PHP code example of b2pweb / bdf-collections

    
        
<?php
require_once('vendor/autoload.php');

/* Start to develop here. Best regards https://php-download.com/ */

    

b2pweb / bdf-collections example snippets

$collection = new ArrayCollection(['foo']);

$collection->contains('foo'); // true
$collection->contains('bar'); // false

$collection->add('bar');
$collection->contains('bar'); // true
$collection->remove('bar');
$collection->contains('bar'); // false

$collection->add(42);
$collection->contains('42', true); // false
$collection->contains(42, true); // true

// Print "foo 42"
$collection->forEach (function ($value) {
    echo $value, ' ';
});

// Same as above
foreach ($collection as $value) {
    echo $value, ' ';
}

$table = new ArrayCollection(['foo' => 'bar']);

// Using methods
$table->contains('bar'); // true
$table->hasKey('foo'); // true
$table->get('foo'); // "bar"

$table->set('value', 42);
$table->contains(42); // true

// Using array access
isset($table['value']); // true
$table['value']; // 42

$table->values(); // ['bar', 42]
$table->keys(); // ['foo', 'value]

// Print "foo=bar value=42"
$table->forEach (function ($value, $key) {
    echo $key, '=', $value, ' ';
});

// Same as above
foreach ($table as $key => $value) {
    echo $key, '=', $value, ' ';
}

$collection = new OrderedCollection();

$collection->addAll([4, 9, 2, 7]);

$collection->contains(9); // true
$collection->search(4); // 1
$collection->at(2); // 7
$collection->toArray(); // [2, 4, 7, 9]

$collection->remove(7);
$collection->toArray(); // [2, 4, 9]

// Array access
$collection[0]; // 2
isset($collection[9]); // false : check the existence of the offset
isset($collection[1]); // true
$collection[] = 5; // Add the element 5
unset($collection[2]); // Remove the 3rd element (5)

// Prints 0=2 4=1 9=2
$collection->forEach(function ($element, $position) {
    echo "$position=$element ";
});

// Same as above
foreach ($collection as $position => $element) {
    echo "$position=$element ";
}

// A custom comparator can also be used
$collection = new OrderedCollection(function ($a, $b) {
    return $a->compute() - $b->compute();
});

$set = new HashSet();

$set->add('foo'); // true
$set->add('foo'); // false : already added
$set->contains('foo'); // true
$set->contains('not found'); // false

// Works also with array or objects
$set->add(['foo' => 'bar']);

$obj = new stdClass();
$set->add($obj);

$set->lookup(new stdClass())->get() === $obj; // Get the stored element, which is equals with the parameter
$set->loopup('not found')->empty(); // true : An empty optional is returned if the element is not found

$objectSet = HashSet::spl(); // Use spl_object_hash() as hash function

$obj1 = new stdClass();
$obj2 = new stdClass();

$objectSet->add($obj1);
$objectSet->contains($obj1); // true
$objectSet->contains($obj2); // false : not the same reference, hash is different

// Use HashTable with multiple-keys indexing using array
$table = new HashTable();

$table[[123, 'aze']] = new Entity(1);
$table[[456, 'rty']] = new Entity(2);

$table[[123, 'aze']]; // Returns Entity(1)

// Use object as key
$table[new Key()] = 'value';

$table->toArray(false); // Associative array is not possible : return in form [ [key, value], ... ]

// Create a case insensitive table by registering a custom hash function
$ciTable = new HashTable('strtolower'); // Transform keys to lower case

$ciTable->set('Foo', 'bar');
$ciTable->get('FOO'); // 'bar'

$stream = Streams::wrap([7, 4, 9]);

// [ 10 => 8, 16 => 14, 20 => 18]
$stream
    ->sort()
    ->map(function ($element) { return $element * 2; })
    ->mapKey(function ($element) { return $element + 2; })
    ->toArray()
;

$collection = new ArrayCollection([...]);

$stream = $collection->mutableStream(); // Get a mutable stream from an ArrayCollection
$stream = new MutableArrayStream([...]); // Or creates using constructor

// And use like other streams
$stream
    ->map(...)
    ->filter(...)
    ->collect(...)
;

// Creates the optional
Optional::empty(); // "Null" optional
Optional::of($myValue); // Wrap $myValue into an Optional. The value must not be null
Optional::nullable($myValue); // Wrap $myValue into an Optional. The value may be null

Optional::empty()->present(); // false
Optional::of(42)->present(); // true

// Creates a simple null object
$myNullObject = Optional::nullable($person);

$myNullObject->firstName()->or('undefined'); // Call $person->firstName() if present, and get the return value, or return "undefined"
isset($myNullObject->myProp); // Check if property myProp exists into $person 

$myNullObject->stream(); // Creates a singleton or empty stream with the wrapped element.