sgh / comparable
Provides Comparable and Comparator interfaces and methods to sort and compare objects based on these.
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Requires
- php: >=5.4.0
Requires (Dev)
- phpunit/phpunit: 4.*
This package is not auto-updated.
Last update: 2024-10-26 18:01:05 UTC
README
This package, formerly known as Comparator Tools, provides sorting of objects
that have a Comparable interface and other useful functions with comparison of
objects. With these tools the Comparable
and Comparator
interfaces can be
used as known from Java.
Requirements
The package requires PHP 5.4 or later. The 2.x
branch requires PHP 5.6 or later.
Install
Via Composer
$ composer require sgh/comparable
Usage
To give your classes the comparable functionality, implement the Comparable interface:
use SGH\Comparable\Comparable;
class Foo implements Comparable
{
public function compareTo($object)
{
// if $this less than $object, return -1
// if $this equals $object, return 0
// if $this greater than $object, return 1
}
}
The compareTo method will be called with another instance of Foo as parameter
and must return a negative integer value if ($this < $object) applies and a
positive integer value if ($this > $object) applies, 0 otherwise (the objects
are considered equal). Note that non-integer values will be cast to (int), so
that 0.5
will be treated as 0
.
To sort or compare objects with the Comparable interface, you can use the
methods in SortFunctions
and SetFunctions
.
Sorting
use SGH\Comparable\SortFunctions;
SortFunctions::sort($arrayOfFoo);
SortFunctions::asort($arrayOfFoo);
SortFunctions::rsort($arrayOfFoo);
SortFunctions::arsort($arrayOfFoo);
SortFunctions::multisort($arrayOfFoo, $arbitraryArray, ...);
The first four methods work analogous to the respective core functions sort
,
asort
, rsort
and arsort
. multisort
works like array_multisort
in the
"sort multiple arrays" mode, i.e. the first passed array is sorted with the
Comparable interface, the others are re-ordered in the same way as the first.
Comparing
use SGH\Comparable\SetFunctions;
$diff = SetFunctions::diff($arrayOfFoo1, $arrayOfFoo2, ...);
$diff = SetFunctions::diff_assoc($arrayOfFoo1, $arrayOfFoo2, ...);
$intersect = SetFunctions::intersect($arrayOfFoo1, $arrayOfFoo2, ...);
$intersect = SetFunctions::intersect_assoc($arrayOfFoo1, $arrayOfFoo2, ...);
$unique = SetFunctions::unique($arrayOfFoo);
The methods work analogous to the respective core functions array_diff
,
array_diff_assoc
, array_intersect
, array_intersect_assoc
and
array_unique
. They treat objects $a
and $b
as equal if and only if
$a->compareTo($b) == 0
.
Comparators
It is also possible to implement the comparison in comparator classes to keep it separated from the objects to compare. This way comparison can be implemented for any values:
use SGH\Comparable\Comparator;
class FooComparator implements Comparator
{
public function compare($object1, $object2)
{
// if $object1 less than $object2, return -1
// if $object1 equals $object2, return 0
// if $object1 greater than $object2, return 1
}
}
The compare method is defined just like the compareTo method but both objects are passed as parameters.
To use a comparator, pass it as last argument to any method of SetFunctions
and SortFunctions
:
use SGH\Comparable\SortFunctions;
use SGH\Comparable\SetFunctions;
SortFunctions::sort($arrayOfFoo, new FooComparator);
SortFunctions::asort($arrayOfFoo, new FooComparator);
SortFunctions::rsort($arrayOfFoo, new FooComparator);
SortFunctions::arsort($arrayOfFoo, new FooComparator);
SortFunctions::multisort($arrayOfFoo, $arbitraryArray, ..., new FooComparator);
$diff = SetFunctions::diff($arrayOfFoo1, $arrayOfFoo2, ..., new FooComparator);
$diff = SetFunctions::diff_assoc($arrayOfFoo1, $arrayOfFoo2, ..., new FooComparator);
$intersect = SetFunctions::intersect($arrayOfFoo1, $arrayOfFoo2, ..., new FooComparator);
$intersect = SetFunctions::intersect_assoc($arrayOfFoo1, $arrayOfFoo2, ..., new FooComparator);
$unique = SetFunctions::unique($arrayOfFoo, new FooComparator);
The ObjectComparator
The package comes with an ObjectComparator
that compares equality of objects
(i.e. if two variables contain the same instance). It provides no useful sort
order but can be used with the methods in SetFunctions
(the core functions
array_diff
etc. cannot compare objects, they try to cast them to string for
comparison).
use SGH\Comparable\SetFunctions;
use SGH\Comparable\Comparator\ObjectComparator;
$diff = SetFunctions::diff($arrayOfObjects1, $arrayOfObjects2, new ObjectComparator);
// .. and so on
The following shortcut methods exist:
SetFunctions::objectsDiff($arrayOfObjects1, $arrayOfObjects2);
SetFunctions::objectsIntersect($arrayOfObjects1, $arrayOfObjects2);
SetFunctions::objectsUnique($arrayOfObjects);
SortedIterator
You can sort iterators as well. Due to the nature of iterators, this means
essentially that they get iterated over once, and you get an ArrayIterator
with all resulting items, sorted. To sort an iterator, decorate it with the
SortedIterator
like this:
use SGH\Comparable\SortFunctions;
$sortedIterator = SortFunctions::sortedIterator($iterator);
Exceptions
The default comparator throws a ComparatorException
if one of the objects
does not implement the Comparable
interface.
You are encouraged to throw a ComparatorException
in your compare()
or
compareTo()
implementations if the objects are not comparable to each other.
In most cases you should do it if the objects are not of expected type.
Testing
$ phpunit
Contributing
Please see CONTRIBUTING for details.
Security
If you discover any security related issues, please email fschmengler@sgh-it.eu instead of using the issue tracker.
Credits
- Fabian Schmengler(https://github.com/schmengler)
- All Contributors
License
The MIT License (MIT). Please see License File for more information.