1 | import { traverse, curry, pipe, prop, curryN } from 'ramda';
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2 | import Identity from './fantasy-land/Identity';
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3 |
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4 | /**
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5 | * Creates a [Traversable](https://github.com/fantasyland/fantasy-land#traversable) lens
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6 | * from an [Applicative](https://github.com/fantasyland/fantasy-land#applicative)-returning function.
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7 | *
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8 | * When executed, it maps an [Applicative](https://github.com/fantasyland/fantasy-land#applicative)-returning
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9 | * function over a [Traversable](https://github.com/fantasyland/fantasy-land#traversable),
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10 | * then uses [`sequence`](https://ramdajs.com/docs/#sequence) to transform the resulting Traversable of Applicative
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11 | * into an Applicative of Traversable.
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12 | *
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13 | * Dispatches to the `traverse` method of the third argument, if present.
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14 | *
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15 | * @func lensTraverse
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16 | * @memberOf RA
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17 | * @since {@link https://char0n.github.io/ramda-adjunct/2.7.0|2.7.0}
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18 | * @category Relation
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19 | * @typedef Lens s a = Functor f => (a -> f a) -> s -> f s
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20 | * @sig fantasy-land/of :: TypeRep f => f ~> a → f a
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21 | * @sig Applicative f => (a -> f a) -> Lens s a
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22 | * @sig Applicative f => TypeRep f -> Lens s a
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23 | * @param {!Object|!Function} TypeRepresentative with an `of` or `fantasy-land/of` method
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24 | * @return {!function} The Traversable lens
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25 | * @see {@link http://ramdajs.com/docs/#lens|R.lens}, {@link http://ramdajs.com/docs/#traverse|R.traverse}
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26 | *
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27 | * @example
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28 | *
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29 | * const maybeLens = RA.lensTraverse(Maybe.of);
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30 | * const safeDiv = n => d => d === 0 ? Maybe.Nothing() : Maybe.Just(n / d)
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31 | *
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32 | * R.over(maybeLens, safeDiv(10), [2, 4, 5]); // => Just([5, 2.5, 2])
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33 | * R.over(maybeLens, safeDiv(10), [2, 0, 5]); // => Nothing
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34 | *
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35 | * R.view(maybeLens, [Maybe.Just(2), Maybe.Just(3)]); // => Maybe.Just([2, 3])
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36 | *
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37 | * R.set(maybeLens, Maybe.Just(1), [Maybe.just(2), Maybe.Just(3)]); // => Maybe.Just([1, 1])
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38 | */
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39 | /* eslint-disable no-nested-ternary */
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40 | var lensTraverse = curryN(1, function (F) {
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41 | var of = typeof F['fantasy-land/of'] === 'function' ? F['fantasy-land/of'] : typeof F.of === 'function' ? F.of : F;
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42 | var TypeRep = {
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43 | 'fantasy-land/of': of
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44 | };
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45 | return curry(function (toFunctorFn, target) {
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46 | return Identity.of(traverse(TypeRep, pipe(toFunctorFn, prop('value')), target));
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47 | });
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48 | });
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49 | /* eslint-enable */
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50 |
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51 | export default lensTraverse; |
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