| Leo Repp | 58b9f11 | 2021-11-22 11:57:47 +0100 | [diff] [blame^] | 1 | /** Used as references for various `Number` constants. */ |
| 2 | var MAX_SAFE_INTEGER = 9007199254740991; |
| 3 | |
| 4 | /* Built-in method references for those with the same name as other `lodash` methods. */ |
| 5 | var nativeFloor = Math.floor; |
| 6 | |
| 7 | /** |
| 8 | * The base implementation of `_.repeat` which doesn't coerce arguments. |
| 9 | * |
| 10 | * @private |
| 11 | * @param {string} string The string to repeat. |
| 12 | * @param {number} n The number of times to repeat the string. |
| 13 | * @returns {string} Returns the repeated string. |
| 14 | */ |
| 15 | function baseRepeat(string, n) { |
| 16 | var result = ''; |
| 17 | if (!string || n < 1 || n > MAX_SAFE_INTEGER) { |
| 18 | return result; |
| 19 | } |
| 20 | // Leverage the exponentiation by squaring algorithm for a faster repeat. |
| 21 | // See https://en.wikipedia.org/wiki/Exponentiation_by_squaring for more details. |
| 22 | do { |
| 23 | if (n % 2) { |
| 24 | result += string; |
| 25 | } |
| 26 | n = nativeFloor(n / 2); |
| 27 | if (n) { |
| 28 | string += string; |
| 29 | } |
| 30 | } while (n); |
| 31 | |
| 32 | return result; |
| 33 | } |
| 34 | |
| 35 | module.exports = baseRepeat; |