1 | import _checkForMethod from "./internal/_checkForMethod.js";
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2 | import _curry2 from "./internal/_curry2.js";
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3 | import reduceBy from "./reduceBy.js";
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4 | /**
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5 | * Splits a list into sub-lists stored in an object, based on the result of
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6 | * calling a String-returning function on each element, and grouping the
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7 | * results according to values returned.
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8 | *
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9 | * Dispatches to the `groupBy` method of the second argument, if present.
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10 | *
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11 | * Acts as a transducer if a transformer is given in list position.
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12 | *
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13 | * @func
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14 | * @memberOf R
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15 | * @since v0.1.0
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16 | * @category List
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17 | * @sig (a -> String) -> [a] -> {String: [a]}
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18 | * @param {Function} fn Function :: a -> String
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19 | * @param {Array} list The array to group
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20 | * @return {Object} An object with the output of `fn` for keys, mapped to arrays of elements
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21 | * that produced that key when passed to `fn`.
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22 | * @see R.reduceBy, R.transduce
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23 | * @example
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24 | *
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25 | * const byGrade = R.groupBy(function(student) {
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26 | * const score = student.score;
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27 | * return score < 65 ? 'F' :
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28 | * score < 70 ? 'D' :
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29 | * score < 80 ? 'C' :
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30 | * score < 90 ? 'B' : 'A';
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31 | * });
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32 | * const students = [{name: 'Abby', score: 84},
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33 | * {name: 'Eddy', score: 58},
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34 | * // ...
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35 | * {name: 'Jack', score: 69}];
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36 | * byGrade(students);
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37 | * // {
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38 | * // 'A': [{name: 'Dianne', score: 99}],
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39 | * // 'B': [{name: 'Abby', score: 84}]
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40 | * // // ...,
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41 | * // 'F': [{name: 'Eddy', score: 58}]
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42 | * // }
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43 | */
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44 |
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45 | var groupBy =
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46 | /*#__PURE__*/
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47 | _curry2(
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48 | /*#__PURE__*/
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49 | _checkForMethod('groupBy',
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50 | /*#__PURE__*/
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51 | reduceBy(function (acc, item) {
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52 | if (acc == null) {
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53 | acc = [];
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54 | }
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55 |
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56 | acc.push(item);
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57 | return acc;
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58 | }, null)));
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59 |
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60 | export default groupBy; |
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