1 | var _arity =
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2 | /*#__PURE__*/
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3 | require("./internal/_arity");
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4 |
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5 | var _curry1 =
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6 | /*#__PURE__*/
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7 | require("./internal/_curry1");
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8 | /**
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9 | * Accepts a function `fn` and returns a function that guards invocation of
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10 | * `fn` such that `fn` can only ever be called once, no matter how many times
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11 | * the returned function is invoked. The first value calculated is returned in
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12 | * subsequent invocations.
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13 | *
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14 | * @func
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15 | * @memberOf R
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16 | * @since v0.1.0
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17 | * @category Function
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18 | * @sig (a... -> b) -> (a... -> b)
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19 | * @param {Function} fn The function to wrap in a call-only-once wrapper.
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20 | * @return {Function} The wrapped function.
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21 | * @example
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22 | *
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23 | * const addOneOnce = R.once(x => x + 1);
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24 | * addOneOnce(10); //=> 11
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25 | * addOneOnce(addOneOnce(50)); //=> 11
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26 | */
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27 |
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28 |
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29 | var once =
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30 | /*#__PURE__*/
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31 | _curry1(function once(fn) {
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32 | var called = false;
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33 | var result;
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34 | return _arity(fn.length, function () {
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35 | if (called) {
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36 | return result;
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37 | }
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38 |
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39 | called = true;
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40 | result = fn.apply(this, arguments);
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41 | return result;
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42 | });
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43 | });
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44 |
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45 | module.exports = once; |
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