extra-iterable/index.js

An iterable is a sequence of values.

'use strict';

function IDENTITY(v) {
    return v;
}
function COMPARE(a, b) {
    return a < b ? -1 : (a > b ? 1 : 0);
}

function mod(x, y) {
    return x - y * Math.floor(x / y);
}

const END = Number.MAX_SAFE_INTEGER;
const EMPTY = [].values();
function toSet(x, fm = null) {
    if (!fm)
        return new Set(x);
    var a = new Set(), i = -1;
    for (var v of x)
        a.add(fm(v, ++i, x));
    return a;
}
function is(v) {
    return v != null && typeof v[Symbol.iterator] === "function";
}
function isIterator(v) {
    return v != null && typeof v.next === "function";
}
function isList(v) {
    return is(v) && typeof v !== "string";
}
function iterator(x) {
    return x[Symbol.iterator]();
}
function* keys(x) {
    var i = -1;
    for (var _ of x)
        yield ++i;
}
function* values(x) {
    yield* x;
}
function* entries(x) {
    var i = -1;
    for (var v of x)
        yield [++i, v];
}
function from(x) {
    if (is(x))
        return x;
    return fromIterator(x);
}
function fromIterator(x) {
    return { [Symbol.iterator]: () => x };
}
function* fromRange(v = 0, V = END, dv = 1) {
    for (var n = 0, N = (V - v) / dv; n < N; ++n, v += dv)
        yield v;
}
function* fromInvocation(fn, ...args) {
    for (;;)
        yield fn(...args);
}
function* fromApplication(fm, v) {
    yield v;
    for (var i = 1;; ++i)
        yield v = fm(v, i, null);
}
function isOnce(x) {
    return x[Symbol.iterator]() === x;
}
function isMany(x) {
    return !isOnce(x);
}
function toMany(x, now = false) {
    if (!isOnce(x))
        return x;
    return now ? Array.from(x) : toManyLate(x[Symbol.iterator](), []);
}
function toManyLate(ix, a) {
    return {
        [Symbol.iterator]: () => {
            var i = -1;
            return {
                next: () => {
                    if (++i < a.length)
                        return { value: a[i], done: false };
                    var { value, done } = ix.next();
                    if (!done)
                        a[i] = value;
                    return { value, done };
                }
            };
        }
    };
}
function toInvokable(x) {
    var ix = x[Symbol.iterator]();
    return () => ix.next().value;
}
function isEmpty(x) {
    for (var _ of x)
        return false;
    return true;
}
function length(x, i = 0, I = END) {
    var j = -1, n = 0;
    for (var _ of x)
        if (++j >= i && j < I)
            ++n;
    return n;
}
function index(x, i) {
    var X = length(x);
    return i >= 0 ? Math.min(i, X) : Math.max(X + i, 0);
}
function indexRange(x, i = 0, I = END) {
    var X = length(x);
    var i = i >= 0 ? Math.min(i, X) : Math.max(X + i, 0);
    var I = I >= 0 ? Math.min(I, X) : Math.max(X + I, 0);
    return [i, Math.max(i, I)];
}
function compare(x, y, fc = null, fm = null) {
    var fc = fc || COMPARE;
    var fm = fm || IDENTITY;
    var ix = x[Symbol.iterator]();
    var iy = y[Symbol.iterator]();
    for (var i = 0;; ++i) {
        var u = ix.next();
        var v = iy.next();
        if (u.done || v.done)
            break;
        var u1 = fm(u.value, i, x);
        var v1 = fm(v.value, i, y);
        var c = fc(u1, v1);
        if (c !== 0)
            return c;
    }
    return (v.done ? 1 : 0) - (u.done ? 1 : 0);
}
function isEqual(x, y, fc = null, fm = null) {
    return compare(x, y, fc, fm) === 0;
}
function get(x, i) {
    var j = -1;
    for (var v of x)
        if (++j === i)
            return v;
}
function* getAll(x, is) {
    var i = 0, j = -1;
    var IS = is.length;
    for (var v of x) {
        if (is[i] !== ++j)
            continue;
        do {
            yield v;
        } while (++i < IS && is[i] === is[i - 1]);
        if (i >= IS)
            break;
    }
    for (; i < IS; ++i)
        yield;
}
function getPath(x, p) {
    for (var i of p)
        x = is(x) ? get(x, i) : undefined;
    return x;
}
function hasPath(x, p) {
    return getPath(x, p) !== undefined;
}
function* set(x, i, v) {
    var j = -1;
    for (var u of x)
        yield ++j === i ? v : u;
    if (j >= i)
        return;
    for (; ++j < i;)
        yield;
    yield v;
}
function* swap(x, i, j) {
    if (i === j) {
        yield* x;
        return;
    }
    var k = Math.min(i, j);
    var l = Math.max(i, j);
    var mid = [];
    var vk, i = -1;
    for (var v of x) {
        if (++i < k || i > l)
            yield v;
        else if (i === k)
            vk = v;
        else if (i < l)
            mid.push(v);
        else {
            yield v;
            yield* mid;
            yield vk;
            mid = null;
        }
    }
}
function* remove(x, i) {
    yield* splice(x, i, 1);
}
function count(x, ft) {
    var i = -1, a = 0;
    for (var v of x)
        if (ft(v, ++i, x))
            ++a;
    return a;
}
function countAs(x, fm = null) {
    var fm = fm || IDENTITY;
    var i = -1, a = new Map();
    for (var v of x) {
        var v1 = fm(v, ++i, x);
        a.set(v1, (a.get(v1) || 0) + 1);
    }
    return a;
}
function min(x, fc = null, fm = null) {
    return rangeEntries(x, fc, fm)[0][1];
}
function max(x, fc = null, fm = null) {
    return rangeEntries(x, fc, fm)[1][1];
}
function range(x, fc = null, fm = null) {
    var [a, b] = rangeEntries(x, fc, fm);
    return [a[1], b[1]];
}
function minEntry(x, fc = null, fm = null) {
    return rangeEntries(x, fc, fm)[0];
}
function maxEntry(x, fc = null, fm = null) {
    return rangeEntries(x, fc, fm)[1];
}
function rangeEntries(x, fc = null, fm = null) {
    var fc = fc || COMPARE;
    var fm = fm || IDENTITY;
    var mi = -1, mu, mv;
    var ni = -1, nu, nv;
    var i = -1;
    for (var u of x) {
        var v = fm(u, ++i, x);
        if (i === 0 || fc(v, mv) < 0) {
            mi = i;
            mu = u;
            mv = v;
        }
        if (i === 0 || fc(v, nv) > 0) {
            ni = i;
            nu = u;
            nv = v;
        }
    }
    return [[mi, mu], [ni, nu]];
}
function slice(x, i = 0, I = END) {
    if (i >= 0 && I >= 0)
        return slicePos(x, i, I);
    else if (i >= 0 && I < 0)
        return slicePosNeg(x, i, I);
    else
        return sliceNeg(x, i, I);
}
function* slicePos(x, i, I) {
    var k = -1;
    for (var v of x) {
        if (++k >= I)
            break;
        if (k >= i)
            yield v;
    }
}
function* slicePosNeg(x, i, I) {
    var j = 0, k = -1;
    var a = [], A = -I;
    for (var v of x) {
        if (++k < i)
            continue;
        if (a.length >= A)
            yield a[j];
        a[j] = v;
        j = (j + 1) % A;
    }
}
function* sliceNeg(x, i, I) {
    var j = 0, X = 0;
    var a = [], A = -i;
    for (var v of x) {
        a[j] = v;
        j = (j + 1) % A;
        ++X;
    }
    var i = Math.max(X + i, 0);
    var I = I < 0 ? Math.max(X + I, 0) : Math.min(I, X);
    var n = Math.max(I - i, 0);
    var J = Math.max(j + n - A, 0);
    yield* a.slice(j, j + n);
    yield* a.slice(0, J);
}
function head(x, vd) {
    for (var v of x)
        return v;
    return vd;
}
function last(x, vd) {
    var v = vd;
    for (var v of x)
        ;
    return v;
}
function* tail(x) {
    var i = -1;
    for (var v of x)
        if (++i > 0)
            yield v;
}
function* init(x) {
    var u, i = -1;
    for (var v of x) {
        if (++i > 0)
            yield u;
        u = v;
    }
}
function left(x, n) {
    return slice(x, 0, n);
}
function right(x, n) {
    return n !== 0 ? slice(x, -n) : EMPTY;
}
function middle(x, i, n = 1) {
    return slice(x, i, i + n);
}
function take(x, n = 1) {
    return slice(x, 0, n);
}
function takeRight(x, n = 1) {
    return n > 0 ? slice(x, -n) : EMPTY;
}
function* takeWhile(x, ft) {
    var i = -1;
    for (var v of x) {
        if (ft(v, ++i, x))
            yield v;
        else
            return;
    }
}
function* takeWhileRight(x, ft) {
    var a = [], i = -1;
    for (var v of x) {
        if (ft(v, ++i, x))
            a.push(v);
        else
            a.length = 0;
    }
    yield* a;
}
function drop(x, n = 1) {
    return slice(x, n);
}
function dropRight(x, n = 1) {
    return n > 0 ? slice(x, 0, -n) : values(x);
}
function* dropWhile(x, ft) {
    var c = true, i = -1;
    for (var v of x) {
        c = c && ft(v, ++i, x);
        if (!c)
            yield v;
    }
}
function* dropWhileRight(x, ft) {
    var a = [], i = -1;
    for (var v of x) {
        if (ft(v, ++i, x))
            a.push(v);
        else {
            yield* a;
            yield v;
            a.length = 0;
        }
    }
}
function includes(x, v, i = 0) {
    return hasValue(slice(x, i), v);
}
function indexOf(x, v, i = 0) {
    var a = searchValue(slice(x, i), v);
    return a >= 0 ? a + i : a;
}
function lastIndexOf(x, v, i = END - 1) {
    return searchValueRight(slice(x, 0, i + 1), v);
}
function find(x, ft) {
    var i = -1;
    for (var v of x)
        if (ft(v, ++i, x))
            return v;
}
function findRight(x, ft) {
    var i = -1, a;
    for (var v of x)
        if (ft(v, ++i, x))
            a = v;
    return a;
}
function scanWhile(x, ft) {
    var i = -1;
    for (var v of x)
        if (!ft(v, ++i, x))
            return i;
    return ++i;
}
function scanWhileRight(x, ft) {
    var a = -1, i = -1;
    for (var v of x)
        if (!ft(v, ++i, x))
            a = i;
    return ++a;
}
function scanUntil(x, ft) {
    var i = -1;
    for (var v of x)
        if (ft(v, ++i, x))
            return i;
    return ++i;
}
function scanUntilRight(x, ft) {
    var a = -1, i = -1;
    for (var v of x)
        if (ft(v, ++i, x))
            a = i;
    return ++a;
}
function search(x, ft) {
    var i = -1;
    for (var v of x)
        if (ft(v, ++i, x))
            return i;
    return -1;
}
function searchRight(x, ft) {
    var i = -1, a = -1;
    for (var v of x)
        if (ft(v, ++i, x))
            a = i;
    return a;
}
function* searchAll(x, ft) {
    var i = -1;
    for (var v of x)
        if (ft(v, ++i, x))
            yield i;
}
function searchValue(x, v, fc = null, fm = null) {
    var fc = fc || COMPARE;
    var fm = fm || IDENTITY;
    var v1 = fm(v, 0, null), i = -1;
    for (var u of x) {
        var u1 = fm(u, ++i, x);
        if (fc(u1, v1) === 0)
            return i;
    }
    return -1;
}
function searchValueRight(x, v, fc = null, fm = null) {
    var fc = fc || COMPARE;
    var fm = fm || IDENTITY;
    var v1 = fm(v, 0, null);
    var i = -1, a = -1;
    for (var u of x) {
        var u1 = fm(u, ++i, x);
        if (fc(u1, v1) === 0)
            a = i;
    }
    return a;
}
function* searchValueAll(x, v, fc = null, fm = null) {
    var fc = fc || COMPARE;
    var fm = fm || IDENTITY;
    var v1 = fm(v, 0, null), i = -1;
    for (var u of x) {
        var u1 = fm(u, ++i, x);
        if (fc(u1, v1) === 0)
            yield i;
    }
}
function searchInfix(x, y, fc = null, fm = null) {
    return head(searchInfixAll(x, y, fc, fm), -1);
}
function searchInfixRight(x, y, fc = null, fm = null) {
    return last(searchInfixAll(x, y, fc, fm), -1);
}
function* searchInfixAll(x, y, fc = null, fm = null) {
    var fc = fc || COMPARE;
    var fm = fm || IDENTITY;
    var y1 = [...map(y, fm)];
    var Y = y1.length;
    if (Y === 0) {
        yield* fromRange(0, length(x));
        return;
    }
    var m = new Array(Y).fill(false);
    var i = -1, J = 0;
    for (var u of x) {
        var u1 = fm(u, ++i, x);
        for (var j = J; j > 0; --j)
            m[j] = m[j - 1] && fc(u1, y1[j]) === 0;
        m[0] = fc(u1, y1[0]) === 0;
        J = Math.min(J + 1, Y - 1);
        if (m[Y - 1])
            yield i - Y + 1;
    }
}
function searchSubsequence(x, y, fc = null, fm = null) {
    var fc = fc || COMPARE;
    var fm = fm || IDENTITY;
    var y1 = [...map(y, fm)];
    var Y = y1.length;
    if (Y === 0)
        return 0;
    var si = [], sn = [], i = -1;
    for (var u of x) {
        var u1 = fm(u, ++i, x);
        for (var s = 0, S = si.length; s < S; ++s) {
            var v1 = y1[sn[s]];
            if (fc(u1, v1) !== 0)
                continue;
            if (++sn[s] === Y)
                return si[s];
        }
        var v1 = y1[0];
        if (fc(u1, v1) !== 0)
            continue;
        si.push(i);
        sn.push(1);
    }
    return -1;
}
function hasValue(x, v, fc = null, fm = null) {
    return searchValue(x, v, fc, fm) >= 0;
}
function hasPrefix(x, y, fc = null, fm = null) {
    var fc = fc || COMPARE;
    var fm = fm || IDENTITY;
    var ix = x[Symbol.iterator](), i = -1;
    for (var v of y) {
        var a = ix.next();
        if (a.done)
            return false;
        var u1 = fm(a.value, ++i, x);
        var v1 = fm(v, i, y);
        if (fc(u1, v1) !== 0)
            return false;
    }
    return true;
}
function hasSuffix(x, y, fc = null, fm = null) {
    var fc = fc || COMPARE;
    var fm = fm || IDENTITY;
    var y1 = Array.isArray(y) ? y : [...y];
    var Y = y1.length;
    var a = [], k = 0, n = 0;
    if (Y === 0)
        return true;
    for (var u of x) {
        a[k++ % Y] = u;
        ++n;
    }
    if (a.length < Y)
        return false;
    for (var i = 0, j = n - Y; i < Y; ++i, ++j) {
        var u1 = fm(a[k++ % Y], j, x);
        var v1 = fm(y1[i], i, y);
        if (fc(u1, v1) !== 0)
            return false;
    }
    return true;
}
function hasInfix(x, y, fc = null, fm = null) {
    return searchInfix(x, y, fc, fm) >= 0;
}
function hasSubsequence(x, y, fc = null, fm = null) {
    return searchSubsequence(x, y, fc, fm) >= 0;
}
function forEach(x, fp) {
    var i = -1;
    for (var v of x)
        fp(v, ++i, x);
}
function some(x, ft = null) {
    if (ft)
        return someTest(x, ft);
    else
        return someBoolean(x);
}
function someBoolean(x) {
    for (var v of x)
        if (v)
            return true;
    return false;
}
function someTest(x, ft) {
    var i = -1;
    for (var v of x)
        if (ft(v, ++i, x))
            return true;
    return false;
}
function every(x, ft = null) {
    if (ft)
        return everyTest(x, ft);
    else
        return everyBoolean(x);
}
function everyBoolean(x) {
    for (var v of x)
        if (!v)
            return false;
    return true;
}
function everyTest(x, ft) {
    var i = -1;
    for (var v of x)
        if (!ft(v, ++i, x))
            return false;
    return true;
}
function* map(x, fm) {
    var i = -1;
    for (var v of x)
        yield fm(v, ++i, x);
}
function reduce(x, fr, acc) {
    var init = arguments.length <= 2, i = -1;
    for (var v of x) {
        if (init) {
            init = false;
            acc = v;
            ++i;
        }
        else
            acc = fr(acc, v, ++i, x);
    }
    return acc;
}
function* filter(x, ft) {
    var i = -1;
    for (var v of x)
        if (ft(v, ++i, x))
            yield v;
}
function* filterAt(x, is) {
    var i = -1;
    for (var v of x)
        if (is.includes(++i))
            yield v;
}
function* reject(x, ft) {
    var i = -1;
    for (var v of x)
        if (!ft(v, ++i, x))
            yield v;
}
function* rejectAt(x, is) {
    var i = -1;
    for (var v of x)
        if (!is.includes(++i))
            yield v;
}
function* accumulate(x, fr, acc) {
    var init = arguments.length <= 2, i = -1;
    for (var v of x) {
        if (init) {
            init = false;
            acc = v;
            ++i;
        }
        else
            acc = fr(acc, v, ++i, x);
        yield acc;
    }
}
function* flat(x, n = -1, fm = null, ft = null) {
    var fm = fm || IDENTITY;
    var ft = ft || isList, i = -1;
    for (var v of x) {
        var v1 = fm(v, ++i, x);
        if (n !== 0 && ft(v1, i, x))
            yield* flat(v1, n - 1, fm, ft);
        else
            yield v1;
    }
}
function* flatMap(x, fm = null, ft = null) {
    var fm = fm || IDENTITY;
    var ft = ft || isList, i = -1;
    for (var v of x) {
        var v1 = fm(v, ++i, x);
        if (ft(v1, i, x))
            yield* v1;
        else
            yield v1;
    }
}
function* zip(xs, fm = null, fe = null, vd) {
    var fm = fm || IDENTITY;
    var fe = fe || some;
    var X = xs.length;
    if (X === 0)
        return;
    var ix = [], ds = [], vs = [];
    for (var r = 0; r < X; r++)
        ix[r] = xs[r][Symbol.iterator]();
    for (var i = 0;; ++i) {
        for (var r = 0; r < X; ++r) {
            var { done, value } = ix[r].next();
            ds[r] = done;
            vs[r] = done ? vd : value;
        }
        if (fe(ds))
            break;
        yield fm(vs.slice(), i, null);
    }
}
function* fill(x, v, i = 0, I = END) {
    var j = -1;
    for (var u of x) {
        if (++j >= i && j < I)
            yield v;
        else
            yield u;
    }
}
function* push(x, ...vs) {
    yield* x;
    yield* vs;
}
function* unshift(x, ...vs) {
    yield* vs;
    yield* x;
}
function* copy(x, y, j = 0, i = 0, I = END) {
    var k = -1, J = -1;
    for (var u of x) {
        if (++k === j) {
            J = k;
            for (var v of slice(y, i, I)) {
                yield v;
                ++J;
            }
        }
        if (k >= j && k < J)
            continue;
        else
            yield u;
    }
    if (k < j) {
        for (; ++k < j;)
            yield;
        yield* slice(y, i, I);
    }
}
function* copyWithin(x, j = 0, i = 0, I = END) {
    var x = toMany(x), n = length(x);
    for (var v of copy(x, x, j, i, I)) {
        if (--n < 0)
            break;
        yield v;
    }
}
function moveWithin(x, j = 0, i = 0, I = END) {
    if (j < i)
        return movePart(x, j, i, I);
    else if (j > I)
        return movePart(x, i, I, j);
    else
        return values(x);
}
function* movePart(x, j, k, l) {
    var p = [], i = -1;
    for (var v of x) {
        if (++i < j || i >= l)
            yield v;
        else {
            p.push(v);
            if (i < l - 1)
                continue;
            yield* p.slice(k - j);
            yield* p.slice(0, k - j);
        }
    }
}
function* splice(x, i = 0, n = END - i, ...vs) {
    var j = -1;
    for (var u of x) {
        if (++j < i || j >= i + n)
            yield u;
        else if (j === i)
            yield* vs;
    }
}
function* split(x, ft) {
    var a = [], i = -1;
    for (var v of x) {
        if (!ft(v, ++i, x))
            a.push(v);
        else if (a.length > 0) {
            yield a;
            a = [];
        }
    }
    if (a.length > 0)
        yield a;
}
function* splitAt(x, is) {
    var a = [], i = -1;
    for (var v of x) {
        if (!is.includes(++i))
            a.push(v);
        else if (a.length > 0) {
            yield a;
            a = [];
        }
    }
    if (a.length > 0)
        yield a;
}
function* cut(x, ft) {
    var i = -1, a = [];
    for (var v of x) {
        if (ft(v, ++i, x)) {
            yield a;
            a = [];
        }
        a.push(v);
    }
    yield a;
}
function* cutRight(x, ft) {
    var i = -1, a = [];
    for (var v of x) {
        a.push(v);
        if (ft(v, ++i, x)) {
            yield a;
            a = [];
        }
    }
    yield a;
}
function* cutAt(x, is) {
    var ii = is[Symbol.iterator]();
    var i = ii.next();
    if (i.done)
        i.value = END;
    var a = [], j = -1;
    for (var v of x) {
        if (++j < i.value) {
            a.push(v);
            continue;
        }
        yield a;
        a = [v];
        var i = ii.next();
        if (i.done)
            i.value = END;
    }
    yield a;
    for (; !i.done; i = ii.next())
        yield [];
}
function* cutAtRight(x, is) {
    yield* cutAt(x, map(is, i => i + 1));
}
function* group(x, fc = null, fm = null) {
    var fc = fc || COMPARE;
    var fm = fm || IDENTITY;
    var a = [], u1, i = -1;
    for (var v of x) {
        var v1 = fm(v, ++i, x);
        if (i > 0 && fc(u1, v1) !== 0) {
            yield a;
            a = [v];
        }
        else
            a.push(v);
        u1 = v1;
    }
    yield a;
}
function partition(x, ft) {
    var t = [], f = [], i = -1;
    for (var v of x) {
        if (ft(v, ++i, x))
            t.push(v);
        else
            f.push(v);
    }
    return [t, f];
}
function partitionAs(x, fm = null) {
    var fm = fm || IDENTITY;
    var a = new Map(), i = -1;
    for (var v of x) {
        var v1 = fm(v, ++i, x);
        if (!a.has(v1))
            a.set(v1, []);
        a.get(v1).push(v);
    }
    return a;
}
function* chunk(x, n = 1, s = n) {
    var M = Math.max(n, s);
    var m = 0, a = [];
    for (var v of x) {
        if (m < n)
            a.push(v);
        if (++m < M)
            continue;
        do {
            yield a;
        } while (s <= 0);
        a = a.slice(s);
        m = a.length;
    }
    if (a.length > 0)
        yield a;
}
function* cycle(x, i = 0, n = -1) {
    var x = toMany(x), X = 0;
    if (i < 0) {
        X = length(x);
        if (X === 0)
            return;
        i = mod(i, X);
    }
    while (true) {
        X = 0;
        for (var v of x) {
            ++X;
            if (--i >= 0)
                continue;
            if (n-- === 0)
                return;
            yield v;
        }
        if (X === 0)
            return;
        if (i >= X)
            i = mod(i, X);
    }
}
function* repeat(x, n = -1) {
    var x = toMany(x);
    for (; n !== 0; --n)
        yield* x;
}
function* reverse(x) {
    var a = Array.isArray(x) ? x : [...x];
    for (var i = a.length - 1; i >= 0; --i)
        yield a[i];
}
function rotate(x, n = 0) {
    if (n === 0)
        return values(x);
    else if (n > 0)
        return rotateLeft(x, n);
    else
        return rotateRight(x, -n);
}
function* rotateLeft(x, n) {
    var a = [], i = -1;
    for (var v of x) {
        if (++i < n)
            a.push(v);
        else
            yield v;
    }
    if (++i === 0 || i >= n) {
        yield* a;
        return;
    }
    var n = n % i;
    yield* a.slice(n);
    yield* a.slice(0, n);
}
function* rotateRight(x, n) {
    var a = Array.from(x);
    if (a.length === 0)
        return;
    var n = n % a.length;
    yield* a.slice(-n);
    yield* a.slice(0, -n);
}
function* intersperse(x, v) {
    var i = -1;
    for (var u of x) {
        if (++i > 0)
            yield v;
        yield u;
    }
}
function* interpolate(x, fc) {
    var u, i = -1;
    for (var v of x) {
        if (++i > 0)
            yield fc(u, v);
        yield (u = v);
    }
}
function* intermix(x, y, m = 1, n = 1, s = m, t = n) {
    var x1 = chunk(x, m, s);
    var y1 = chunk(repeat(y), n, t);
    var iy = y1[Symbol.iterator](), i = -1;
    for (var u of x1) {
        if (++i > 0)
            yield* iy.next().value;
        yield* u;
    }
}
function* interleave(xs) {
    var X = xs.length;
    if (X === 0)
        return;
    var ix = [];
    for (var i = 0; i < X; ++i)
        ix[i] = xs[i][Symbol.iterator]();
    for (var i = 0, n = X; n > 0; i = (i + 1) % X) {
        if (ix[i] == null)
            continue;
        var a = ix[i].next();
        if (a.done) {
            ix[i] = null;
            --n;
        }
        else
            yield a.value;
    }
}
function* concat(...xs) {
    for (var x of xs)
        yield* x;
}
function* merge(xs, fc = null, fm = null) {
    var X = xs.length;
    var ix = [], ax = [];
    for (var i = 0, n = 0; n < X; ++n) {
        ix[i] = xs[i][Symbol.iterator]();
        ax[i] = ix[i].next();
        if (!ax[i].done)
            ++i;
    }
    while (i > 0) {
        var as = ax.map(a => a.value);
        var j = minEntry(as, fc, fm)[0];
        yield as[j];
        ax[j] = ix[j].next();
        if (!ax[j].done)
            continue;
        ix.splice(j, 1);
        ax.splice(j, 1);
        --i;
    }
}
function join(x, sep = ",") {
    var a = "";
    for (var v of x)
        a += v + sep;
    return a.substring(0, a.length - sep.length);
}
function isUnique(x, fc = null, fm = null) {
    if (fc)
        return isUniqueDual(x, fc, fm);
    else
        return isUniqueMap(x, fm);
}
function isUniqueMap(x, fm = null) {
    var fm = fm || IDENTITY;
    var x1 = new Set(), i = -1;
    for (var v of x) {
        var v1 = fm(v, ++i, x);
        if (x1.has(v1))
            return false;
        x1.add(v1);
    }
    return true;
}
function isUniqueDual(x, fc = null, fm = null) {
    var fc = fc || COMPARE;
    var fm = fm || IDENTITY;
    var x1 = [...map(x, fm)];
    for (var u1 of x1) {
        for (var v1 of x1)
            if (fc(u1, v1) === 0)
                return false;
    }
    return true;
}
function isDisjoint(x, y, fc = null, fm = null) {
    if (fc)
        return isDisjointDual(x, y, fc, fm);
    else
        return isDisjointMap(x, y, fm);
}
function isDisjointMap(x, y, fm = null) {
    var y1 = toSet(y, fm), i = -1;
    var fm = fm || IDENTITY;
    for (var u of x) {
        var u1 = fm(u, ++i, x);
        if (y1.has(u1))
            return false;
    }
    return true;
}
function isDisjointDual(x, y, fc = null, fm = null) {
    var fc = fc || COMPARE;
    var fm = fm || IDENTITY;
    var y1 = [...map(y, fm)], i = -1;
    for (var u of x) {
        var u1 = fm(u, ++i, x);
        for (var v1 of y1)
            if (fc(u1, v1) === 0)
                return false;
    }
    return true;
}
function* unique(x, fc = null, fm = null) {
    if (fc)
        yield* uniqueDual(x, fc, fm);
    else
        yield* uniqueMap(x, fm);
}
function* uniqueMap(x, fm = null) {
    var fm = fm || IDENTITY;
    var x1 = new Set(), i = -1;
    for (var v of x) {
        var v1 = fm(v, ++i, x);
        if (x1.has(v1))
            continue;
        x1.add(v1);
        yield v;
    }
}
function* uniqueDual(x, fc = null, fm = null) {
    var fc = fc || COMPARE;
    var fm = fm || IDENTITY;
    var x1 = [], i = -1;
    NEXTX: for (var v of x) {
        var v1 = fm(v, ++i, x);
        for (var u1 of x1)
            if (fc(u1, v1) === 0)
                continue NEXTX;
        x1.push(v1);
        yield v;
    }
}
function* union(x, y, fc = null, fm = null) {
    if (fc)
        yield* unionDual(x, y, fc, fm);
    else
        yield* unionMap(x, y, fm);
}
function* unionMap(x, y, fm = null) {
    var fm = fm || IDENTITY;
    var x1 = new Set();
    var i = -1, j = -1;
    for (var u of x) {
        var u1 = fm(u, ++i, x);
        x1.add(u1);
        yield u;
    }
    for (var v of y) {
        var v1 = fm(v, ++j, y);
        if (!x1.has(v1))
            yield v;
    }
}
function* unionDual(x, y, fc = null, fm = null) {
    var fc = fc || COMPARE;
    var fm = fm || IDENTITY;
    var x = toMany(x);
    yield* x;
    var x1 = [...map(x, fm)], j = -1;
    NEXTY: for (var v of y) {
        var v1 = fm(v, ++j, y);
        for (var u1 of x1)
            if (fc(u1, v1) === 0)
                continue NEXTY;
        yield v;
    }
}
function* intersection(x, y, fc = null, fm = null) {
    if (fc)
        yield* intersectionDual(x, y, fc, fm);
    else
        yield* intersectionMap(x, y, fm);
}
function* intersectionMap(x, y, fm = null) {
    var y1 = toSet(y, fm), i = -1;
    var fm = fm || IDENTITY;
    for (var u of x) {
        var u1 = fm(u, ++i, x);
        if (y1.has(u1))
            yield u;
    }
}
function* intersectionDual(x, y, fc = null, fm = null) {
    var fc = fc || COMPARE;
    var fm = fm || IDENTITY;
    var y1 = [...map(y, fm)], i = -1;
    NEXTX: for (var u of x) {
        var u1 = fm(u, ++i, x);
        for (var v1 of y1)
            if (fc(u1, v1) === 0) {
                yield u;
                continue NEXTX;
            }
    }
}
function* difference(x, y, fc = null, fm = null) {
    if (fc)
        yield* differenceDual(x, y, fc, fm);
    else
        yield* differenceMap(x, y, fm);
}
function* differenceMap(x, y, fm = null) {
    var y1 = toSet(y, fm), i = -1;
    var fm = fm || IDENTITY;
    for (var u of x) {
        var u1 = fm(u, ++i, x);
        if (!y1.has(u1))
            yield u;
    }
}
function* differenceDual(x, y, fc = null, fm = null) {
    var fc = fc || COMPARE;
    var fm = fm || IDENTITY;
    var y1 = [...map(y, fm)], i = -1;
    NEXTX: for (var u of x) {
        var u1 = fm(u, ++i, x);
        for (var v1 of y1)
            if (fc(u1, v1) === 0)
                continue NEXTX;
        yield u;
    }
}
function* symmetricDifference(x, y, fc = null, fm = null) {
    var x = toMany(x), y = toMany(y);
    yield* difference(x, y, fc, fm);
    yield* difference(y, x, fc, fm);
}
function* cartesianProduct(xs, fm = null) {
    var fm = fm || IDENTITY;
    var X = xs.length;
    if (X === 0)
        return;
    var jx = [], ix = [], ax = [];
    for (var i = 0; i < X; ++i) {
        jx[i] = i > 0 ? toMany(xs[i]) : xs[i];
        ix[i] = jx[i][Symbol.iterator]();
        ax[i] = ix[i].next();
        if (ax[i].done)
            return;
    }
    for (var i = 0;; ++i) {
        var vs = [];
        for (var a of ax)
            vs.push(a.value);
        yield fm(vs, i, null);
        for (var r = X - 1; r >= 0; --r) {
            ax[r] = ix[r].next();
            if (!ax[r].done)
                break;
            ix[r] = jx[r][Symbol.iterator]();
            ax[r] = ix[r].next();
        }
        if (r < 0)
            break;
    }
}

exports.END = END;
exports.accumulate = accumulate;
exports.callable = toInvokable;
exports.cartesianProduct = cartesianProduct;
exports.chunk = chunk;
exports.compare = compare;
exports.concat = concat;
exports.copy = copy;
exports.copyWithin = copyWithin;
exports.count = count;
exports.countAs = countAs;
exports.cut = cut;
exports.cutAt = cutAt;
exports.cutAtRight = cutAtRight;
exports.cutRight = cutRight;
exports.cycle = cycle;
exports.difference = difference;
exports.drop = drop;
exports.dropRight = dropRight;
exports.dropWhile = dropWhile;
exports.dropWhileRight = dropWhileRight;
exports.entries = entries;
exports.every = every;
exports.fill = fill;
exports.filter = filter;
exports.filterAt = filterAt;
exports.find = find;
exports.findAll = filter;
exports.findRight = findRight;
exports.flat = flat;
exports.flatMap = flatMap;
exports.forEach = forEach;
exports.from = from;
exports.fromApplication = fromApplication;
exports.fromApply = fromApplication;
exports.fromCall = fromInvocation;
exports.fromInvocation = fromInvocation;
exports.fromIterator = fromIterator;
exports.fromRange = fromRange;
exports.get = get;
exports.getAll = getAll;
exports.getPath = getPath;
exports.group = group;
exports.hasInfix = hasInfix;
exports.hasPath = hasPath;
exports.hasPrefix = hasPrefix;
exports.hasSubsequence = hasSubsequence;
exports.hasSuffix = hasSuffix;
exports.hasValue = hasValue;
exports.head = head;
exports.includes = includes;
exports.index = index;
exports.indexOf = indexOf;
exports.indexRange = indexRange;
exports.init = init;
exports.interleave = interleave;
exports.intermix = intermix;
exports.interpolate = interpolate;
exports.intersection = intersection;
exports.intersperse = intersperse;
exports.is = is;
exports.isDisjoint = isDisjoint;
exports.isEmpty = isEmpty;
exports.isEqual = isEqual;
exports.isIterator = isIterator;
exports.isList = isList;
exports.isMany = isMany;
exports.isOnce = isOnce;
exports.isUnique = isUnique;
exports.iterator = iterator;
exports.join = join;
exports.keys = keys;
exports.last = last;
exports.lastIndexOf = lastIndexOf;
exports.left = left;
exports.length = length;
exports.many = toMany;
exports.map = map;
exports.max = max;
exports.maxEntry = maxEntry;
exports.merge = merge;
exports.middle = middle;
exports.min = min;
exports.minEntry = minEntry;
exports.moveWithin = moveWithin;
exports.partition = partition;
exports.partitionAs = partitionAs;
exports.pop = init;
exports.push = push;
exports.range = range;
exports.rangeEntries = rangeEntries;
exports.reduce = reduce;
exports.reject = reject;
exports.rejectAt = rejectAt;
exports.remove = remove;
exports.repeat = repeat;
exports.reverse = reverse;
exports.right = right;
exports.rotate = rotate;
exports.scanUntil = scanUntil;
exports.scanUntilRight = scanUntilRight;
exports.scanWhile = scanWhile;
exports.scanWhileRight = scanWhileRight;
exports.search = search;
exports.searchAll = searchAll;
exports.searchInfix = searchInfix;
exports.searchInfixAll = searchInfixAll;
exports.searchInfixRight = searchInfixRight;
exports.searchRight = searchRight;
exports.searchSubsequence = searchSubsequence;
exports.searchValue = searchValue;
exports.searchValueAll = searchValueAll;
exports.searchValueRight = searchValueRight;
exports.set = set;
exports.shift = tail;
exports.size = length;
exports.slice = slice;
exports.some = some;
exports.splice = splice;
exports.split = split;
exports.splitAt = splitAt;
exports.swap = swap;
exports.symmetricDifference = symmetricDifference;
exports.tail = tail;
exports.take = take;
exports.takeRight = takeRight;
exports.takeWhile = takeWhile;
exports.takeWhileRight = takeWhileRight;
exports.toCallable = toInvokable;
exports.toInvokable = toInvokable;
exports.toMany = toMany;
exports.toOnce = values;
exports.union = union;
exports.unique = unique;
exports.unshift = unshift;
exports.values = values;
exports.zip = zip;