text: /**
  * @license Apache-2.0
  *
  * Copyright (c) 2019 The Stdlib Authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *    http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
  
  'use strict';
  
  // MODULES //
  
  var setReadOnly = require( '@stdlib/utils/define-nonenumerable-read-only-property' );
  var isFunction = require( '@stdlib/assert/is-function' );
  var isIteratorLike = require( '@stdlib/assert/is-iterator-like' );
  var hasOwnProp = require( '@stdlib/assert/has-own-property' );
  var iteratorSymbol = require( '@stdlib/symbol/iterator' );
  
  
  // MAIN //
  
  /**
  * Returns an iterator which transforms iterated values from two or more iterators by applying the iterated values as arguments to a provided function.
  *
  * @param {Iterator} iter0 - first input iterator
  * @param {...Iterator} iterator - subsequent iterators
  * @param {Function} fcn - function to invoke
  * @param {*} [thisArg] - execution context
  * @throws {Error} must provide two or more iterators
  * @throws {TypeError} must provide iterator protocol-compliant objects
  * @throws {TypeError} callback argument must be a function
  * @returns {Iterator} iterator
  *
  * @example
  * var array2iterator = require( '@stdlib/array/to-iterator' );
  *
  * function transform( x, y ) {
  *     return x + y;
  * }
  *
  * var it1 = array2iterator( [ 1.0, 2.0 ] );
  * var it2 = array2iterator( [ 3.0, 4.0 ] );
  *
  * var iter = iterMapN( it1, it2, transform );
  *
  * var v = iter.next().value;
  * // returns 4.0
  *
  * v = iter.next().value;
  * // returns 6.0
  *
  * var bool = iter.next().done;
  * // returns true
  */
  function iterMapN() {
  	var iterators;
  	var thisArg;
  	var niter;
  	var clbk;
  	var iter;
  	var FLG;
  	var idx;
  	var i;
  
  	niter = arguments.length;
  	if ( !isFunction( arguments[ niter-1 ] ) ) {
  		niter -= 1;
  		thisArg = arguments[ niter ];
  	}
  	niter -= 1;
  	clbk = arguments[ niter ];
  	if ( !isFunction( clbk ) ) {
  		throw new TypeError( 'invalid argument. Callback argument must be a function. Value: `' + clbk + '`.' );
  	}
  	if ( niter < 2 ) {
  		throw new Error( 'insufficient input arguments. Must provide two or more iterators.' );
  	}
  	iterators = [];
  	for ( i = 0; i < niter; i++ ) {
  		if ( !isIteratorLike( arguments[ i ] ) ) {
  			throw new TypeError( 'invalid argument. Must provide an iterator protocol-compliant object. Argument: `' + i + '`. Value: `' + arguments[ i ] + '`.' );
  		}
  		iterators.push( arguments[ i ] );
  	}
  	// Create an iterator protocol-compliant object:
  	iter = {};
  	setReadOnly( iter, 'next', next );
  	setReadOnly( iter, 'return', end );
  
  	// If an environment supports `Symbol.iterator` and all provided iterators are iterable, make the iterator iterable:
  	if ( iteratorSymbol ) {
  		for ( i = 0; i < niter; i++ ) {
  			if ( !isFunction( iterators[ i ][ iteratorSymbol ] ) ) {
  				FLG = true;
  				break;
  			}
  		}
  		if ( !FLG ) {
  			setReadOnly( iter, iteratorSymbol, factory );
  		}
  	}
  	idx = -1;
  	FLG = 0;
  	i = 0;
  	return iter;
  
  	/**
  	* Returns an iterator protocol-compliant object containing the next iterated value.
  	*
  	* @private
  	* @returns {Object} iterator protocol-compliant object
  	*/
  	function next() {
  		var args;
  		var v;
  		var i;
  		if ( FLG ) {
  			return {
  				'done': true
  			};
  		}
  		args = [];
  		idx += 1;
  		FLG = 0;
  		for ( i = 0; i < niter; i++ ) {
  			v = iterators[ i ].next();
  			if ( v.done ) {
  				FLG += 1;
  				if ( hasOwnProp( v, 'value' ) ) {
  					args.push( v.value );
  					continue;
  				}
  				return {
  					'done': true
  				};
  			}
  			args.push( v.value );
  		}
  		args.push( idx );
  		return {
  			'value': clbk.apply( thisArg, args ),
  			'done': false
  		};
  	}
  
  	/**
  	* Finishes an iterator.
  	*
  	* @private
  	* @param {*} [value] - value to return
  	* @returns {Object} iterator protocol-compliant object
  	*/
  	function end( value ) {
  		FLG = 1;
  		if ( arguments.length ) {
  			return {
  				'value': value,
  				'done': true
  			};
  		}
  		return {
  			'done': true
  		};
  	}
  
  	/**
  	* Returns a new iterator.
  	*
  	* @private
  	* @returns {Iterator} iterator
  	*/
  	function factory() {
  		var args;
  		var i;
  
  		args = [];
  		for ( i = 0; i < niter; i++ ) {
  			args.push( iterators[ i ][ iteratorSymbol ]() );
  		}
  		args.push( clbk );
  		args.push( thisArg );
  		return iterMapN.apply( null, args );
  	}
  }
  
  
  // EXPORTS //
  
  module.exports = iterMapN;
  