Implement Collection

.gitea/workflows/main.yaml

@@ -30,4 +30,4 @@ jobs:
       - name: Publish
         run: npm publish
         env:
-          INFENDRO__TOKEN: ${{ secrets.token }}
+          TOKEN: ${{ secrets.token }}

.npmrc

@@ -1,2 +1,2 @@
 @infendro:registry=https://git.infendro.com/api/packages/Infendro/npm/
-//git.infendro.com/api/packages/Infendro/npm/:_authToken="${INFENDRO__TOKEN}"
+//git.infendro.com/api/packages/Infendro/npm/:_authToken="${TOKEN}"

package-lock.json

@@ -1,11 +1,11 @@
 {
-  "name": "@infendro/sequence",
+  "name": "@infendro/collection",
   "version": "0.0.1",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
-      "name": "@infendro/sequence",
+      "name": "@infendro/collection",
       "version": "0.0.1",
       "devDependencies": {
         "typescript": "^6.0.3"

package.json

@@ -1,5 +1,5 @@
 {
-  "name": "@infendro/sequence",
+  "name": "@infendro/collection",
   "version": "0.0.1",
   "scripts": {
     "build": "tsc"

src/collection.ts

@@ -0,0 +1,434 @@
+import {all} from "./collection/all";
+import {any} from "./collection/any";
+import {associate} from "./collection/associate";
+import {associateBy} from "./collection/associateBy";
+import {associateWith} from "./collection/associateWith";
+import {average} from "./collection/average";
+import {averageBy} from "./collection/averageBy";
+import {averageByOrNull} from "./collection/averageByOrNull";
+import {averageOrNull} from "./collection/averageOrNull";
+import {chunked} from "./collection/chunked";
+import {contains} from "./collection/contains";
+import {containsAll} from "./collection/containsAll";
+import {count} from "./collection/count";
+import {distinct} from "./collection/distinct";
+import {distinctBy} from "./collection/distinctBy";
+import {drop} from "./collection/drop";
+import {dropUntil} from "./collection/dropUntil";
+import {dropWhile} from "./collection/dropWhile";
+import {filter} from "./collection/filter";
+import {first} from "./collection/first";
+import {firstOrNull} from "./collection/firstOrNull";
+import {flatMap} from "./collection/flatMap";
+import {flatten} from "./collection/flatten";
+import {fold} from "./collection/fold";
+import {forEach} from "./collection/forEach";
+import {get} from "./collection/get";
+import {getOrNull} from "./collection/getOrNull";
+import {groupBy} from "./collection/groupBy";
+import {indices} from "./collection/indices";
+import {intersect} from "./collection/intersect";
+import {isEmpty} from "./collection/isEmpty";
+import {isNotEmpty} from "./collection/isNotEmpty";
+import {joinToString} from "./collection/joinToString";
+import {last} from "./collection/last";
+import {lastOrNull} from "./collection/lastOrNull";
+import {map} from "./collection/map";
+import {mapNotNull} from "./collection/mapNotNull";
+import {max} from "./collection/max";
+import {maxBy} from "./collection/maxBy";
+import {maxByOrNull} from "./collection/maxByOrNull";
+import {maxOf} from "./collection/maxOf";
+import {maxOfOrNull} from "./collection/maxOfOrNull";
+import {maxOrNull} from "./collection/maxOrNull";
+import {maxWith} from "./collection/maxWith";
+import {maxWithOrNull} from "./collection/maxWithOrNull";
+import {min} from "./collection/min";
+import {minBy} from "./collection/minBy";
+import {minByOrNull} from "./collection/minByOrNull";
+import {minOf} from "./collection/minOf";
+import {minOfOrNull} from "./collection/minOfOrNull";
+import {minOrNull} from "./collection/minOrNull";
+import {minWith} from "./collection/minWith";
+import {minWithOrNull} from "./collection/minWithOrNull";
+import {minus} from "./collection/minus";
+import {none} from "./collection/none";
+import {onEach} from "./collection/onEach";
+import {partition} from "./collection/partition";
+import {plus} from "./collection/plus";
+import {reduce} from "./collection/reduce";
+import {reduceOrNull} from "./collection/reduceOrNull";
+import {reversed} from "./collection/reversed";
+import {scan} from "./collection/scan";
+import {single} from "./collection/single";
+import {singleOrNull} from "./collection/singleOrNull";
+import {slice} from "./collection/slice";
+import {sorted} from "./collection/sorted";
+import {sortedBy} from "./collection/sortedBy";
+import {sortedWith} from "./collection/sortedWith";
+import {sum} from "./collection/sum";
+import {sumBy} from "./collection/sumBy";
+import {take} from "./collection/take";
+import {takeUntil} from "./collection/takeUntil";
+import {takeWhile} from "./collection/takeWhile";
+import {toArray} from "./collection/toArray";
+import {toMap} from "./collection/toMap";
+import {toSet} from "./collection/toSet";
+import {unzip} from "./collection/unzip";
+import {windowed} from "./collection/windowed";
+import {withIndex} from "./collection/withIndex";
+import {zip} from "./collection/zip";
+
+export type Collection<T> = {
+    [Symbol.iterator](): Iterator<T>
+
+    toArray(): T[]
+    toSet(): Set<T>
+    toMap<K, V>(this: Collection<[K, V]>): Map<K, V>
+
+    onEach(action: (it: T) => void): Collection<T>
+    forEach(action: (it: T) => void): void
+
+    isEmpty(): boolean
+    isNotEmpty(): boolean
+    count(predicate?: (it: T) => boolean): number
+
+    indices(): Collection<number>
+    withIndex(): Collection<[number, T]>
+
+    contains(item: T): boolean
+    containsAll(items: Iterable<T>): boolean
+    any(predicate: (it: T) => boolean): boolean
+    all(predicate: (it: T) => boolean): boolean
+    none(predicate: (it: T) => boolean): boolean
+
+    get(index: number): T
+    getOrNull(index: number): T | null
+    first(predicate?: (it: T) => boolean): T
+    firstOrNull(predicate?: (it: T) => boolean): T | null
+    last(predicate?: (it: T) => boolean): T
+    lastOrNull(predicate?: (it: T) => boolean): T | null
+    single(predicate?: (it: T) => boolean): T
+    singleOrNull(predicate?: (it: T) => boolean): T | null
+
+    reduce(accumulate: (acc: T, it: T) => T): T
+    reduceOrNull(accumulate: (acc: T, it: T) => T): T | null
+    fold<R>(initial: R, accumulate: (acc: R, it: T) => R): R
+    scan<R>(initial: R, accumulate: (acc: R, it: T) => R): Collection<R>
+    sum(this: Collection<number>): number
+    sumBy(transform: (it: T) => number): number
+    average(this: Collection<number>): number
+    averageOrNull(this: Collection<number>): number | null
+    averageBy(transform: (it: T) => number): number
+    averageByOrNull(transform: (it: T) => number): number | null
+
+    min(this: Collection<number>): number
+    minOrNull(this: Collection<number>): number | null
+    minWith(compare: (a: T, b: T) => number): T
+    minWithOrNull(compare: (a: T, b: T) => number): T | null
+    minBy(transform: (it: T) => number): T
+    minByOrNull(transform: (it: T) => number): T | null
+    minOf(transform: (it: T) => number): number
+    minOfOrNull(transform: (it: T) => number): number | null
+
+    max(this: Collection<number>): number
+    maxOrNull(this: Collection<number>): number | null
+    maxWith(compare: (a: T, b: T) => number): T
+    maxWithOrNull(compare: (a: T, b: T) => number): T | null
+    maxBy(transform: (it: T) => number): T
+    maxByOrNull(transform: (it: T) => number): T | null
+    maxOf(transform: (it: T) => number): number
+    maxOfOrNull(transform: (it: T) => number): number | null
+
+    joinToString(separator: string, transform?: (it: T) => string): string
+
+    plus(items: Iterable<T>): Collection<T>
+    minus(items: Iterable<T>): Collection<T>
+    intersect(items: Iterable<T>): Collection<T>
+
+    filter<R extends T>(predicate: (it: T) => it is R): Collection<R>
+    filter(predicate: (it: T) => boolean): Collection<T>
+    partition(predicate: (it: T) => boolean): [T[], T[]]
+    distinct(): Collection<T>
+    distinctBy<K>(transform: (it: T) => K): Collection<T>
+
+    drop(count: number): Collection<T>
+    dropWhile(predicate: (it: T) => boolean): Collection<T>
+    dropUntil(predicate: (it: T) => boolean): Collection<T>
+    take(count: number): Collection<T>
+    takeWhile(predicate: (it: T) => boolean): Collection<T>
+    takeUntil(predicate: (it: T) => boolean): Collection<T>
+    slice(start: number, end?: number): Collection<T>
+
+    map<R>(transform: (it: T) => R): Collection<R>
+    mapNotNull<R>(transform: (it: T) => R | null): Collection<R>
+    flatten<R>(this: Collection<Iterable<R>>): Collection<R>
+    flatMap<R>(transform: (it: T) => Iterable<R>): Collection<R>
+
+    groupBy<K>(transform: (it: T) => K): Collection<[K, T[]]>
+    associate<K, V>(transform: (it: T) => [K, V]): Collection<[K, V]>
+    associateBy<K>(transform: (it: T) => K): Collection<[K, T]>
+    associateWith<V>(transform: (it: T) => V): Collection<[T, V]>
+    zip<B>(items: Iterable<B>): Collection<[T, B]>
+    unzip<A, B>(this: Collection<[A, B]>): [A[], B[]]
+
+    windowed(size: number, step?: number, partial?: boolean): Collection<T[]>
+    chunked(size: number): Collection<T[]>
+
+    reversed(): Collection<T>
+    sorted(this: Collection<number>): Collection<number>
+    sortedWith(compare: (a: T, b: T) => number): Collection<T>
+    sortedBy(transform: (it: T) => number): Collection<T>
+}
+
+export function collection<T>(value: Iterable<T>): Collection<T> {
+    return wrap([...value]);
+}
+
+function wrap<T>(value: T[]): Collection<T> {
+    return {
+        [Symbol.iterator]() {
+            return value[Symbol.iterator]();
+        },
+        toArray() {
+            return toArray(value);
+        },
+        toSet() {
+            return toSet(value);
+        },
+        toMap<K, V>() {
+            return toMap(value as [K, V][]);
+        },
+        onEach(action) {
+            return wrap(onEach(value, action));
+        },
+        forEach(action) {
+            forEach(value, action);
+        },
+        isEmpty() {
+            return isEmpty(value);
+        },
+        isNotEmpty() {
+            return isNotEmpty(value);
+        },
+        count(predicate) {
+            return count(value, predicate);
+        },
+        indices() {
+            return wrap(indices(value));
+        },
+        withIndex() {
+            return wrap(withIndex(value));
+        },
+        contains(item) {
+            return contains(value, item);
+        },
+        containsAll(items) {
+            return containsAll(value, items);
+        },
+        any(predicate) {
+            return any(value, predicate);
+        },
+        all(predicate) {
+            return all(value, predicate);
+        },
+        none(predicate) {
+            return none(value, predicate);
+        },
+        get(index) {
+            return get(value, index);
+        },
+        getOrNull(index) {
+            return getOrNull(value, index);
+        },
+        first(predicate) {
+            return first(value, predicate);
+        },
+        firstOrNull(predicate) {
+            return firstOrNull(value, predicate);
+        },
+        last(predicate) {
+            return last(value, predicate);
+        },
+        lastOrNull(predicate) {
+            return lastOrNull(value, predicate);
+        },
+        single(predicate) {
+            return single(value, predicate);
+        },
+        singleOrNull(predicate) {
+            return singleOrNull(value, predicate);
+        },
+        reduce(accumulate) {
+            return reduce(value, accumulate);
+        },
+        reduceOrNull(accumulate) {
+            return reduceOrNull(value, accumulate);
+        },
+        fold(initial, accumulate) {
+            return fold(value, initial, accumulate);
+        },
+        scan(initial, accumulate) {
+            return wrap(scan(value, initial, accumulate));
+        },
+        sum() {
+            return sum(value as number[]);
+        },
+        sumBy(transform) {
+            return sumBy(value, transform);
+        },
+        average() {
+            return average(value as number[]);
+        },
+        averageOrNull() {
+            return averageOrNull(value as number[]);
+        },
+        averageBy(transform) {
+            return averageBy(value, transform);
+        },
+        averageByOrNull(transform) {
+            return averageByOrNull(value, transform);
+        },
+        min() {
+            return min(value as number[]);
+        },
+        minOrNull() {
+            return minOrNull(value as number[]);
+        },
+        minWith(compare) {
+            return minWith(value, compare);
+        },
+        minWithOrNull(compare) {
+            return minWithOrNull(value, compare);
+        },
+        minBy(transform) {
+            return minBy(value, transform);
+        },
+        minByOrNull(transform) {
+            return minByOrNull(value, transform);
+        },
+        minOf(transform) {
+            return minOf(value, transform);
+        },
+        minOfOrNull(transform) {
+            return minOfOrNull(value, transform);
+        },
+        max() {
+            return max(value as number[]);
+        },
+        maxOrNull() {
+            return maxOrNull(value as number[]);
+        },
+        maxWith(compare) {
+            return maxWith(value, compare);
+        },
+        maxWithOrNull(compare) {
+            return maxWithOrNull(value, compare);
+        },
+        maxBy(transform) {
+            return maxBy(value, transform);
+        },
+        maxByOrNull(transform) {
+            return maxByOrNull(value, transform);
+        },
+        maxOf(transform) {
+            return maxOf(value, transform);
+        },
+        maxOfOrNull(transform) {
+            return maxOfOrNull(value, transform);
+        },
+        joinToString(separator, transform) {
+            return joinToString(value, separator, transform);
+        },
+        plus(items) {
+            return wrap(plus(value, items));
+        },
+        minus(items) {
+            return wrap(minus(value, items));
+        },
+        intersect(items) {
+            return wrap(intersect(value, items));
+        },
+        filter(predicate: (it: T) => boolean) {
+            return wrap(filter(value, predicate));
+        },
+        partition(predicate) {
+            return partition(value, predicate);
+        },
+        distinct() {
+            return wrap(distinct(value));
+        },
+        distinctBy(transform) {
+            return wrap(distinctBy(value, transform));
+        },
+        drop(count) {
+            return wrap(drop(value, count));
+        },
+        dropWhile(predicate) {
+            return wrap(dropWhile(value, predicate));
+        },
+        dropUntil(predicate) {
+            return wrap(dropUntil(value, predicate));
+        },
+        take(count) {
+            return wrap(take(value, count));
+        },
+        takeWhile(predicate) {
+            return wrap(takeWhile(value, predicate));
+        },
+        takeUntil(predicate) {
+            return wrap(takeUntil(value, predicate));
+        },
+        slice(start, end) {
+            return wrap(slice(value, start, end));
+        },
+        map(transform) {
+            return wrap(map(value, transform));
+        },
+        mapNotNull(transform) {
+            return wrap(mapNotNull(value, transform));
+        },
+        flatten<R>() {
+            return wrap(flatten(value as R[][]));
+        },
+        flatMap(transform) {
+            return wrap(flatMap(value, transform));
+        },
+        groupBy(transform) {
+            return wrap(groupBy(value, transform));
+        },
+        associate(transform) {
+            return wrap(associate(value, transform));
+        },
+        associateBy(transform) {
+            return wrap(associateBy(value, transform));
+        },
+        associateWith(transform) {
+            return wrap(associateWith(value, transform));
+        },
+        zip(items) {
+            return wrap(zip(value, items));
+        },
+        unzip<A, B>() {
+            return unzip(value as [A, B][]);
+        },
+        windowed(size, step, partial) {
+            return wrap(windowed(value, size, step, partial));
+        },
+        chunked(size) {
+            return wrap(chunked(value, size));
+        },
+        reversed() {
+            return wrap(reversed(value));
+        },
+        sorted() {
+            return wrap(sorted(value as number[]));
+        },
+        sortedWith(compare) {
+            return wrap(sortedWith(value, compare));
+        },
+        sortedBy(transform) {
+            return wrap(sortedBy(value, transform));
+        },
+    };
+}

src/collection/all.ts

@@ -0,0 +1,6 @@
+export function all<T>(value: T[], predicate: (it: T) => boolean): boolean {
+    for (const it of value) {
+        if (!predicate(it)) return false;
+    }
+    return true;
+}

src/collection/any.ts

@@ -0,0 +1,6 @@
+export function any<T>(value: T[], predicate: (it: T) => boolean): boolean {
+    for (const it of value) {
+        if (predicate(it)) return true;
+    }
+    return false;
+}

src/collection/associate.ts

@@ -0,0 +1,7 @@
+export function associate<T, K, V>(value: T[], transform: (it: T) => [K, V]): [K, V][] {
+    const result: [K, V][] = [];
+    for (const it of value) {
+        result.push(transform(it));
+    }
+    return result;
+}

src/collection/associateBy.ts

@@ -0,0 +1,7 @@
+export function associateBy<T, K>(value: T[], transform: (it: T) => K): [K, T][] {
+    const result: [K, T][] = [];
+    for (const it of value) {
+        result.push([transform(it), it]);
+    }
+    return result;
+}

src/collection/associateWith.ts

@@ -0,0 +1,7 @@
+export function associateWith<T, V>(value: T[], transform: (it: T) => V): [T, V][] {
+    const result: [T, V][] = [];
+    for (const it of value) {
+        result.push([it, transform(it)]);
+    }
+    return result;
+}

src/collection/average.ts

@@ -0,0 +1,10 @@
+import {error} from "../util/error";
+
+export function average(value: number[]): number {
+    if (value.length === 0) error();
+    let sum = 0;
+    for (const it of value) {
+        sum += it;
+    }
+    return sum / value.length;
+}

src/collection/averageBy.ts

@@ -0,0 +1,10 @@
+import {error} from "../util/error";
+
+export function averageBy<T>(value: T[], transform: (it: T) => number): number {
+    if (value.length === 0) error();
+    let sum = 0;
+    for (const it of value) {
+        sum += transform(it);
+    }
+    return sum / value.length;
+}

src/collection/averageByOrNull.ts

@@ -0,0 +1,8 @@
+export function averageByOrNull<T>(value: T[], transform: (it: T) => number): number | null {
+    if (value.length === 0) return null;
+    let sum = 0;
+    for (const it of value) {
+        sum += transform(it);
+    }
+    return sum / value.length;
+}

src/collection/averageOrNull.ts

@@ -0,0 +1,8 @@
+export function averageOrNull(value: number[]): number | null {
+    if (value.length === 0) return null;
+    let sum = 0;
+    for (const it of value) {
+        sum += it;
+    }
+    return sum / value.length;
+}

src/collection/chunked.ts

@@ -0,0 +1,16 @@
+import {error} from "../util/error";
+
+export function chunked<T>(value: T[], size: number): T[][] {
+    if (size < 1) error();
+    const result: T[][] = [];
+    let buffer: T[] = [];
+    for (const it of value) {
+        buffer.push(it);
+        if (buffer.length === size) {
+            result.push(buffer);
+            buffer = [];
+        }
+    }
+    if (buffer.length !== 0) result.push(buffer);
+    return result;
+}

src/collection/contains.ts

@@ -0,0 +1,6 @@
+export function contains<T>(value: T[], item: T): boolean {
+    for (const it of value) {
+        if (it === item) return true;
+    }
+    return false;
+}

src/collection/containsAll.ts

@@ -0,0 +1,7 @@
+export function containsAll<T>(value: T[], items: Iterable<T>): boolean {
+    const set = new Set(value);
+    for (const it of items) {
+        if (!set.has(it)) return false;
+    }
+    return true;
+}

src/collection/count.ts

@@ -0,0 +1,8 @@
+export function count<T>(value: T[], predicate?: (it: T) => boolean): number {
+    if (!predicate) return value.length;
+    let count = 0;
+    for (const it of value) {
+        if (predicate(it)) count++;
+    }
+    return count;
+}

src/collection/distinct.ts

@@ -0,0 +1,10 @@
+export function distinct<T>(value: T[]): T[] {
+    const result: T[] = [];
+    const set: Set<T> = new Set();
+    for (const it of value) {
+        if (set.has(it)) continue;
+        result.push(it);
+        set.add(it);
+    }
+    return result;
+}

src/collection/distinctBy.ts

@@ -0,0 +1,11 @@
+export function distinctBy<T, K>(value: T[], transform: (it: T) => K): T[] {
+    const result: T[] = [];
+    const set: Set<K> = new Set();
+    for (const it of value) {
+        const x = transform(it);
+        if (set.has(x)) continue;
+        result.push(it);
+        set.add(x);
+    }
+    return result;
+}

src/collection/drop.ts

@@ -0,0 +1,10 @@
+import {error} from "../util/error";
+
+export function drop<T>(value: T[], count: number): T[] {
+    if (count < 0) error();
+    const result: T[] = [];
+    for (let i = count; i < value.length; i++) {
+        result.push(value[i]);
+    }
+    return result;
+}

src/collection/dropUntil.ts

@@ -0,0 +1,11 @@
+export function dropUntil<T>(value: T[], predicate: (it: T) => boolean): T[] {
+    let index = 0;
+    while (index < value.length && !predicate(value[index])) {
+        index++;
+    }
+    const result: T[] = [];
+    for (let i = index; i < value.length; i++) {
+        result.push(value[i]);
+    }
+    return result;
+}

src/collection/dropWhile.ts

@@ -0,0 +1,11 @@
+export function dropWhile<T>(value: T[], predicate: (it: T) => boolean): T[] {
+    let index = 0;
+    while (index < value.length && predicate(value[index])) {
+        index++;
+    }
+    const result: T[] = [];
+    for (let i = index; i < value.length; i++) {
+        result.push(value[i]);
+    }
+    return result;
+}

src/collection/filter.ts

@@ -0,0 +1,7 @@
+export function filter<T>(value: T[], predicate: (it: T) => boolean): T[] {
+    const result: T[] = [];
+    for (const it of value) {
+        if (predicate(it)) result.push(it);
+    }
+    return result;
+}

src/collection/first.ts

@@ -0,0 +1,10 @@
+import {error} from "../util/error";
+
+export function first<T>(value: T[], predicate?: (it: T) => boolean): T {
+    if (value.length === 0) error();
+    if (!predicate) return value[0];
+    for (const it of value) {
+        if (predicate(it)) return it;
+    }
+    error();
+}

src/collection/firstOrNull.ts

@@ -0,0 +1,8 @@
+export function firstOrNull<T>(value: T[], predicate?: (it: T) => boolean): T | null {
+    if (value.length === 0) return null;
+    if (!predicate) return value[0];
+    for (const it of value) {
+        if (predicate(it)) return it;
+    }
+    return null;
+}

src/collection/flatMap.ts

@@ -0,0 +1,7 @@
+export function flatMap<T, R>(value: T[], transform: (it: T) => Iterable<R>): R[] {
+    const result: R[] = [];
+    for (const it of value) {
+        result.push(...transform(it));
+    }
+    return result;
+}

src/collection/flatten.ts

@@ -0,0 +1,7 @@
+export function flatten<R>(value: R[][]): R[] {
+    const result: R[] = [];
+    for (const it of value) {
+        result.push(...it);
+    }
+    return result;
+}

src/collection/fold.ts

@@ -0,0 +1,7 @@
+export function fold<T, R>(value: T[], initial: R, accumulate: (acc: R, it: T) => R): R {
+    let acc = initial;
+    for (const it of value) {
+        acc = accumulate(acc, it);
+    }
+    return acc;
+}

src/collection/forEach.ts

@@ -0,0 +1,5 @@
+export function forEach<T>(value: T[], action: (it: T) => void) {
+    for (const it of value) {
+        action(it);
+    }
+}

src/collection/get.ts

@@ -0,0 +1,6 @@
+import {error} from "../util/error";
+
+export function get<T>(value: T[], index: number): T {
+    if (index < 0 || index >= value.length) error();
+    return value[index];
+}

src/collection/getOrNull.ts

@@ -0,0 +1,4 @@
+export function getOrNull<T>(value: T[], index: number): T | null {
+    if (index < 0 || index >= value.length) return null;
+    return value[index];
+}

src/collection/groupBy.ts

@@ -0,0 +1,9 @@
+export function groupBy<T, K>(value: T[], transform: (it: T) => K): [K, T[]][] {
+    const map: Map<K, T[]> = new Map();
+    for (const it of value) {
+        const key = transform(it);
+        if (!map.has(key)) map.set(key, []);
+        map.get(key)!.push(it);
+    }
+    return [...map];
+}

src/collection/indices.ts

@@ -0,0 +1,7 @@
+export function indices<T>(value: T[]): number[] {
+    const result: number[] = [];
+    for (let index = 0; index < value.length; index++) {
+        result.push(index);
+    }
+    return result;
+}

src/collection/intersect.ts

@@ -0,0 +1,8 @@
+export function intersect<T>(value: T[], items: Iterable<T>): T[] {
+    const result: T[] = [];
+    const set = new Set(items);
+    for (const it of value) {
+        if (set.has(it)) result.push(it);
+    }
+    return result;
+}

src/collection/isEmpty.ts

@@ -0,0 +1,3 @@
+export function isEmpty<T>(value: T[]): boolean {
+    return value.length === 0;
+}

src/collection/isNotEmpty.ts

@@ -0,0 +1,3 @@
+export function isNotEmpty<T>(value: T[]): boolean {
+    return value.length !== 0;
+}

src/collection/joinToString.ts

@@ -0,0 +1,7 @@
+export function joinToString<T>(value: T[], separator: string, transform?: (it: T) => string): string {
+    const transformed: string[] = [];
+    for (const it of value) {
+        transformed.push(transform ? transform(it) : String(it));
+    }
+    return transformed.join(separator);
+}

src/collection/last.ts

@@ -0,0 +1,12 @@
+import {error} from "../util/error";
+
+export function last<T>(value: T[], predicate?: (it: T) => boolean): T {
+    if (value.length === 0) error();
+    if (!predicate) return value[value.length - 1];
+    let last: T | undefined;
+    for (const it of value) {
+        if (predicate(it)) last = it;
+    }
+    if (last === undefined) error();
+    return last;
+}

src/collection/lastOrNull.ts

@@ -0,0 +1,10 @@
+export function lastOrNull<T>(value: T[], predicate?: (it: T) => boolean): T | null {
+    if (value.length === 0) return null;
+    if (!predicate) return value[value.length - 1];
+    let last: T | undefined;
+    for (const it of value) {
+        if (predicate(it)) last = it;
+    }
+    if (last === undefined) return null;
+    return last;
+}

src/collection/map.ts

@@ -0,0 +1,7 @@
+export function map<T, R>(value: T[], transform: (it: T) => R): R[] {
+    const result: R[] = [];
+    for (const it of value) {
+        result.push(transform(it));
+    }
+    return result;
+}

src/collection/mapNotNull.ts

@@ -0,0 +1,8 @@
+export function mapNotNull<T, R>(value: T[], transform: (it: T) => R | null): R[] {
+    const result: R[] = [];
+    for (const it of value) {
+        const transformed = transform(it);
+        if (transformed !== null) result.push(transformed);
+    }
+    return result;
+}

src/collection/max.ts

@@ -0,0 +1,11 @@
+import {error} from "../util/error";
+
+export function max(value: number[]): number {
+    if (value.length === 0) error();
+    let max = value[0];
+    for (let index = 1; index < value.length; index++) {
+        const it = value[index];
+        if (it > max) max = it;
+    }
+    return max;
+}

src/collection/maxBy.ts

@@ -0,0 +1,16 @@
+import {error} from "../util/error";
+
+export function maxBy<T>(value: T[], transform: (it: T) => number): T {
+    if (value.length === 0) error();
+    let max = value[0];
+    let maxVal = transform(max);
+    for (let index = 1; index < value.length; index++) {
+        const it = value[index];
+        const val = transform(it);
+        if (val > maxVal) {
+            max = it;
+            maxVal = val;
+        }
+    }
+    return max;
+}

src/collection/maxByOrNull.ts

@@ -0,0 +1,14 @@
+export function maxByOrNull<T>(value: T[], transform: (it: T) => number): T | null {
+    if (value.length === 0) return null;
+    let max = value[0];
+    let maxVal = transform(max);
+    for (let index = 1; index < value.length; index++) {
+        const it = value[index];
+        const val = transform(it);
+        if (val > maxVal) {
+            max = it;
+            maxVal = val;
+        }
+    }
+    return max;
+}

src/collection/maxOf.ts

@@ -0,0 +1,12 @@
+import {error} from "../util/error";
+
+export function maxOf<T>(value: T[], transform: (it: T) => number): number {
+    if (value.length === 0) error();
+    let max = transform(value[0]);
+    for (let index = 1; index < value.length; index++) {
+        const it = value[index];
+        const val = transform(it);
+        if (val > max) max = val;
+    }
+    return max;
+}

src/collection/maxOfOrNull.ts

@@ -0,0 +1,10 @@
+export function maxOfOrNull<T>(value: T[], transform: (it: T) => number): number | null {
+    if (value.length === 0) return null;
+    let max = transform(value[0]);
+    for (let index = 1; index < value.length; index++) {
+        const it = value[index];
+        const val = transform(it);
+        if (val > max) max = val;
+    }
+    return max;
+}

src/collection/maxOrNull.ts

@@ -0,0 +1,9 @@
+export function maxOrNull(value: number[]): number | null {
+    if (value.length === 0) return null;
+    let max = value[0];
+    for (let index = 1; index < value.length; index++) {
+        const it = value[index];
+        if (it > max) max = it;
+    }
+    return max;
+}

src/collection/maxWith.ts

@@ -0,0 +1,11 @@
+import {error} from "../util/error";
+
+export function maxWith<T>(value: T[], compare: (a: T, b: T) => number): T {
+    if (value.length === 0) error();
+    let max = value[0];
+    for (let index = 1; index < value.length; index++) {
+        const it = value[index];
+        if (compare(it, max) > 0) max = it;
+    }
+    return max;
+}

src/collection/maxWithOrNull.ts

@@ -0,0 +1,9 @@
+export function maxWithOrNull<T>(value: T[], compare: (a: T, b: T) => number): T | null {
+    if (value.length === 0) return null;
+    let max = value[0];
+    for (let index = 1; index < value.length; index++) {
+        const it = value[index];
+        if (compare(it, max) > 0) max = it;
+    }
+    return max;
+}

src/collection/min.ts

@@ -0,0 +1,11 @@
+import {error} from "../util/error";
+
+export function min(value: number[]): number {
+    if (value.length === 0) error();
+    let min = value[0];
+    for (let index = 1; index < value.length; index++) {
+        const it = value[index];
+        if (it < min) min = it;
+    }
+    return min;
+}

src/collection/minBy.ts

@@ -0,0 +1,16 @@
+import {error} from "../util/error";
+
+export function minBy<T>(value: T[], transform: (it: T) => number): T {
+    if (value.length === 0) error();
+    let min = value[0];
+    let minVal = transform(min);
+    for (let index = 1; index < value.length; index++) {
+        const it = value[index];
+        const val = transform(it);
+        if (val < minVal) {
+            min = it;
+            minVal = val;
+        }
+    }
+    return min;
+}

src/collection/minByOrNull.ts

@@ -0,0 +1,14 @@
+export function minByOrNull<T>(value: T[], transform: (it: T) => number): T | null {
+    if (value.length === 0) return null;
+    let min = value[0];
+    let minVal = transform(min);
+    for (let index = 1; index < value.length; index++) {
+        const it = value[index];
+        const val = transform(it);
+        if (val < minVal) {
+            min = it;
+            minVal = val;
+        }
+    }
+    return min;
+}

src/collection/minOf.ts

@@ -0,0 +1,12 @@
+import {error} from "../util/error";
+
+export function minOf<T>(value: T[], transform: (it: T) => number): number {
+    if (value.length === 0) error();
+    let min = transform(value[0]);
+    for (let index = 1; index < value.length; index++) {
+        const it = value[index];
+        const val = transform(it);
+        if (val < min) min = val;
+    }
+    return min;
+}

src/collection/minOfOrNull.ts

@@ -0,0 +1,10 @@
+export function minOfOrNull<T>(value: T[], transform: (it: T) => number): number | null {
+    if (value.length === 0) return null;
+    let min = transform(value[0]);
+    for (let index = 1; index < value.length; index++) {
+        const it = value[index];
+        const val = transform(it);
+        if (val < min) min = val;
+    }
+    return min;
+}

src/collection/minOrNull.ts

@@ -0,0 +1,9 @@
+export function minOrNull(value: number[]): number | null {
+    if (value.length === 0) return null;
+    let min = value[0];
+    for (let index = 1; index < value.length; index++) {
+        const it = value[index];
+        if (it < min) min = it;
+    }
+    return min;
+}

src/collection/minWith.ts

@@ -0,0 +1,11 @@
+import {error} from "../util/error";
+
+export function minWith<T>(value: T[], compare: (a: T, b: T) => number): T {
+    if (value.length === 0) error();
+    let min = value[0];
+    for (let index = 1; index < value.length; index++) {
+        const it = value[index];
+        if (compare(it, min) < 0) min = it;
+    }
+    return min;
+}

src/collection/minWithOrNull.ts

@@ -0,0 +1,9 @@
+export function minWithOrNull<T>(value: T[], compare: (a: T, b: T) => number): T | null {
+    if (value.length === 0) return null;
+    let min = value[0];
+    for (let index = 1; index < value.length; index++) {
+        const it = value[index];
+        if (compare(it, min) < 0) min = it;
+    }
+    return min;
+}

src/collection/minus.ts

@@ -0,0 +1,8 @@
+export function minus<T>(value: T[], items: Iterable<T>): T[] {
+    const result: T[] = [];
+    const set = new Set(items);
+    for (const it of value) {
+        if (!set.has(it)) result.push(it);
+    }
+    return result;
+}

src/collection/none.ts

@@ -0,0 +1,6 @@
+export function none<T>(value: T[], predicate: (it: T) => boolean): boolean {
+    for (const it of value) {
+        if (predicate(it)) return false;
+    }
+    return true;
+}

src/collection/onEach.ts

@@ -0,0 +1,6 @@
+export function onEach<T>(value: T[], action: (it: T) => void): T[] {
+    for (const it of value) {
+        action(it);
+    }
+    return value;
+}

src/collection/partition.ts

@@ -0,0 +1,9 @@
+export function partition<T>(value: T[], predicate: (it: T) => boolean): [T[], T[]] {
+    const t: T[] = [];
+    const f: T[] = [];
+    for (const it of value) {
+        if (predicate(it)) t.push(it);
+        else f.push(it);
+    }
+    return [t, f];
+}

src/collection/plus.ts

@@ -0,0 +1,10 @@
+export function plus<T>(value: T[], items: Iterable<T>): T[] {
+    const result: T[] = [];
+    for (const it of value) {
+        result.push(it);
+    }
+    for (const it of items) {
+        result.push(it);
+    }
+    return result;
+}

src/collection/reduce.ts

@@ -0,0 +1,10 @@
+import {error} from "../util/error";
+
+export function reduce<T>(value: T[], accumulate: (acc: T, it: T) => T): T {
+    if (value.length === 0) error();
+    let acc = value[0];
+    for (let index = 1; index < value.length; index++) {
+        acc = accumulate(acc, value[index]);
+    }
+    return acc;
+}

src/collection/reduceOrNull.ts

@@ -0,0 +1,8 @@
+export function reduceOrNull<T>(value: T[], accumulate: (acc: T, it: T) => T): T | null {
+    if (value.length === 0) return null;
+    let acc = value[0];
+    for (let index = 1; index < value.length; index++) {
+        acc = accumulate(acc, value[index]);
+    }
+    return acc;
+}

src/collection/reversed.ts

@@ -0,0 +1,3 @@
+export function reversed<T>(value: T[]): T[] {
+    return [...value].reverse();
+}

src/collection/scan.ts

@@ -0,0 +1,9 @@
+export function scan<T, R>(value: T[], initial: R, accumulate: (acc: R, it: T) => R): R[] {
+    const result: R[] = [initial];
+    let acc = initial;
+    for (const it of value) {
+        acc = accumulate(acc, it);
+        result.push(acc);
+    }
+    return result;
+}

src/collection/single.ts

@@ -0,0 +1,18 @@
+import {error} from "../util/error";
+
+export function single<T>(value: T[], predicate?: (it: T) => boolean): T {
+    if (value.length === 0) error();
+    if (!predicate) {
+        if (value.length !== 1) error();
+        return value[0];
+    }
+    let last: T | undefined;
+    for (const it of value) {
+        if (predicate(it)) {
+            if (last !== undefined) error();
+            last = it;
+        }
+    }
+    if (last === undefined) error();
+    return last;
+}

src/collection/singleOrNull.ts

@@ -0,0 +1,16 @@
+export function singleOrNull<T>(value: T[], predicate?: (it: T) => boolean): T | null {
+    if (value.length === 0) return null;
+    if (!predicate) {
+        if (value.length !== 1) return null;
+        return value[0];
+    }
+    let last: T | undefined;
+    for (const it of value) {
+        if (predicate(it)) {
+            if (last !== undefined) return null;
+            last = it;
+        }
+    }
+    if (last === undefined) return null;
+    return last;
+}

src/collection/slice.ts

@@ -0,0 +1,15 @@
+import {error} from "../util/error";
+
+export function slice<T>(value: T[], start: number, end?: number): T[] {
+    if (start < 0) error();
+    if (end !== undefined) {
+        if (end < 0 || end > value.length) error();
+        if (start > end) error();
+    }
+    const result: T[] = [];
+    const limit = end ?? value.length;
+    for (let index = start; index < limit; index++) {
+        result.push(value[index]);
+    }
+    return result;
+}

src/collection/sorted.ts

@@ -0,0 +1,3 @@
+export function sorted(value: number[]): number[] {
+    return [...value].sort((a, b) => a - b);
+}

src/collection/sortedBy.ts

@@ -0,0 +1,3 @@
+export function sortedBy<T>(value: T[], transform: (it: T) => number): T[] {
+    return [...value].sort((a, b) => transform(a) - transform(b));
+}

src/collection/sortedWith.ts

@@ -0,0 +1,3 @@
+export function sortedWith<T>(value: T[], compare: (a: T, b: T) => number): T[] {
+    return [...value].sort(compare);
+}

src/collection/sum.ts

@@ -0,0 +1,7 @@
+export function sum(value: number[]): number {
+    let sum = 0;
+    for (const it of value) {
+        sum += it;
+    }
+    return sum;
+}

src/collection/sumBy.ts

@@ -0,0 +1,7 @@
+export function sumBy<T>(value: T[], transform: (it: T) => number): number {
+    let sum = 0;
+    for (const it of value) {
+        sum += transform(it);
+    }
+    return sum;
+}

src/collection/take.ts

@@ -0,0 +1,11 @@
+import {error} from "../util/error";
+
+export function take<T>(value: T[], count: number): T[] {
+    if (count < 0) error();
+    const result: T[] = [];
+    const limit = Math.min(count, value.length);
+    for (let index = 0; index < limit; index++) {
+        result.push(value[index]);
+    }
+    return result;
+}

src/collection/takeUntil.ts

@@ -0,0 +1,8 @@
+export function takeUntil<T>(value: T[], predicate: (it: T) => boolean): T[] {
+    const result: T[] = [];
+    for (const it of value) {
+        if (predicate(it)) break;
+        result.push(it);
+    }
+    return result;
+}

src/collection/takeWhile.ts

@@ -0,0 +1,8 @@
+export function takeWhile<T>(value: Iterable<T>, predicate: (it: T) => boolean): T[] {
+    const result: T[] = [];
+    for (const it of value) {
+        if (!predicate(it)) break;
+        result.push(it);
+    }
+    return result;
+}

src/collection/toArray.ts

@@ -0,0 +1,3 @@
+export function toArray<T>(value: T[]): T[] {
+    return [...value];
+}

src/collection/toMap.ts

@@ -0,0 +1,3 @@
+export function toMap<K, V>(value: [K, V][]): Map<K, V> {
+    return new Map(value);
+}

src/collection/toSet.ts

@@ -0,0 +1,3 @@
+export function toSet<T>(value: T[]): Set<T> {
+    return new Set(value);
+}

src/collection/unzip.ts

@@ -0,0 +1,9 @@
+export function unzip<A, B>(value: [A, B][]): [A[], B[]] {
+    const resultA: A[] = [];
+    const resultB: B[] = [];
+    for (const [a, b] of value) {
+        resultA.push(a);
+        resultB.push(b);
+    }
+    return [resultA, resultB];
+}

src/collection/windowed.ts

@@ -0,0 +1,22 @@
+import {error} from "../util/error";
+
+export function windowed<T>(value: T[], size: number, step: number = 1, partial: boolean = false): T[][] {
+    if (size < 1) error();
+    if (step < 1) error();
+    const result: T[][] = [];
+    const buffer: T[] = [];
+    for (const it of value) {
+        buffer.push(it);
+        if (buffer.length === size) {
+            result.push([...buffer]);
+            buffer.splice(0, step);
+        }
+    }
+    if (partial) {
+        while (buffer.length !== 0) {
+            result.push([...buffer]);
+            buffer.splice(0, step);
+        }
+    }
+    return result;
+}

src/collection/withIndex.ts

@@ -0,0 +1,7 @@
+export function withIndex<T>(value: T[]): [number, T][] {
+    const result: [number, T][] = [];
+    for (let index = 0; index < value.length; index++) {
+        result.push([index, value[index]]);
+    }
+    return result;
+}

src/collection/zip.ts

@@ -0,0 +1,13 @@
+export function zip<T, B>(value: T[], items: Iterable<B>): [T, B][] {
+    const result: [T, B][] = [];
+    const iteratorA = value[Symbol.iterator]();
+    const iteratorB = items[Symbol.iterator]();
+    let a = iteratorA.next();
+    let b = iteratorB.next();
+    while (!a.done && !b.done) {
+        result.push([a.value, b.value]);
+        a = iteratorA.next();
+        b = iteratorB.next();
+    }
+    return result;
+}

src/index.ts

@@ -0,0 +1 @@
+export {type Collection, collection} from "./collection";

src/util/error.ts

@@ -0,0 +1,3 @@
+export function error(message?: string): never {
+    throw Error(message);
+}

tsconfig.json

@@ -1,11 +1,10 @@
 {
   "compilerOptions": {
-    "moduleResolution": "NodeNext",
-    "module": "NodeNext",
-    "target": "ESNext",
     "rootDir": "./src/",
+    "target": "ESNext",
+    "module": "ESNext",
+    "moduleResolution": "bundler",
     "outDir": "./dist/",
-    "declaration": true,
+    "declaration": true
-    "strict": true
   }
 }