iceshrimp-161sh/src/prelude/array.ts
2018-09-07 00:02:55 +09:00

20 lines
460 B
TypeScript

export function countIf<T>(f: (x: T) => boolean, xs: T[]): number {
return xs.filter(f).length;
}
export function count<T>(x: T, xs: T[]): number {
return countIf(y => x === y, xs);
}
export function concat<T>(xss: T[][]): T[] {
return ([] as T[]).concat(...xss);
}
export function intersperse<T>(sep: T, xs: T[]): T[] {
return concat(xs.map(x => [sep, x])).slice(1);
}
export function erase<T>(x: T, xs: T[]): T[] {
return xs.filter(y => x !== y);
}