Flow

php\util\Flow

implements: Iterator

A special class to work with arrays and iterators under flows. Flows are used for the lazy array/iterator operations, to save the RAM memory.

Class Flow, Immutable

Methods

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__construct($collection)

Create a new flow, you can also use of() method

Параметры:

• $collection – array, Iterator

withKeys()

Enables to save keys for the next operation

Результат:php\util\Flow

onlyKeys($keys, $ignoreCase = false)

Параметры:

• $keys – array, Traversable
• $ignoreCase – bool

Результат:

php\util\Flow

append($collection)

Appends a new collection to the current flow, do not remember that you can pass a flow to this method

Параметры:

• $collection – array, Iterator

Результат:

php\util\Flow

find($filter = null)

Finds elements by using the $filter callback, elements - for each iteration that returns true

Параметры:

• $filter – callable

Результат:

php\util\Flow

findOne($filter = null)

Finds the first element by using the $filter callback, when $filter will return the first true

Параметры:

• $filter – callable

Результат:

mixed

findValue($value, $strict = false)

Параметры:

• $value –
• $strict – bool

Результат:

int, null, string return null if not found, else - key of value

group($callback)

Параметры:

• $callback – callable

Результат:

php\util\Flow

each($callback)

Iterates elements. It will break if $callback returns false strongly

Параметры:

• $callback – callable - ($el[, $key]): bool

Результат:

int - iteration count

eachSlice($sliceSize, $callback, $withKeys = false)

Iterates elements as slices (that are passing as arrays to $callback). It will break if $callback returns false strongly

Параметры:

• $sliceSize – int
• $callback – callable - (array $items): bool
• $withKeys – bool

Результат:

int - slice iteration count

map($callback)

Iterates elements and returns a new flow of the result Example:

$newFlow = Flow::of([1,2,3])->map(function($el){  return $el * 10 });

// the new flow will contain 10, 20 and 30

Параметры:

• $callback – callable - ($el[, $key])

Результат:

php\util\Flow

keys()

Create a new flow by using the keys of the current flow

Результат:php\util\Flow

skip($n)

Skips $n elements in the current collection

Параметры:

• $n – int - skip count

Результат:

php\util\Flow

limit($count)

Limits collection with $count

Параметры:

• $count – int - count of limit

Результат:

php\util\Flow

reduce($callback)

Iterates elements and gets a result of this operation It can be used for calculate some results, for example:

// calculates a sum of elements

$sum = .. ->reduce(function($result, $el){ $result = $result + $el });

Параметры:

• $callback – callable - ($result, $el[, $key])

Результат:

int

sort($comparator = null)

Sort the last result of the flow, also see: php\\lib\\items::sort()

Примечание

use the withKeys() method to save keys

Параметры:

• $comparator – callable - ($o1, $o2) -> int, where -1 smaller, 0 equal, 1 greater

Результат:

array

sortByKeys($comparator = null)

The same method as sort() only based on keys insteadof values

Примечание

use the withKeys() method to save keys

Параметры:

• $comparator – callable - ($key1, $key2) -> int

Результат:

array

toArray()

Convert elements to an array

Примечание

use the withKeys() method to save keys

Результат:array

toString($separator)

Join elements to a string similar to implode() in PHP

Параметры:

• $separator – string

Результат:

string

count()

Результат:int

current()

Результат:mixed

next()

Результат:void

key()

Результат:mixed

valid()

Результат:bool

rewind()

Результат:void

__clone()

private

static ofEmpty

Результат:php\util\Flow

static of($collection)

Creates a new flow for an array of Iterator

Параметры:

• $collection – array, Traversable

Результат:

php\util\Flow

static ofRange($from, $to, $step = 1)

Creates a new flow for a number range

Параметры:

• $from – int
• $to – int
• $step – int

Результат:

php\util\Flow

static ofString($string, $chunkSize = 1)

Creates a new flow for the string

Параметры:

• $string – string
• $chunkSize – int - how many characters to combine for one item ?

Результат:

php\util\Flow

static ofStream($stream, $chunkSize = 1)

Creates a new flow for the Stream object

Параметры:

• $stream – php\io\Stream - stream object
• $chunkSize – int - size for Stream.read($size) method

Результат:

php\util\Flow