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import _reduce from './internal/_reduce.js';import _xwrap from './internal/_xwrap.js';import curryN from './curryN.js';

/** * Initializes a transducer using supplied iterator function. Returns a single * item by iterating through the list, successively calling the transformed * iterator function and passing it an accumulator value and the current value * from the array, and then passing the result to the next call. * * The iterator function receives two values: *(acc, value)*. It will be * wrapped as a transformer to initialize the transducer. A transformer can be * passed directly in place of an iterator function. In both cases, iteration * may be stopped early with the [`R.reduced`](#reduced) function. * * A transducer is a function that accepts a transformer and returns a * transformer and can be composed directly. * * A transformer is an object that provides a 2-arity reducing iterator * function, step, 0-arity initial value function, init, and 1-arity result * extraction function, result. The step function is used as the iterator * function in reduce. The result function is used to convert the final * accumulator into the return type and in most cases is * [`R.identity`](#identity). The init function can be used to provide an * initial accumulator, but is ignored by transduce. * * The iteration is performed with [`R.reduce`](#reduce) after initializing the transducer. * * @func * @memberOf R * @since v0.12.0 * @category List * @sig (c -> c) -> ((a, b) -> a) -> a -> [b] -> a * @param {Function} xf The transducer function. Receives a transformer and returns a transformer. * @param {Function} fn The iterator function. Receives two values, the accumulator and the *        current element from the array. Wrapped as transformer, if necessary, and used to *        initialize the transducer * @param {*} acc The initial accumulator value. * @param {Array} list The list to iterate over. * @return {*} The final, accumulated value. * @see R.reduce, R.reduced, R.into * @example * *      const numbers = [1, 2, 3, 4]; *      const transducer = R.compose(R.map(R.add(1)), R.take(2)); *      R.transduce(transducer, R.flip(R.append), [], numbers); //=> [2, 3] * *      const isOdd = (x) => x % 2 === 1; *      const firstOddTransducer = R.compose(R.filter(isOdd), R.take(1)); *      R.transduce(firstOddTransducer, R.flip(R.append), [], R.range(0, 100)); //=> [1] */var transduce = curryN(4, function transduce(xf, fn, acc, list) {  return _reduce(xf(typeof fn === 'function' ? _xwrap(fn) : fn), acc, list);});export default transduce;