2018-09-06 02:16:08 +09:00
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export function countIf<T>(f: (x: T) => boolean, xs: T[]): number {
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return xs.filter(f).length;
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}
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export function count<T>(x: T, xs: T[]): number {
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return countIf(y => x === y, xs);
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}
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2018-09-06 02:28:04 +09:00
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export function intersperse<T>(sep: T, xs: T[]): T[] {
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return [].concat(...xs.map(x => [sep, x])).slice(1);
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}
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