1 | ;
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2 | Object.defineProperty(exports, "__esModule", { value: true });
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3 | /*-----------------------------------------------------------------------------
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4 | | Copyright (c) 2014-2017, PhosphorJS Contributors
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5 | |
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6 | | Distributed under the terms of the BSD 3-Clause License.
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7 | |
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8 | | The full license is in the file LICENSE, distributed with this software.
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9 | |----------------------------------------------------------------------------*/
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10 | var iter_1 = require("./iter");
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11 | /**
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12 | * Iterate over an iterable using a stepped increment.
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13 | *
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14 | * @param object - The iterable or array-like object of interest.
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15 | *
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16 | * @param step - The distance to step on each iteration. A value
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17 | * of less than `1` will behave the same as a value of `1`.
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18 | *
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19 | * @returns An iterator which traverses the iterable step-wise.
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20 | *
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21 | * #### Example
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22 | * ```typescript
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23 | * import { stride, toArray } from '@phosphor/algorithm';
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24 | *
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25 | * let data = [1, 2, 3, 4, 5, 6];
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26 | *
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27 | * let stream = stride(data, 2);
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28 | *
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29 | * toArray(stream); // [1, 3, 5];
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30 | * ```
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31 | */
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32 | function stride(object, step) {
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33 | return new StrideIterator(iter_1.iter(object), step);
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34 | }
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35 | exports.stride = stride;
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36 | /**
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37 | * An iterator which traverses a source iterator step-wise.
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38 | */
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39 | var StrideIterator = /** @class */ (function () {
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40 | /**
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41 | * Construct a new stride iterator.
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42 | *
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43 | * @param source - The iterator of values of interest.
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44 | *
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45 | * @param step - The distance to step on each iteration. A value
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46 | * of less than `1` will behave the same as a value of `1`.
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47 | */
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48 | function StrideIterator(source, step) {
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49 | this._source = source;
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50 | this._step = step;
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51 | }
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52 | /**
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53 | * Get an iterator over the object's values.
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54 | *
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55 | * @returns An iterator which yields the object's values.
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56 | */
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57 | StrideIterator.prototype.iter = function () {
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58 | return this;
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59 | };
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60 | /**
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61 | * Create an independent clone of the iterator.
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62 | *
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63 | * @returns A new independent clone of the iterator.
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64 | */
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65 | StrideIterator.prototype.clone = function () {
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66 | return new StrideIterator(this._source.clone(), this._step);
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67 | };
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68 | /**
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69 | * Get the next value from the iterator.
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70 | *
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71 | * @returns The next value from the iterator, or `undefined`.
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72 | */
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73 | StrideIterator.prototype.next = function () {
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74 | var value = this._source.next();
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75 | for (var n = this._step - 1; n > 0; --n) {
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76 | this._source.next();
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77 | }
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78 | return value;
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79 | };
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80 | return StrideIterator;
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81 | }());
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82 | exports.StrideIterator = StrideIterator;
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