README

安装

composer require gielfeldt/iterators

迭代器

这个库包含了一系列各种迭代器，我主要是为了更好地了解PHP中的迭代器而编写的。其中一些可能有用，而另一些可能很愚蠢。

享受吧！

ReservoirSamplingIterator

CachingIterator

缓存迭代器以进行多次迭代。

use Gielfeldt\Iterators\CachingIterator;

$input = new \ArrayIterator(range(1, 4));
$input = new \NoRewindIterator($input);
$cached = new CachingIterator($input);

print_r(iterator_to_array($cached));
print_r(iterator_to_array($cached));

输出

Array
(
    [0] => 1
    [1] => 2
    [2] => 3
    [3] => 4
)
Array
(
    [0] => 1
    [1] => 2
    [2] => 3
    [3] => 4
)

ChecksumIterator

为迭代器生成校验和，可以是每次迭代或整个数据集。

use Gielfeldt\Iterators\ChecksumIterator;

$input = new \ArrayIterator([
    ['key1' => 'value1'],
    ['key2' => 'value2'],
    ['key3' => 'value3'],
]);

$iterator = new ChecksumIterator($input, 'md5');
foreach ($iterator as $key => $value) {
    print "$key => $value\n";
}

var_dump($iterator->getChecksum());

var_dump((string) $iterator);

输出

0 => e2e517365ffe6fedd279364e3fa74786
1 => f0a0db0fc9abe193b21fd657fe678884
2 => c04f606bb5bba82282dfa93edb59c6ee

string(32) "4fd19adc845da6fdd9c7c394f4626bac"

string(32) "4fd19adc845da6fdd9c7c394f4626bac"

ChunkIterator

将迭代器分割成迭代器的块。

use Gielfeldt\Iterators\ChunkIterator;
use Gielfeldt\Iterators\AtomicTempFileObject;

// Split a file into multiple files of a 100 lines each.
$file = new \SplFileObject('inputfile');
foreach (new ChunkIterator($file, 100) as $i => $lines) {
    AtomicTempFileObject::file_put_contents("outputfile.part.$i", implode("", iterator_to_array($lines)));
}

CloningIterator

克隆迭代中的每个值。

use Gielfeldt\Iterators\CloningIterator;

$object1 = (object) ['value' => 'test1'];
$object2 = (object) ['value' => 'test2'];
$object3 = (object) ['value' => 'test3'];

$input = new \ArrayIterator([$object1, $object2, $object3]);

$iterator = new CloningIterator($input);
$cloned = iterator_to_array($iterator);
$object1->value = 'MODIFIED';
var_dump(iterator_to_array($input));
var_dump($cloned);

输出

array(3) {
  [0] =>
  class stdClass#2 (1) {
    public $value =>
    string(8) "MODIFIED"
  }
  [1] =>
  class stdClass#3 (1) {
    public $value =>
    string(5) "test2"
  }
  [2] =>
  class stdClass#4 (1) {
    public $value =>
    string(5) "test3"
  }
}

array(3) {
  [0] =>
  class stdClass#9 (1) {
    public $value =>
    string(5) "test1"
  }
  [1] =>
  class stdClass#10 (1) {
    public $value =>
    string(5) "test2"
  }
  [2] =>
  class stdClass#11 (1) {
    public $value =>
    string(5) "test3"
  }
}

CombineIterator

类似于array_combine()。然而，迭代器可以有非唯一键。在使用iterator_to_array()时请注意这一点；

use Gielfeldt\Iterators\CombineIterator;

$keys = new \ArrayIterator(['key1', 'key2', 'key3', 'key1', 'key2', 'key3']);
$values = new \ArrayIterator(['value1', 'value2', 'value3', 'value4', 'value5', 'value6']);

$iterator = new CombineIterator($keys, $values);
foreach ($iterator as $key => $value) {
    print "$key => $value\n";
}

print_r(iterator_to_array($iterator));

输出

key1 => value1
key2 => value2
key3 => value3
key1 => value4
key2 => value5
key3 => value6
Array
(
    [key1] => value4
    [key2] => value5
    [key3] => value6
)

CountableIterator

通过迭代并计数使其可计数的任何迭代器。

use Gielfeldt\Iterators\CountableIterator;

$some_noncountable_iterator = new \IteratorIterator(new \ArrayIterator([1, 2, 3]));
$iterator = new CountableIterator($some_noncountable_iterator);
var_dump(count($iterator));

输出

int(3)

DiffIterator

比较两个迭代器。类似于array_diff()。可以设置自定义比较函数。

use Gielfeldt\Iterators\DiffIterator;

$input1 = new \ArrayIterator(['key1'  => 'value1', 'key2'  => 'value2', 'key3'  => 'value3']);
$input2 = new \ArrayIterator(['key11' => 'value1', 'key22' => 'value1', 'key2'  => 'value3']);
$input3 = new \ArrayIterator(['key1'  => 'value2', 'key2'  => 'value2', 'key33' => 'value3']);

$iterator = new DiffIterator($input1, $input2, $input3);
$iterator->setDiff(function ($iterator, $key, $value) {
    return $iterator->key() == $key && $iterator->current() == $value;
});
print_r(iterator_to_array($iterator));

输出

Array
(
    [key1] => value1
    [key3] => value3
)

FiniteIterator

通过匿名函数为迭代器提供一个结束条件。

use Gielfeldt\Iterators\FiniteIterator;

$input = new \ArrayIterator(range(1, 8));
$some = new FiniteIterator($input, function ($iterator) {
    return $iterator->current() > 5;
});

print_r(iterator_to_array($some));

输出

Array
(
    [0] => 1
    [1] => 2
    [2] => 3
    [3] => 4
    [4] => 5
)

FlipIterator

类似于array_flip()。然而，迭代器可以有非唯一键。在使用iterator_to_array()时请注意这一点；

use Gielfeldt\Iterators\FlipIterator;

$input = new \ArrayIterator([
    'key1'  => 'value1',
    'key2'  => 'value2',
    'key3'  => 'value3',
    'key4'  => 'value1',
    'key5'  => 'value2',
    'key6'  => 'value3',
]);

$iterator = new FlipIterator($input);
foreach ($iterator as $key => $value) {
    print "$key => $value\n";
}

print_r(iterator_to_array($iterator));

输出

value1 => key1
value2 => key2
value3 => key3
value1 => key4
value2 => key5
value3 => key6
Array
(
    [value1] => key4
    [value2] => key5
    [value3] => key6
)

GlobIterator

类似于\GlobIterator，但支持**

use Gielfeldt\Iterators\GlobIterator;

$iterator = new GlobIterator('/tmp/**.log');
var_dump(iterator_to_array($iterator));

输出

array(2) {
  '/tmp/one.log' =>
  class Gielfeldt\Iterators\GlobIteratorFileInfo#17 (2) {
    private $pathName =>
    string(20) "/tmp/one.log"
    private $fileName =>
    string(10) "one.log"
  }
  '/tmp/somedir/two.log' =>
  class Gielfeldt\Iterators\GlobIteratorFileInfo#16 (2) {
    private $pathName =>
    string(20) "/tmp/somedir/two.log"
    private $fileName =>
    string(15) "two.log"
  }
}

IndexIterator

仅遍历迭代器的某些行。

use Gielfeldt\Iterators\IndexIterator;

$input = new \ArrayIterator([
    'test1' => 'val6',
    'test2' => 'val5',
    'test3' => 'val4',
    'test4' => 'val3',
    'test5' => 'val2',
    'test6' => 'val1',
]);
$some = new IndexIterator($input, [2, 3, 5]);

print_r(iterator_to_array($some));

输出

Array
(
    [test3] => val4
    [test4] => val3
    [test6] => val1
)

InfiniteIterator

类似于SPL的InfiniteIterator，但提供了getCurrentIteration()方法。

use Gielfeldt\Iterators\InfiniteIterator;
use Gielfeldt\Iterators\FiniteIterator;

$input = new \ArrayIterator(range(1, 4));
$infinite = new InfiniteIterator($input);
$some = new FiniteIterator($infinite, function ($iterator) {
    return $iterator->getCurrentIteration() >= 2 && $iterator->current() > 2;
});

foreach ($some as $k => $v) {
    print $some->getCurrentIteration() . ": $k => $v\n";
}

输出

0: 0 => 1
0: 1 => 2
0: 2 => 3
0: 3 => 4
1: 0 => 1
1: 1 => 2
1: 2 => 3
1: 3 => 4
2: 0 => 1
2: 1 => 2

InterleaveIterator

交错多个迭代器。

use Gielfeldt\Iterators\InterleaveIterator;

$input1 = new \ArrayIterator([
    'key1' => 'value11',
    'key2' => 'value12',
    'key3' => 'value13',
]);

$input2 = new \ArrayIterator([
    'key21' => 'value21',
    'key22' => 'value22',
    'key23' => 'value23',
]);

$input3 = new \ArrayIterator([
    'key1' => 'value31',
    'key2' => 'value32',
    'key3' => 'value33',
]);

$iterator = new InterleaveIterator($input1, $input2, $input3);
foreach ($iterator as $key => $value) {
    print "$key => $value\n";
}

print_r(iterator_to_array($iterator));

输出

key1 => value11
key21 => value21
key1 => value31
key2 => value12
key22 => value22
key2 => value32
key3 => value13
key23 => value23
key3 => value33
Array
(
    [key1] => value31
    [key21] => value21
    [key2] => value32
    [key22] => value22
    [key3] => value33
    [key23] => value23
)

IntersectIterator

类似于array_intersect()。可以设置自定义比较函数。

use Gielfeldt\Iterators\IntersectIterator;

$input1 = new \ArrayIterator(['key1'  => 'value1', 'key2' => 'value2', 'key3' => 'value3']);
$input2 = new \ArrayIterator(['key11' => 'value1', 'key1' => 'value1', 'key2' => 'value3']);
$input3 = new \ArrayIterator(['key1'  => 'value2', 'key2' => 'value2', 'key1' => 'value1']);

$iterator = new IntersectIterator($input1, $input2, $input3);
$iterator->setDiff(function ($iterator, $key, $value) {
    return $iterator->key() == $key && $iterator->current() == $value;
});
print_r(iterator_to_array($iterator));

输出

Array
(
    [key1] => value1
)

TraversableIterator

类似于SPL的IteratorIterator，但有一个更有意义的名字:-)并提供getIndex()方法。

use Gielfeldt\Iterators\TraversableIterator;

$keys = range(1, 10);
shuffle($keys);
$values = range(1, 10);
shuffle($values);

$input = new \ArrayIterator(array_combine($keys, $values));
$iterator = new TraversableIterator($input);

foreach ($iterator as $k => $v) {
    print $iterator->getIndex() . ": $k => $v\n";
}

输出

0: 1 => 3
1: 4 => 2
2: 9 => 10
3: 3 => 8
4: 2 => 6
5: 5 => 5
6: 8 => 1
7: 10 => 9
8: 6 => 7
9: 7 => 4

KeysIterator

类似于array_keys()。

use Gielfeldt\Iterators\KeysIterator;

$input = new \ArrayIterator([
    'key1' => 'value1',
    'key2' => 'value2',
    'key3' => 'value3',
]);

$iterator = new KeysIterator($input);

print_r(iterator_to_array($iterator));

输出

Array
(
    [0] => key1
    [1] => key2
    [2] => key3
)

MapIterator

类似于array_map()。

use Gielfeldt\Iterators\MapIterator;

$input = new \ArrayIterator([
    'key1'  => 'value1',
    'key2'  => 'value2',
    'key3'  => 'value3',
    'key4'  => 'value1',
    'key5'  => 'value2',
    'key6'  => 'value3',
]);

// Flip keys and values.
$iterator = new MapIterator($input, function ($iterator) {
    return [$iterator->current(), $iterator->key()];
});

foreach ($iterator as $key => $value) {
    print "$key => $value\n";
}

print_r(iterator_to_array($iterator));

输出

value1 => key1
value2 => key2
value3 => key3
value1 => key4
value2 => key5
value3 => key6
Array
(
    [value1] => key4
    [value2] => key5
    [value3] => key6
)

RandomIterator

从可遍历的集合中选择一组随机元素。不适用于只能遍历一次的迭代器。请参阅ReservoirSamplingIterator。

use Gielfeldt\Iterators\RandomIterator;

$input = new \ArrayIterator(range(1, 10));
$random = new RandomIterator($input, 4);

var_dump(count($random));

print_r(iterator_to_array($random));

输出

int(4)
Array
(
    [1] => 2
    [6] => 7
    [7] => 8
    [8] => 9
)

RepeatIterator

重复迭代器n次。

use Gielfeldt\Iterators\RepeatIterator;

$input = new \ArrayIterator([
    'key1'  => 'value1',
    'key2'  => 'value2',
    'key3'  => 'value3',
]);

$iterator = new RepeatIterator($input, 3);

foreach ($iterator as $key => $value) {
    print "$key => $value\n";
}

print_r(iterator_to_array($iterator));

输出

key1 => value1
key2 => value2
key3 => value3
key1 => value1
key2 => value2
key3 => value3
key1 => value1
key2 => value2
key3 => value3
Array
(
    [key1] => value1
    [key2] => value2
    [key3] => value3
)

ReplaceableIterator

类似于TraversableIterator，但具有setInnerIterator()方法。

use Gielfeldt\Iterators\ReplaceableIterator;

$iterator = new ReplaceableIterator(new \ArrayIterator(range(1, 4)));
print_r(iterator_to_array($iterator));

$iterator->setInnerIterator(new \ArrayIterator(range(5, 8)));
print_r(iterator_to_array($iterator));

输出

Array
(
    [0] => 1
    [1] => 2
    [2] => 3
    [3] => 4
)
Array
(
    [0] => 5
    [1] => 6
    [2] => 7
    [3] => 8
)

ReservoirSamplingIterator

类似于RandomIterator，但更有效地处理未知大小或只能遍历一次的迭代器。

use Gielfeldt\Iterators\ReservoirSamplingIterator;

$input = new \ArrayIterator(range(1, 10));
$input = new \NoRewindIterator($input);
$random = new ReservoirSamplingIterator($input, 4);

print_r(iterator_to_array($random));

输出

int(4)
Array
(
    [1] => 2
    [6] => 7
    [7] => 8
    [8] => 9
)

ShuffleIterator

随机遍历可遍历的集合。

use Gielfeldt\Iterators\ShuffleIterator;

$input = new \ArrayIterator(range(1, 10));
$shuffled = new ShuffleIterator($input);

print_r(iterator_to_array($shuffled));
print_r(iterator_to_array($shuffled));

输出

Array
(
    [1] => 2
    [4] => 5
    [0] => 1
    [9] => 10
    [7] => 8
    [5] => 6
    [2] => 3
    [8] => 9
    [3] => 4
    [6] => 7
)
Array
(
    [1] => 2
    [9] => 10
    [4] => 5
    [2] => 3
    [5] => 6
    [0] => 1
    [8] => 9
    [3] => 4
    [7] => 8
    [6] => 7
)

SortIterator

use Gielfeldt\Iterators\SortIterator;

$input = new \ArrayIterator([6, 3, 2, 7, 1, 9]);
$iterator = new SortIterator($input);
print_r(iterator_to_array($iterator));

$input = new \ArrayIterator([6, 3, 2, 7, 1, 9]);
$iterator = new SortIterator($input, SortIterator::SORT_DESC);
print_r(iterator_to_array($iterator));

$input = new \ArrayIterator([6, 3, 2, 7, 1, 9]);
$iterator = new SortIterator($input, SortIterator::SORT_ASC, SortIterator::SORT_REINDEX);
print_r(iterator_to_array($iterator));

$input = new \ArrayIterator([6, 3, 2, 7, 1, 9]);
$iterator = new SortIterator($input, SortIterator::SORT_ASC, SortIterator::SORT_REINDEX, function ($a, $b) {
    return -$a->current <=> -$b->current;
});
print_r(iterator_to_array($iterator));

输出

Array
(
    [4] => 1
    [2] => 2
    [1] => 3
    [0] => 6
    [3] => 7
    [5] => 9
)
Array
(
    [5] => 9
    [3] => 7
    [0] => 6
    [1] => 3
    [2] => 2
    [4] => 1
)
Array
(
    [0] => 1
    [1] => 2
    [2] => 3
    [3] => 6
    [4] => 7
    [5] => 9
)
Array
(
    [0] => 9
    [1] => 7
    [2] => 6
    [3] => 3
    [4] => 2
    [5] => 1
)

StepIterator

以步长遍历可遍历的集合。

use Gielfeldt\Iterators\StepIterator;

$input = new \ArrayIterator(range(1, 10));
$stepped = new StepIterator($input, 2);

print_r(iterator_to_array($stepped));

输出

Array
(
    [0] => 1
    [2] => 3
    [4] => 5
    [6] => 7
    [8] => 9
)

UniqueIterator

类似于array_unique()。也支持自定义回调函数。

use Gielfeldt\Iterators\UniqueIterator;

$input = new \ArrayIterator([-4, -3, -2, -1, 0, 1, 2, 3, 5]);

// Unique elements by their square.
$iterator = new UniqueIterator($input, UniqueIterator::REINDEX, function ($iterator) {
    return $iterator->current() * $iterator->current();
});

print_r(iterator_to_array($iterator));

输出

Array
(
    [0] => -4
    [1] => -3
    [2] => -2
    [3] => -1
    [4] => 0
    [8] => 5
)

ValuesIterator

类似于array_values()。

use Gielfeldt\Iterators\ValuesIterator;

$input = new \ArrayIterator([
    'key1' => 'value1',
    'key2' => 'value2',
    'key3' => 'value3',
]);

$iterator = new ValuesIterator($input);

print_r(iterator_to_array($iterator));

输出

Array
(
    [0] => value1
    [1] => value2
    [2] => value3
)

不是迭代器...

这些都是SPL文件处理的扩展。

CsvFileObject

AtomicTempFileObject

AtomicTempFileObjects

CsvFileObject

是SplFileObject在csv模式下的扩展，但支持csv头。

use Gielfeldt\Iterators\CsvFileObject;

// Load csv file and dump it.
$file = new CsvFileObject('somefile.csv');
print_r(iterator_to_array($file));

// Same but csv comes via a string variable.
$csvdata = "Columm1,Column2\nValue1,Value2\nValue3,Value4";
$file = new CsvFileObject('data://application/octet,' . $csvdata);
print_r(iterator_to_array($file));

输出

Array
(
    [0] => Array
        (
            [Columm1] => Value1
            [Column2] => Value2
        )

    [1] => Array
        (
            [Columm1] => Value3
            [Column2] => Value4
        )

)
Array
(
    [0] => Array
        (
            [Columm1] => Value1
            [Column2] => Value2
        )

    [1] => Array
        (
            [Columm1] => Value3
            [Column2] => Value4
        )

)

AtomicTempFileObject

AtomicTempFileObjects

辅助函数

包含各种辅助方法。

迭代器

use Gielfeldt\Iterators\Iterator;

$input = new \ArrayIterator([1,2,3,4,5,6]);
var_dump(Iterator::sum($input));
var_dump(Iterator::product($input));
var_dump(Iterator::average($input));
var_dump(Iterator::min($input));
var_dump(Iterator::max($input));

输出

int(21)

int(720)

double(3.5)

int(1)

int(6)

注意事项

可能有很多。

gielfeldt / iterators

维护者

详情

README

安装

迭代器

CachingIterator

ChecksumIterator

ChunkIterator

CloningIterator

CombineIterator

CountableIterator

DiffIterator

FiniteIterator

FlipIterator

GlobIterator

IndexIterator

InfiniteIterator

InterleaveIterator

IntersectIterator

TraversableIterator

KeysIterator

MapIterator

RandomIterator

RepeatIterator

ReplaceableIterator

ReservoirSamplingIterator

ShuffleIterator

SortIterator

StepIterator

UniqueIterator

ValuesIterator

不是迭代器...

CsvFileObject

AtomicTempFileObject

AtomicTempFileObjects

辅助函数

迭代器

注意事项