fairnesscoop /
permacoop
| Total Complexity | 5 |
| Total Lines | 27 |
| Duplicated Lines | 0 % |
| Changes | 0 | ||
| 1 | export class ArrayUtils { |
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| 2 | public static range(start: number, end: number, step = 1) { |
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| 3 | function* generateRange() { |
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| 4 | let x = start - step; |
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| 5 | while (x <= end - step) { |
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| 6 | yield (x += step); |
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| 7 | } |
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| 8 | } |
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| 9 | |||
| 10 | return { |
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| 11 | [Symbol.iterator]: generateRange |
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| 12 | }; |
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| 13 | } |
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| 14 | |||
| 15 | public static zip<T, U>(left: T[], right: U[]): [T, U][] { |
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| 16 | return left.map((value, idx) => [value, right[idx]]); |
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| 17 | } |
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| 18 | |||
| 19 | public static groupBy<T>( |
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| 20 | xs: Array<T>, |
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| 21 | key: (x: T) => string |
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| 22 | ): { [key: string]: T } { |
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| 23 | // Credit: https://stackoverflow.com/a/34890276 |
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| 24 | return xs.reduce(function(rv, x) { |
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| 25 | (rv[key(x)] = rv[key(x)] || []).push(x); |
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| 26 | return rv; |
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| 27 | }, {}); |
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| 28 | } |
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| 30 |
