text: /**
  * @license Apache-2.0
  *
  * Copyright (c) 2018 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 setReadOnlyAccessor = require( '@stdlib/utils/define-nonenumerable-read-only-accessor' );
  var setReadWriteAccessor = require( '@stdlib/utils/define-nonenumerable-read-write-accessor' );
  var constantFunction = require( '@stdlib/utils/constant-function' );
  var noop = require( '@stdlib/utils/noop' );
  var copy = require( '@stdlib/utils/copy' );
  var isProbability = require( '@stdlib/assert/is-probability' ).isPrimitive;
  var isObject = require( '@stdlib/assert/is-plain-object' );
  var isNonNegativeInteger = require( '@stdlib/assert/is-nonnegative-integer' ).isPrimitive;
  var hasOwnProp = require( '@stdlib/assert/has-own-property' );
  var MAX_VALUE = require( '@stdlib/constants/math/float64-max' );
  var rgeom = require( '@stdlib/random/base/geometric' ).factory;
  var iteratorSymbol = require( '@stdlib/symbol/iterator' );
  
  
  // MAIN //
  
  /**
  * Returns an iterator for generating pseudorandom numbers drawn from a geometric distribution.
  *
  * @param {Probability} p - success probability
  * @param {Options} [options] - function options
  * @param {PRNG} [options.prng] - pseudorandom number generator which generates uniformly distributed pseudorandom numbers
  * @param {PRNGSeedMT19937} [options.seed] - pseudorandom number generator seed
  * @param {PRNGStateMT19937} [options.state] - pseudorandom number generator state
  * @param {boolean} [options.copy=true] - boolean indicating whether to copy a provided pseudorandom number generator state
  * @param {NonNegativeInteger} [options.iter] - number of iterations
  * @throws {TypeError} first argument must be a probability
  * @throws {TypeError} options argument must be an object
  * @throws {TypeError} must provide valid options
  * @throws {Error} must provide a valid state
  * @returns {Iterator} iterator
  *
  * @example
  * var iter = iterator( 0.3 );
  *
  * var r = iter.next().value;
  * // returns <number>
  *
  * r = iter.next().value;
  * // returns <number>
  *
  * r = iter.next().value;
  * // returns <number>
  *
  * // ...
  */
  function iterator( p, options ) {
  	var opts;
  	var iter;
  	var rand;
  	var FLG;
  	var i;
  	if ( !isProbability( p ) ) {
  		throw new TypeError( 'invalid argument. First argument must be a probability. Value: `'+p+'`.' );
  	}
  	if ( arguments.length > 1 ) {
  		if ( !isObject( options ) ) {
  			throw new TypeError( 'invalid argument. Options argument must be an object. Value: `'+options+'`.' );
  		}
  		opts = copy( options, 1 );
  		if ( hasOwnProp( opts, 'iter' ) ) {
  			if ( !isNonNegativeInteger( opts.iter ) ) {
  				throw new TypeError( 'invalid option. `iter` option must be a nonnegative integer. Option: `'+opts.iter+'`.' );
  			}
  		} else {
  			opts.iter = MAX_VALUE;
  		}
  		rand = rgeom( p, opts );
  		if ( opts.prng === void 0 && opts.copy !== false ) {
  			opts.state = rand.state; // cache a copy of the PRNG state
  		}
  	} else {
  		rand = rgeom( p );
  		opts = {
  			'iter': MAX_VALUE,
  			'state': rand.state // cache a copy of the PRNG state
  		};
  	}
  	i = 0;
  
  	// Create an iterator protocol-compliant object:
  	iter = {};
  	setReadOnly( iter, 'next', next );
  	setReadOnly( iter, 'return', end );
  
  	if ( opts && opts.prng ) {
  		setReadOnly( iter, 'seed', null );
  		setReadOnly( iter, 'seedLength', null );
  		setReadWriteAccessor( iter, 'state', constantFunction( null ), noop );
  		setReadOnly( iter, 'stateLength', null );
  		setReadOnly( iter, 'byteLength', null );
  	} else {
  		setReadOnlyAccessor( iter, 'seed', getSeed );
  		setReadOnlyAccessor( iter, 'seedLength', getSeedLength );
  		setReadWriteAccessor( iter, 'state', getState, setState );
  		setReadOnlyAccessor( iter, 'stateLength', getStateLength );
  		setReadOnlyAccessor( iter, 'byteLength', getStateSize );
  	}
  	setReadOnly( iter, 'PRNG', rand.PRNG );
  
  	// If an environment supports `Symbol.iterator`, make the iterator iterable:
  	if ( iteratorSymbol ) {
  		setReadOnly( iter, iteratorSymbol, factory );
  	}
  	return iter;
  
  	/**
  	* Returns an iterator protocol-compliant object containing the next iterated value.
  	*
  	* @private
  	* @returns {Object} iterator protocol-compliant object
  	*/
  	function next() {
  		i += 1;
  		if ( FLG || i > opts.iter ) {
  			return {
  				'done': true
  			};
  		}
  		return {
  			'value': rand(),
  			'done': false
  		};
  	}
  
  	/**
  	* Finishes an iterator.
  	*
  	* @private
  	* @param {*} [value] - value to return
  	* @returns {Object} iterator protocol-compliant object
  	*/
  	function end( value ) {
  		FLG = true;
  		if ( arguments.length ) {
  			return {
  				'value': value,
  				'done': true
  			};
  		}
  		return {
  			'done': true
  		};
  	}
  
  	/**
  	* Returns a new iterator.
  	*
  	* @private
  	* @returns {Iterator} iterator
  	*/
  	function factory() {
  		return iterator( p, opts );
  	}
  
  	/**
  	* Returns the PRNG seed.
  	*
  	* @private
  	* @returns {PRNGSeedMT19937} seed
  	*/
  	function getSeed() {
  		return rand.PRNG.seed;
  	}
  
  	/**
  	* Returns the PRNG seed length.
  	*
  	* @private
  	* @returns {PositiveInteger} seed length
  	*/
  	function getSeedLength() {
  		return rand.PRNG.seedLength;
  	}
  
  	/**
  	* Returns the PRNG state length.
  	*
  	* @private
  	* @returns {PositiveInteger} state length
  	*/
  	function getStateLength() {
  		return rand.PRNG.stateLength;
  	}
  
  	/**
  	* Returns the PRNG state size (in bytes).
  	*
  	* @private
  	* @returns {PositiveInteger} state size (in bytes)
  	*/
  	function getStateSize() {
  		return rand.PRNG.byteLength;
  	}
  
  	/**
  	* Returns the current pseudorandom number generator state.
  	*
  	* @private
  	* @returns {PRNGStateMT19937} current state
  	*/
  	function getState() {
  		return rand.PRNG.state;
  	}
  
  	/**
  	* Sets the pseudorandom number generator state.
  	*
  	* @private
  	* @param {PRNGStateMT19937} s - generator state
  	* @throws {Error} must provide a valid state
  	*/
  	function setState( s ) {
  		rand.PRNG.state = s;
  	}
  }
  
  
  // EXPORTS //
  
  module.exports = iterator;
  