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import _arity from './internal/_arity.js';import _curry1 from './internal/_curry1.js';

/** * Accepts a function `fn` and returns a function that guards invocation of * `fn` such that `fn` can only ever be called once, no matter how many times * the returned function is invoked. The first value calculated is returned in * subsequent invocations. * * @func * @memberOf R * @since v0.1.0 * @category Function * @sig (a... -> b) -> (a... -> b) * @param {Function} fn The function to wrap in a call-only-once wrapper. * @return {Function} The wrapped function. * @example * *      const addOneOnce = R.once(x => x + 1); *      addOneOnce(10); //=> 11 *      addOneOnce(addOneOnce(50)); //=> 11 */var once = _curry1(function once(fn) {  var called = false;  var result;  return _arity(fn.length, function() {    if (called) {      return result;    }    called = true;    result = fn.apply(this, arguments);    return result;  });});export default once;