1 | import { curryN, map, range, always } from 'ramda';
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2 | import floor from './floor';
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3 |
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4 | /**
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5 | * Creates an array of numbers (positive and/or negative) progressing from start up to, but not including, end.
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6 | *
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7 | * `Note`: JavaScript follows the IEEE-754 standard for resolving floating-point values which can produce unexpected results.
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8 | *
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9 | * @func rangeStep
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10 | * @memberOf RA
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11 | * @category List
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12 | * @since {@link https://char0n.github.io/ramda-adjunct/2.30.0|v2.30.0}
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13 | * @sig Number -> Number -> Number -> [Number]
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14 | * @param {number} step The value to increment or decrement by
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15 | * @param {number} from The start of the range
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16 | * @param {number} to The end of the range
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17 | * @return {number[]} Returns the range of numbers
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18 | * @see {@link http://ramdajs.com/docs/#range|R.range}
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19 | * @example
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20 | *
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21 | * RA.rangeStep(1, 0, 4); // => [0, 1 ,2, 3]
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22 | * RA.rangeStep(-1, 0, -4); // => [0, -1, -2, -3]
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23 | * RA.rangeStep(1, 1, 5); // => [1, 2, 3, 4]
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24 | * RA.rangeStep(5, 0, 20); // => [0, 5, 10, 15]
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25 | * RA.rangeStep(-1, 0, -4); // => [0, -1, -2, -3]
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26 | * RA.rangeStep(0, 1, 4); // => [1, 1, 1]
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27 | * RA.rangeStep(1, 0, 0); // => []
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28 | */
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29 | var rangeStep = curryN(3, function (step, from, to) {
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30 | var callback = step === 0 ? always(from) : function (n) {
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31 | return from + step * n;
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32 | };
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33 | var rangeEnd = step === 0 ? to - from : floor((to - from) / step);
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34 | return map(callback, range(0, rangeEnd));
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35 | });
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36 | export default rangeStep; |
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