text: /**
  * @license Apache-2.0
  *
  * Copyright (c) 2020 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 tape = require( 'tape' );
  var randu = require( '@stdlib/random/iter/randu' );
  var pow = require( '@stdlib/math/base/special/pow' );
  var linspace = require( '@stdlib/iter/linspace' );
  var iterPow = require( './../lib' );
  
  
  // FUNCTIONS //
  
  function createIterator( arr ) {
  	var len;
  	var it;
  	var i;
  
  	len = arr.length;
  	i = -1;
  
  	it = {};
  	it.next = next;
  
  	return it;
  
  	function next() {
  		var out;
  		i += 1;
  		if ( i < len ) {
  			out = {};
  			out.value = arr[ i ];
  			out.done = ( i === len-1 );
  			return out;
  		}
  		return {
  			'done': true
  		};
  	}
  }
  
  
  // TESTS //
  
  tape( 'main export is a function', function test( t ) {
  	t.ok( true, __filename );
  	t.equal( typeof iterPow, 'function', 'main export is a function' );
  	t.end();
  });
  
  tape( 'the function throws an error if provided a first argument which is not an iterator protocol-compliant object or number', function test( t ) {
  	var values;
  	var i;
  
  	values = [
  		'5',
  		true,
  		false,
  		null,
  		void 0,
  		{},
  		[],
  		function noop() {}
  	];
  
  	for ( i = 0; i < values.length; i++ ) {
  		t.throws( badValue( values[i] ), TypeError, 'throws an error when provided '+values[i] );
  	}
  	t.end();
  
  	function badValue( value ) {
  		return function badValue() {
  			iterPow( value, randu() );
  		};
  	}
  });
  
  tape( 'the function throws an error if provided a second argument which is not an iterator protocol-compliant object or number', function test( t ) {
  	var values;
  	var i;
  
  	values = [
  		'5',
  		true,
  		false,
  		null,
  		void 0,
  		{},
  		[],
  		function noop() {}
  	];
  
  	for ( i = 0; i < values.length; i++ ) {
  		t.throws( badValue( values[i] ), TypeError, 'throws an error when provided '+values[i] );
  	}
  	t.end();
  
  	function badValue( value ) {
  		return function badValue() {
  			iterPow( randu(), value );
  		};
  	}
  });
  
  tape( 'the function returns an iterator protocol-compliant object (iterator, iterator)', function test( t ) {
  	var it;
  	var r;
  	var i;
  
  	it = iterPow( randu(), randu() );
  	t.equal( it.next.length, 0, 'has zero arity' );
  
  	for ( i = 0; i < 100; i++ ) {
  		r = it.next();
  		t.equal( typeof r.value, 'number', 'returns a number' );
  		t.equal( typeof r.done, 'boolean', 'returns a boolean' );
  	}
  	t.end();
  });
  
  tape( 'the function returns an iterator protocol-compliant object (iterator, scalar)', function test( t ) {
  	var it;
  	var r;
  	var i;
  
  	it = iterPow( randu(), 2.0 );
  	t.equal( it.next.length, 0, 'has zero arity' );
  
  	for ( i = 0; i < 100; i++ ) {
  		r = it.next();
  		t.equal( typeof r.value, 'number', 'returns a number' );
  		t.equal( typeof r.done, 'boolean', 'returns a boolean' );
  	}
  	t.end();
  });
  
  tape( 'the function returns an iterator protocol-compliant object (scalar, iterator)', function test( t ) {
  	var it;
  	var r;
  	var i;
  
  	it = iterPow( 2.0, randu() );
  	t.equal( it.next.length, 0, 'has zero arity' );
  
  	for ( i = 0; i < 100; i++ ) {
  		r = it.next();
  		t.equal( typeof r.value, 'number', 'returns a number' );
  		t.equal( typeof r.done, 'boolean', 'returns a boolean' );
  	}
  	t.end();
  });
  
  tape( 'the function returns an iterator protocol-compliant object (scalar, scalar)', function test( t ) {
  	var it;
  	var r;
  	var i;
  
  	it = iterPow( 2.0, 2.0 );
  	t.equal( it.next.length, 0, 'has zero arity' );
  
  	for ( i = 0; i < 100; i++ ) {
  		r = it.next();
  		t.equal( typeof r.value, 'number', 'returns a number' );
  		t.equal( typeof r.done, 'boolean', 'returns a boolean' );
  	}
  	t.end();
  });
  
  tape( 'the function returns an iterator protocol-compliant object (value+done; iterator, iterator)', function test( t ) {
  	var values;
  	var it;
  	var r;
  	var i;
  
  	values = [ 0.0, 0.5, 1.0 ];
  	it = iterPow( createIterator( values ), randu() );
  	t.equal( it.next.length, 0, 'has zero arity' );
  
  	for ( i = 0; i < values.length; i++ ) {
  		r = it.next();
  		t.equal( typeof r.value, 'number', 'returns a number' );
  		t.equal( typeof r.done, 'boolean', 'returns a boolean' );
  	}
  	t.end();
  });
  
  tape( 'the function returns an iterator protocol-compliant object (value+done; iterator, scalar)', function test( t ) {
  	var values;
  	var it;
  	var r;
  	var i;
  
  	values = [ 0.0, 0.5, 1.0 ];
  	it = iterPow( createIterator( values ), 2.0 );
  	t.equal( it.next.length, 0, 'has zero arity' );
  
  	for ( i = 0; i < values.length; i++ ) {
  		r = it.next();
  		t.equal( typeof r.value, 'number', 'returns a number' );
  		t.equal( typeof r.done, 'boolean', 'returns a boolean' );
  	}
  	t.end();
  });
  
  tape( 'the function returns an iterator protocol-compliant object (value+done; scalar, iterator)', function test( t ) {
  	var values;
  	var it;
  	var r;
  	var i;
  
  	values = [ 0.0, 0.5, 1.0 ];
  	it = iterPow( 2.0, createIterator( values ) );
  	t.equal( it.next.length, 0, 'has zero arity' );
  
  	for ( i = 0; i < values.length; i++ ) {
  		r = it.next();
  		t.equal( typeof r.value, 'number', 'returns a number' );
  		t.equal( typeof r.done, 'boolean', 'returns a boolean' );
  	}
  	t.end();
  });
  
  tape( 'the function returns an iterator protocol-compliant object which evaluates the exponential function for each iterated value (iterator, iterator)', function test( t ) {
  	var expected;
  	var it;
  	var N;
  	var x;
  	var y;
  	var r;
  	var i;
  
  	N = 101;
  	it = iterPow( linspace( 0.0, 2.0, N ), linspace( -3.14, 3.14, N ) );
  	t.equal( it.next.length, 0, 'has zero arity' );
  
  	x = linspace( 0.0, 2.0, N );
  	y = linspace( -3.14, 3.14, N );
  	for ( i = 0; i < N; i++ ) {
  		r = it.next();
  		expected = pow( x.next().value, y.next().value );
  		t.equal( r.value, expected, 'returns expected value' );
  		t.equal( typeof r.done, 'boolean', 'returns a boolean' );
  	}
  	r = it.next();
  	t.equal( r.value, void 0, 'returns expected value' );
  	t.equal( r.done, true, 'returns expected value' );
  
  	t.end();
  });
  
  tape( 'the function returns an iterator protocol-compliant object which evaluates the exponential function for each iterated value (iterator, scalar)', function test( t ) {
  	var expected;
  	var it;
  	var N;
  	var x;
  	var r;
  	var i;
  
  	N = 101;
  	it = iterPow( linspace( -3.14, 3.14, N ), 2.0 );
  	t.equal( it.next.length, 0, 'has zero arity' );
  
  	x = linspace( -3.14, 3.14, N );
  	for ( i = 0; i < N; i++ ) {
  		r = it.next();
  		expected = pow( x.next().value, 2.0 );
  		t.equal( r.value, expected, 'returns expected value' );
  		t.equal( typeof r.done, 'boolean', 'returns a boolean' );
  	}
  	r = it.next();
  	t.equal( r.value, void 0, 'returns expected value' );
  	t.equal( r.done, true, 'returns expected value' );
  
  	t.end();
  });
  
  tape( 'the function returns an iterator protocol-compliant object which evaluates the exponential function for each iterated value (scalar, iterator)', function test( t ) {
  	var expected;
  	var it;
  	var N;
  	var y;
  	var r;
  	var i;
  
  	N = 101;
  	it = iterPow( 2.0, linspace( -2.0, 2.0, N ) );
  	t.equal( it.next.length, 0, 'has zero arity' );
  
  	y = linspace( -2.0, 2.0, N );
  	for ( i = 0; i < N; i++ ) {
  		r = it.next();
  		expected = pow( 2.0, y.next().value );
  		t.equal( r.value, expected, 'returns expected value' );
  		t.equal( typeof r.done, 'boolean', 'returns a boolean' );
  	}
  	r = it.next();
  	t.equal( r.value, void 0, 'returns expected value' );
  	t.equal( r.done, true, 'returns expected value' );
  
  	t.end();
  });
  
  tape( 'the function returns an iterator protocol-compliant object which evaluates the exponential function for each iterated value (scalar, scalar)', function test( t ) {
  	var expected;
  	var actual;
  	var it;
  	var i;
  
  	it = iterPow( 2.0, 2.0 );
  	t.equal( it.next.length, 0, 'has zero arity' );
  
  	expected = {
  		'value': pow( 2.0, 2.0 ),
  		'done': false
  	};
  	for ( i = 0; i < 100; i++ ) {
  		actual = it.next();
  		t.deepEqual( actual, expected, 'returns expected value' );
  	}
  	t.end();
  });
  
  tape( 'the function returns an iterator protocol-compliant object which evaluates the exponential function for each iterated value (value+done; iterator, iterator)', function test( t ) {
  	var expected;
  	var actual;
  	var it;
  	var x;
  	var y;
  	var i;
  
  	x = [ 1.0, 0.5, 0.0, 0.5 ];
  	y = [ -1.0, -0.5, 0.0, 0.5 ];
  	expected = [
  		{
  			'value': pow( x[ 0 ], y[ 0 ] ),
  			'done': false
  		},
  		{
  			'value': pow( x[ 1 ], y[ 1 ] ),
  			'done': false
  		},
  		{
  			'value': pow( x[ 2 ], y[ 2 ] ),
  			'done': false
  		},
  		{
  			'value': pow( x[ 3 ], y[ 3 ] ),
  			'done': false
  		},
  		{
  			'done': true
  		}
  	];
  
  	it = iterPow( createIterator( x ), createIterator( y ) );
  	t.equal( it.next.length, 0, 'has zero arity' );
  
  	for ( i = 0; i < expected.length; i++ ) {
  		actual = it.next();
  		t.deepEqual( actual, expected[ i ], 'returns expected value' );
  	}
  	t.end();
  });
  
  tape( 'the function returns an iterator protocol-compliant object which evaluates the exponential function for each iterated value (value+done; iterator, scalar)', function test( t ) {
  	var expected;
  	var actual;
  	var it;
  	var x;
  	var i;
  
  	x = [ -1.0, -0.5, 0.0, 0.5 ];
  	expected = [
  		{
  			'value': pow( x[ 0 ], 2.0 ),
  			'done': false
  		},
  		{
  			'value': pow( x[ 1 ], 2.0 ),
  			'done': false
  		},
  		{
  			'value': pow( x[ 2 ], 2.0 ),
  			'done': false
  		},
  		{
  			'value': pow( x[ 3 ], 2.0 ),
  			'done': false
  		},
  		{
  			'done': true
  		}
  	];
  
  	it = iterPow( createIterator( x ), 2.0 );
  	t.equal( it.next.length, 0, 'has zero arity' );
  
  	for ( i = 0; i < expected.length; i++ ) {
  		actual = it.next();
  		t.deepEqual( actual, expected[ i ], 'returns expected value' );
  	}
  	t.end();
  });
  
  tape( 'the function returns an iterator protocol-compliant object which evaluates the exponential function for each iterated value (value+done; scalar, iterator)', function test( t ) {
  	var expected;
  	var actual;
  	var it;
  	var y;
  	var i;
  
  	y = [ 1.0, 0.5, 0.0, -0.5 ];
  	expected = [
  		{
  			'value': pow( 2.0, y[ 0 ] ),
  			'done': false
  		},
  		{
  			'value': pow( 2.0, y[ 1 ] ),
  			'done': false
  		},
  		{
  			'value': pow( 2.0, y[ 2 ] ),
  			'done': false
  		},
  		{
  			'value': pow( 2.0, y[ 3 ] ),
  			'done': false
  		},
  		{
  			'done': true
  		}
  	];
  
  	it = iterPow( 2.0, createIterator( y ) );
  	t.equal( it.next.length, 0, 'has zero arity' );
  
  	for ( i = 0; i < expected.length; i++ ) {
  		actual = it.next();
  		t.deepEqual( actual, expected[ i ], 'returns expected value' );
  	}
  	t.end();
  });
  
  tape( 'the function returns an iterator protocol-compliant object which evaluates the exponential function for each iterated value (value+done; scalar, scalar)', function test( t ) {
  	var expected;
  	var actual;
  	var it;
  	var i;
  
  	it = iterPow( 2.0, 2.0 );
  	t.equal( it.next.length, 0, 'has zero arity' );
  
  	expected = {
  		'value': pow( 2.0, 2.0 ),
  		'done': false
  	};
  	for ( i = 0; i < 100; i++ ) {
  		actual = it.next();
  		t.deepEqual( actual, expected, 'returns expected value' );
  	}
  	t.end();
  });
  
  tape( 'the function returns an iterator protocol-compliant object which returns `NaN` if provided a non-numeric value (value+done)', function test( t ) {
  	var expected;
  	var values;
  	var actual;
  	var it;
  	var r;
  	var i;
  
  	values = [ 'abc', null, true, false, [], {} ];
  	expected = [
  		{
  			'value': NaN,
  			'done': false
  		},
  		{
  			'value': NaN,
  			'done': false
  		},
  		{
  			'value': NaN,
  			'done': false
  		},
  		{
  			'value': NaN,
  			'done': false
  		},
  		{
  			'value': NaN,
  			'done': false
  		},
  		{
  			'value': NaN,
  			'done': false
  		},
  		{
  			'done': true
  		}
  	];
  
  	it = iterPow( createIterator( values ), randu() );
  	t.equal( it.next.length, 0, 'has zero arity' );
  
  	for ( i = 0; i < expected.length; i++ ) {
  		actual = it.next();
  		r = expected[ i ].value;
  		if ( r === r ) {
  			t.equal( actual.value, r, 'returns expected value' );
  		} else {
  			t.notEqual( actual.value, actual.value, 'returns expected value' );
  		}
  		t.equal( actual.done, expected[ i ].done, 'returns a boolean' );
  	}
  	t.end();
  });
  
  tape( 'the returned iterator has a `return` method for closing an iterator (no argument)', function test( t ) {
  	var it;
  	var r;
  
  	it = iterPow( randu(), randu() );
  
  	r = it.next();
  	t.equal( typeof r.value, 'number', 'returns a number' );
  	t.equal( r.done, false, 'returns expected value' );
  
  	r = it.next();
  	t.equal( typeof r.value, 'number', 'returns a number' );
  	t.equal( r.done, false, 'returns expected value' );
  
  	r = it.return();
  	t.equal( r.value, void 0, 'returns expected value' );
  	t.equal( r.done, true, 'returns expected value' );
  
  	r = it.next();
  	t.equal( r.value, void 0, 'returns expected value' );
  	t.equal( r.done, true, 'returns expected value' );
  
  	t.end();
  });
  
  tape( 'the returned iterator has a `return` method for closing an iterator (argument)', function test( t ) {
  	var it;
  	var r;
  
  	it = iterPow( randu(), randu() );
  
  	r = it.next();
  	t.equal( typeof r.value, 'number', 'returns a number' );
  	t.equal( r.done, false, 'returns expected value' );
  
  	r = it.next();
  	t.equal( typeof r.value, 'number', 'returns a number' );
  	t.equal( r.done, false, 'returns expected value' );
  
  	r = it.return( 'finished' );
  	t.equal( r.value, 'finished', 'returns expected value' );
  	t.equal( r.done, true, 'returns expected value' );
  
  	r = it.next();
  	t.equal( r.value, void 0, 'returns expected value' );
  	t.equal( r.done, true, 'returns expected value' );
  
  	t.end();
  });
  