shiyan/iterate

Iterates iterators by a scenario.

Iterate

, _(*1)

PHP classes and interfaces to iterate \Iterators by a scenario or to perform a regular expression match on iterator elements by a scenario., _(*2)

A Scenario is a class that implements the ScenarioInterface or extends either BaseScenario or BaseRegexScenario abstract class. It receives an Iterator instance and executes the logic in certain moments of the iteration process - for example, while regex matching is performed - when some pattern matched a subject, or none matched, or before/after performing a search, etc., _(*3)

Think of it as of array_walk() for iterators or iterator_apply(), but instead of a single callback you provide an object (Scenario) with several methods. And you can use these Scenarios as plugins., _(*4)

Iterator is simply any object implementing the \Iterator interface., _(*5)

The main class, which runs the process, is Iterate. It just needs to be instantiated and invoked with an iterator and a scenario objects., _(*6)

Best suited for use as a Composer library., _(*7)

Requirements

• PHP ≥ 7.1

Installation

To add this library to your Composer project:, _(*8)

composer require shiyan/iterate

Usage

There are 2 base scenarios included: * The very basic one to execute some logic on each element of the iterator unconditionally. * And the regex based one, which performs a regular expression match (using one or more patterns) on iterator elements (casted to strings), and allows to execute different logic depending on what pattern matched or if no patterns matched., _(*9)

Example

Assuming there is an array of strings, $array. Iterate over it, convert all empty strings to 0 (zero), print all strings containing "PHP" and simply count all other elements., _(*10)

First, create a scenario class:, _(*11)

use Shiyan\Iterate\Scenario\BaseRegexScenario;

class ExampleScenario extends BaseRegexScenario {

  const PATTERN_EMPTY = '/^$/';
  const PATTERN_PHP = '/PHP/';

  public $counter;

  public function getPatterns(): array {
    return [self::PATTERN_EMPTY, self::PATTERN_PHP];
  }

  public function preRun(): void {
    $this->counter = 0;
  }

  public function onMatch(array $matches, string $pattern): void {
    switch ($pattern) {
      case self::PATTERN_EMPTY:
        $this->iterator[$this->iterator->key()] = 0;
        break;

      case self::PATTERN_PHP:
        print $this->iterator->current() . "\n";
        break;
    }
  }

  public function ifNotMatched(): void {
    ++$this->counter;
  }

}

And then:, _(*12)

use Shiyan\Iterate\Iterate;

// Convert our array of strings to the iterator object.
$iterator = new ArrayIterator($array);
$scenario = new ExampleScenario();
$iterate = new Iterate();

// Invoke iterate with our scenario.
$iterate($iterator, $scenario);
print "Found {$scenario->counter} non-empty, non-PHP strings.\n";

// Let's check that empty strings were converted to zeros.
print_r($iterator->getArrayCopy());

// If we invoke Iterate with the same scenario once again, it won't find empty
// strings anymore. Instead, we'll have a higher number in the $counter property
// of the $scenario object, because the "0" doesn't match our patterns.
$iterate($iterator, $scenario);
print "Found {$scenario->counter} non-empty, non-PHP strings.\n";