/**
* Returns an infinite, traversable sequence that exponentially grows by given percentage
*
* @param integer $start
* @param integer $percentage Integer between 1 and 100
* @return ExponentialSequence
* @throws InvalidArgumentException
*/
function sequence_exponential($start, $percentage)
{
InvalidArgumentException::assertIntegerGreaterThanOrEqual($start, 1, __METHOD__, 1);
InvalidArgumentException::assertIntegerGreaterThanOrEqual($percentage, 1, __METHOD__, 2);
InvalidArgumentException::assertIntegerLessThanOrEqual($percentage, 100, __METHOD__, 2);
return new ExponentialSequence($start, $percentage);
}
/**
* Retry a callback until the number of retries are reached or the callback does no longer throw an exception
*
* @param callable $callback
* @param integer $retries
* @param Traversable|null $delaySequence Default: no delay between calls
* @throws Exception Any exception thrown by the callback
* @throws InvalidArgumentException
* @return mixed Return value of the function
*/
function retry(callable $callback, $retries, Traversable $delaySequence = null)
{
InvalidArgumentException::assertIntegerGreaterThanOrEqual($retries, 1, __FUNCTION__, 2);
if ($delaySequence) {
$delays = new AppendIterator();
$delays->append(new InfiniteIterator($delaySequence));
$delays->append(new InfiniteIterator(new ArrayIterator([0])));
$delays = new LimitIterator($delays, $retries);
} else {
$delays = array_fill_keys(range(0, $retries), 0);
}
$retry = 0;
foreach ($delays as $delay) {
try {
return $callback($retry, $delay);
} catch (Exception $e) {
if ($retry === $retries - 1) {
throw $e;
}
}
if ($delay > 0) {
usleep($delay);
}
++$retry;
}
}
/**
* Recombines arrays by index and applies a callback optionally
*
* @param $args array|Traversable $collection One or more callbacks
* @return array
*/
function zip($arg)
{
$args = func_get_args();
$callback = null;
if (is_callable(end($args))) {
$callback = array_pop($args);
}
foreach ($args as $position => $arg) {
InvalidArgumentException::assertCollection($arg, __FUNCTION__, $position + 1);
}
$result = [];
foreach ((array) reset($args) as $index => $value) {
$zipped = [];
foreach ($args as $arg) {
$zipped[] = isset($arg[$index]) ? $arg[$index] : null;
}
if ($callback !== null) {
/** @var callable $callback */
// $zipped = $callback(...$zipped);
$zipped = call_user_func_array($callback, $zipped);
}
$result[] = $zipped;
}
return $result;
}
public function __construct($start, $amount)
{
InvalidArgumentException::assertIntegerGreaterThanOrEqual($start, 0, __METHOD__, 1);
InvalidArgumentException::assertInteger($amount, __METHOD__, 2);
$this->start = $start;
$this->amount = $amount;
}
/**
* Returns a function that invokes method `$method` with arguments `$methodArguments` on the object
*
* @param string $methodName
* @param array $arguments
* @return callable
*/
function invoker($methodName, array $arguments = [])
{
InvalidArgumentException::assertMethodName($methodName, __FUNCTION__, 1);
return static function ($object) use($methodName, $arguments) {
return $object->{$methodName}(...$arguments);
};
}
/**
* Recombines arrays by index (column) and applies a callback optionally
*
* When the input collections are different lengths the resulting collections
* will all have the length which is required to fit all the keys
*
* @param $args array|Traversable $collection One or more callbacks
* @return array
*/
function zip_all(...$args)
{
/** @var callable|null $callback */
$callback = null;
if (is_callable(end($args))) {
$callback = array_pop($args);
}
foreach ($args as $position => $arg) {
InvalidArgumentException::assertCollection($arg, __FUNCTION__, $position + 1);
}
$resultKeys = [];
foreach ($args as $arg) {
foreach ($arg as $index => $value) {
$resultKeys[] = $index;
}
}
$resultKeys = array_unique($resultKeys);
$result = [];
foreach ($resultKeys as $key) {
$zipped = [];
foreach ($args as $arg) {
$zipped[] = isset($arg[$key]) ? $arg[$key] : null;
}
$result[$key] = $zipped;
}
if ($callback !== null) {
foreach ($result as $key => $column) {
$result[$key] = $callback(...$column);
}
}
return $result;
}
/**
* Iterates over a collection of elements, yielding each in turn to a callback function. Each invocation of $callback
* is called with three arguments: (element, index, collection)
*
* @param Traversable|array $collection
* @param callable $callback
* @return null
*/
function each($collection, callable $callback)
{
InvalidArgumentException::assertCollection($collection, __FUNCTION__, 1);
foreach ($collection as $index => $element) {
$callback($element, $index, $collection);
}
}
/**
* Memoizes callbacks and returns their value instead of calling them
*
* @param callable $callback Callable closure or function
* @param array $arguments Arguments
* @param array|string $key Optional memoize key to override the auto calculated hash
* @return mixed
*/
function memoize($callback, array $arguments = array(), $key = null)
{
static $storage = array();
if ($callback === null) {
$storage = array();
return null;
}
InvalidArgumentException::assertCallback($callback, __FUNCTION__, 1);
static $keyGenerator = null;
if (!$keyGenerator) {
$keyGenerator = function ($value) use(&$keyGenerator) {
$type = gettype($value);
if ($type === 'array') {
$key = join(':', map($value, $keyGenerator));
} elseif ($type === 'object') {
$key = get_class($value) . ':' . spl_object_hash($value);
} else {
$key = (string) $value;
}
return $key;
};
}
if ($key === null) {
$key = $keyGenerator(array_merge(array($callback), $arguments));
} else {
$key = $keyGenerator($key);
}
if (!isset($storage[$key]) && !array_key_exists($key, $storage)) {
$storage[$key] = call_user_func_array($callback, $arguments);
}
return $storage[$key];
}
/**
* Iterates over a collection of elements, yielding each in turn to a callback function. Each invocation of $callback
* is called with three arguments: (element, index, collection)
*
* @param Traversable|array $collection
* @param callable $callback
* @return null
*/
function each($collection, $callback)
{
InvalidArgumentException::assertCollection($collection, __FUNCTION__, 1);
InvalidArgumentException::assertCallback($callback, __FUNCTION__, 2);
foreach ($collection as $index => $element) {
call_user_func($callback, $element, $index, $collection);
}
}
public function testHashIterator()
{
$flat = flat_map(new ArrayIterator(['ka' => 'a', 'kb' => ['b'], 'kc' => ['C' => 'c'], 'kd' => [['d']], 'ke' => null, null]), function ($v, $k, $collection) {
InvalidArgumentException::assertCollection($collection, __FUNCTION__, 3);
return $v;
});
$this->assertSame(['a', 'b', 'c', ['d']], $flat);
}
/**
* Alias for Functional\first
*
* @param Traversable|array $collection
* @param callable $callback
* @return mixed
*/
function head($collection, $callback = null)
{
InvalidArgumentException::assertCollection($collection, __FUNCTION__, 1);
if ($callback !== null) {
InvalidArgumentException::assertCallback($callback, __FUNCTION__, 2);
}
return first($collection, $callback);
}
/**
* @param Traversable|array $collection
* @param callable $callback
* @param mixed $initial
* @return array
*/
function reduce_left($collection, callable $callback, $initial = null)
{
InvalidArgumentException::assertCollection($collection, __FUNCTION__, 1);
foreach ($collection as $index => $value) {
$initial = $callback($value, $index, $collection, $initial);
}
return $initial;
}
public function __construct($start, $percentage)
{
InvalidArgumentException::assertIntegerGreaterThanOrEqual($start, 1, __METHOD__, 1);
InvalidArgumentException::assertIntegerGreaterThanOrEqual($percentage, 1, __METHOD__, 2);
InvalidArgumentException::assertIntegerLessThanOrEqual($percentage, 100, __METHOD__, 2);
$this->start = $start;
$this->percentage = $percentage;
}
public function testDuplicateKeys()
{
$fn = function ($v, $k, $collection) {
InvalidArgumentException::assertCollection($collection, __FUNCTION__, 3);
return $k[0];
};
$this->assertSame(['k' => 'val2'], reindex($this->hash, $fn));
}
/**
* Produces a new array of elements by mapping each element in collection through a transformation function (callback).
* Callback arguments will be element, index, collection
*
* @param Traversable|array $collection
* @param callable $callback
* @return array
*/
function map($collection, callable $callback)
{
InvalidArgumentException::assertCollection($collection, __FUNCTION__, 1);
$aggregation = [];
foreach ($collection as $index => $element) {
$aggregation[$index] = $callback($element, $index, $collection);
}
return $aggregation;
}
/**
* Returns true if all of the elements in the collection pass the callback falsy test. Opposite of Functional\all().
* Callback arguments will be element, index, collection.
*
* @param Traversable|array $collection
* @param callable $callback
* @return bool
*/
function none($collection, callable $callback)
{
InvalidArgumentException::assertCollection($collection, __FUNCTION__, 1);
foreach ($collection as $index => $element) {
if ($callback($element, $index, $collection)) {
return false;
}
}
return true;
}
/**
* Returns a function that expects an object as the first param and tries to invoke the given method on it
*
* @param string $methodName
* @param array $arguments
* @param mixed $defaultValue
* @return callable
*/
function partial_method($methodName, array $arguments = [], $defaultValue = null)
{
InvalidArgumentException::assertMethodName($methodName, __FUNCTION__, 1);
return function ($object) use($methodName, $arguments, $defaultValue) {
if (!is_callable([$object, $methodName])) {
return $defaultValue;
}
return $object->{$methodName}(...$arguments);
};
}
/**
* Takes a nested combination of collections and returns their contents as a single, flat array.
* Does not preserve indexs.
*
* @param Traversable|array $collection
* @return array
*/
function flatten($collection)
{
Exceptions\InvalidArgumentException::assertCollection($collection, __FUNCTION__, 1);
$it = new RecursiveIteratorIterator(new RecursiveArrayIterator($collection));
$result = array();
foreach ($it as $val) {
$result[] = $val;
}
return $result;
}
/**
* Partitions a collection by callback result. The truthy partition is the first one
* (array index "0"), the falsy the second one (array index "1")
*
* @param Traversable|array $collection
* @param callable $callback
* @return array
*/
function partition($collection, callable $callback)
{
InvalidArgumentException::assertCollection($collection, __FUNCTION__, 1);
$partitions = [0 => [], 1 => []];
foreach ($collection as $index => $element) {
$partitionKey = $callback($element, $index, $collection) ? 0 : 1;
$partitions[$partitionKey][$index] = $element;
}
return $partitions;
}
/**
* Produces a new array of elements by mapping each element in collection through a transformation function (callback).
* Callback arguments will be element, index, collection
*
* @param Traversable|array $collection
* @param callable $callback
* @return array
*/
function map($collection, $callback)
{
InvalidArgumentException::assertCollection($collection, __FUNCTION__, 1);
InvalidArgumentException::assertCallback($callback, __FUNCTION__, 2);
$aggregation = array();
foreach ($collection as $index => $element) {
$aggregation[$index] = call_user_func($callback, $element, $index, $collection);
}
return $aggregation;
}
/**
* Returns true if the collection contains the given value. If the third parameter is
* true values will be compared in strict mode
*
* @param Traversable|array $collection
* @param mixed $value
* @param bool $strict
* @return bool
*/
function contains($collection, $value, $strict = true)
{
InvalidArgumentException::assertCollection($collection, __FUNCTION__, 1);
foreach ($collection as $element) {
if ($value === $element || !$strict && $value == $element) {
return true;
}
}
return false;
}
/**
* Returns true if all elements of the collection are strictly true
*
* @param Traversable|array $collection
* @return bool
*/
function true($collection)
{
InvalidArgumentException::assertCollection($collection, __FUNCTION__, 1);
foreach ($collection as $value) {
if ($value !== true) {
return false;
}
}
return true;
}
/**
* Takes a collection and returns the quotient of all elements
*
* @param Traversable|array $collection
* @param integer|float $initial
* @return integer|float
*/
function ratio($collection, $initial = 1)
{
InvalidArgumentException::assertCollection($collection, __FUNCTION__, 1);
$result = $initial;
foreach ($collection as $value) {
if (is_numeric($value)) {
$result /= $value;
}
}
return $result;
}
function test()
{
$fn = function ($v, $k, $collection) {
Exceptions\InvalidArgumentException::assertCollection($collection, __FUNCTION__, 1);
return $v > 2;
};
$this->assertSame(array(2 => 3, 3 => 4), tail($this->array, $fn));
$this->assertSame(array(2 => 3, 3 => 4), tail($this->iterator, $fn));
$this->assertSame(array(), tail($this->badArray, $fn));
$this->assertSame(array(), tail($this->badIterator, $fn));
}
function test()
{
$fn = function ($v, $k, $collection) {
Exceptions\InvalidArgumentException::assertCollection($collection, __FUNCTION__, 3);
return is_int($k) ? $k % 2 == 0 : $v[3] % 2 == 0;
};
$this->assertSame(array(array(0 => 'value1', 2 => 'value3'), array(1 => 'value2')), partition($this->array, $fn));
$this->assertSame(array(array(0 => 'value1', 2 => 'value3'), array(1 => 'value2')), partition($this->iterator, $fn));
$this->assertSame(array(array('k2' => 'val2'), array('k1' => 'val1', 'k3' => 'val3')), partition($this->hash, $fn));
$this->assertSame(array(array('k2' => 'val2'), array('k1' => 'val1', 'k3' => 'val3')), partition($this->hashIterator, $fn));
}
public function test()
{
$fn = function ($v, $k, $collection) {
InvalidArgumentException::assertCollection($collection, __FUNCTION__, 1);
return $v == 'first' && $k == 0 || $v == 'third' && $k == 2;
};
$this->assertSame('third', last($this->list, $fn));
$this->assertSame('third', last($this->listIterator, $fn));
$this->assertNull(last($this->badArray, $fn));
$this->assertNull(last($this->badIterator, $fn));
}
/**
* Invoke a callback on a value if the value is not null
*
* @param mixed $value
* @param callable $callback
* @return mixed
*/
function with($value, $callback)
{
InvalidArgumentException::assertCallback($callback, __FUNCTION__, 2);
if ($value === null) {
return null;
}
if (is_callable($value)) {
$value = $value();
}
return $callback($value);
}
/**
* @dataProvider getAliases
*/
function test($functionName)
{
$callback = function ($v, $k, $collection) {
Exceptions\InvalidArgumentException::assertCollection($collection, __FUNCTION__, 1);
return $v == 'second' && $k == 1;
};
$this->assertSame('second', $functionName($this->array, $callback));
$this->assertSame('second', $functionName($this->iterator, $callback));
$this->assertNull($functionName($this->badArray, $callback));
$this->assertNull($functionName($this->badIterator, $callback));
}
public function test()
{
$fn = function ($v, $k, $collection) {
InvalidArgumentException::assertCollection($collection, __FUNCTION__, 3);
return is_int($k) ? $k % 2 == 0 : $v[3] % 2 == 0 ? 'foo' : '';
};
$this->assertSame(['foo' => [0 => 'value1', 2 => 'value3'], '' => [1 => 'value2', 3 => 'value4']], group($this->list, $fn));
$this->assertSame(['foo' => [0 => 'value1', 2 => 'value3'], '' => [1 => 'value2', 3 => 'value4']], group($this->listIterator, $fn));
$this->assertSame(['' => ['k1' => 'val1', 'k3' => 'val3'], 'foo' => ['k2' => 'val2']], group($this->hash, $fn));
$this->assertSame(['' => ['k1' => 'val1', 'k3' => 'val3'], 'foo' => ['k2' => 'val2']], group($this->hashIterator, $fn));
}
function test()
{
$fn = function ($v, $k, $collection) {
Exceptions\InvalidArgumentException::assertCollection($collection, __FUNCTION__, 3);
return $v == 'wrong' && strlen($k) > 0;
};
$this->assertSame(array(0 => 'value', 2 => 'value'), reject($this->array, $fn));
$this->assertSame(array(0 => 'value', 2 => 'value'), reject($this->iterator, $fn));
$this->assertSame(array('k1' => 'value', 'k3' => 'value'), reject($this->hash, $fn));
$this->assertSame(array('k1' => 'value', 'k3' => 'value'), reject($this->hashIterator, $fn));
}
