Ginq

`LINQ to Object` inspired DSL for PHP

Description

Many functions in Ginq are evaluated in lazy, and no actions are taken until that time. This features bring you many benefits.

Code Quality Rank: L4

Programming language: PHP

License: MIT License

Tags: Data Structure And Storage     Iterator     DSL     Array     Linq    

Latest version: v0.2.4

README

Ginq

Array handling in PHP? Be happy with Ginq!

Ginq is a DSL that can handle arrays and iterators of PHP unified.

Ginq is inspired by Linq to Object, but is not a clone.

Many functions in Ginq are evaluated in lazy, and no actions are taken until that time. This features bring you many benefits.

Install

composer.json:

{
    "require": {
        "ginq/ginq": "dev-master"
    }
}

see: https://packagist.org/packages/ginq/ginq

Usage

$xs = Ginq::from(array(1,2,3,4,5,6,7,8,9,10))
        ->where(function($x) { return $x % 2 != 0; })
        ->select(function($x) { return $x * $x; });
        ;

You pass Ginq data and build a query with it. In this example above, you order Ginq to choose even numbers and square each of them.

But Ginq do nothing, Ginq knows only you want a result of chosen and squared numbers.

Let's execute foreach loop with Ginq to get the result.

foreach ($xs as $x) { echo "$x "; }

The result is

1 9 25 49 81

You got the expected result!

Next, you can get an array with toList.

$xs->toList();

array(1,9,25,49,81);

Ginq has functions, well-known in SQL, such as join(), orderBy(), and groupBy() other than select(), where() listed above.

Selector and Predicate

Most of methods in Ginq receive a closure as a argument.

You may not be familiar with closures, but it is very simple things. There are just three types of closures in Ginq, you can remember simply. These are predicate, selector, and connection selector.

Predicate

A closure that passed to a method that do select, such as where() is called predicate.

Predicate is a closure that receive a pair of key and values in the elements and return boolean value.

function ($v, [$k]) { return $v % 2 == 0; }

You get even numbers when you pass this closure to where(). You can skip second argument when you don't need it in the process.

Selector

A closure that passed to a method that do projection, such as select() is called selector.

Selector is a closure that receive a pair of key and value in the elements and create a new value or key, and then return it.

function ($v, [$k]) { return $v * $v ; }

You get squared numbers of original when you pass this closure to select().

This function is used to specify the key of grouping with groupBy(), the key of sorting with groupBy().

Connection Selector

Connection Selector is one of the selector that combine two elements into one, is used with join(), zip().

function ($v0, $v1, [$k0, $k1]) { return array($v0, $v1) ; }

This function receive 4 arguments, two values and two keys, and then create new value or key and return it. You can skip arguments when you don't need it in the process.

These are zip() example that combine each elements from two arrays.

$foods  = array("meat", "pasta", "salada");
$spices = array("time", "basil", "dill");

$xs = Ginq::from($foods)
        ->zip($spices, function($f, $s) {
            return "$f with $s!";
        })
        ;

foreach ($xs as $x) { echo "$x\n"; }

meat with time!
pasta with basil!
salada with dill!

Shortcuts of predicate and selector

Selector can receive a character string instead of a closure.

They return the value of the field when the element is an object, or return the value of the key when it is an array.

So,

Ginq::from($xs)->select('[key].property');

The example above is same as two examples below.

Ginq::from($xs)->select(
    function ($v, $k) { return $v['key'].property; }
);

see: Property Access (Symfony) http://symfony.com/doc/current/components/property_access/index.html

More complex examples

References

Development

PreRequirements

• Docker installed.
• Docker Compose installed.

How to start development (Run test)

• cd docker
• docker-compose up -d
• docker-compose exec php ash
• (in php container)
  • composer install
  • vendor/bin/phpunit

Note

• You can use illuminate/support library. (Laravel Collection, ...)