
		let accentsTpl = '';

		for (let r in accents) {
			accents[r].split('').forEach(a => {
				accentsTpl += a;
				accentsMap.set(a, r);
			});
		}

		let accentsRe = new RegExp(`[${accentsTpl}]`, 'g');
		let replacer = m => accentsMap.get(m);

		return strings => {
			if (typeof strings == 'string')
				return strings.replace(accentsRe, replacer);

			let out = Array(strings.length);
			for (let i = 0; i < strings.length; i++)
				out[i] = strings[i].replace(accentsRe, replacer);
			return out;
		};
	})();

	// https://stackoverflow.com/questions/9960908/permutations-in-javascript/37580979#37580979
	function permute(arr) {
		arr = arr.slice();

		let length = arr.length,
			result = [arr.slice()],
			c = new Array(length).fill(0),
			i = 1, k, p;

		while (i < length) {
			if (c[i] < i) {
				k = i % 2 && c[i];
				p = arr[i];
				arr[i] = arr[k];
				arr[k] = p;
				++c[i];
				i = 1;
				result.push(arr.slice());
			} else {
				c[i] = 0;
				++i;
			}
		}

		return result;
	}

	const _mark = (part, matched) => matched ? `<mark>${part}</mark>` : part;
	const _append = (acc, part) => acc + part;

	function highlight(str, ranges, mark = _mark, accum = '', append = _append) {
		accum = append(accum, mark(str.substring(0, ranges[0]), false)) ?? accum;

		for (let i = 0; i < ranges.length; i+=2) {
			let fr = ranges[i];
			let to = ranges[i+1];

			accum = append(accum, mark(str.substring(fr, to), true)) ?? accum;

			if (i < ranges.length - 3)
				accum = append(accum, mark(str.substring(ranges[i+1], ranges[i+2]), false)) ?? accum;
		}

		accum = append(accum, mark(str.substring(ranges[ranges.length - 1]), false)) ?? accum;

		return accum;
	}

	uFuzzy.latinize = latinize;
	uFuzzy.permute = arr => {
		let idxs = permute([...Array(arr.length).keys()]).sort((a,b) => {
			for (let i = 0; i < a.length; i++) {
				if (a[i] != b[i])
					return a[i] - b[i];
			}
			return 0;
		});

		return idxs.map(pi => pi.map(i => arr[i]));
	};
	uFuzzy.highlight = highlight;

	return uFuzzy;

})();