YaLinqo: Yet Another LINQ to Objects for PHP
Features
- The most complete port of .NET LINQ to PHP, with many additional methods.
- Lazy evaluation, error messages and other behavior of original LINQ.
- Detailed PHPDoc and online reference based on PHPDoc for all methods. Articles are adapted from original LINQ documentation from MSDN.
- 100% unit test coverage.
- Best performance among full-featured LINQ ports (YaLinqo, Ginq, Pinq), at least 2x faster than the closest competitor, see performance tests.
- Callback functions can be specified as closures (like
function ($v) { return $v; }), PHP "function pointers" (either strings like'strnatcmp'or arrays likearray($object, 'methodName')), string "lambdas" using various syntaxes ('"$k = $v"','$v ==> $v+1','($v, $k) ==> $v + $k','($v, $k) ==> { return $v + $k; }'). - Keys are as important as values. Most callback functions receive both values and the keys; transformations can be applied to both values and the keys; keys are never lost during transformations, if possible.
- SPL interfaces
Iterator,IteratorAggregateetc. are used throughout the code and can be used interchangeably with Enumerable. - Redundant collection classes are avoided, native PHP arrays are used everywhere.
- Composer support (package on Packagist).
- No external dependencies.
Implemented methods
Some methods had to be renamed, because their names are reserved keywords. Original methods names are given in parenthesis.
- Generation: cycle, emptyEnum (empty), from, generate, toInfinity, toNegativeInfinity, matches, returnEnum (return), range, rangeDown, rangeTo, repeat, split;
- Projection and filtering: cast, ofType, select, selectMany, where;
- Ordering: orderBy, orderByDescending, orderByDir, thenBy, thenByDescending, thenByDir;
- Joining and grouping: groupJoin, join, groupBy;
- Aggregation: aggregate, aggregateOrDefault, average, count, max, maxBy, min, minBy, sum;
- Set: all, any, append, concat, contains, distinct, except, intersect, prepend, union;
- Pagination: elementAt, elementAtOrDefault, first, firstOrDefault, firstOrFallback, last, lastOrDefault, lastOrFallback, single, singleOrDefault, singleOrFallback, indexOf, lastIndexOf, findIndex, findLastIndex, skip, skipWhile, take, takeWhile;
- Conversion: toArray, toArrayDeep, toList, toListDeep, toDictionary, toJSON, toLookup, toKeys, toValues, toObject, toString;
- Actions: call (do), each (forEach), write, writeLine.
In total, more than 80 methods.
Example
Process sample data:
// Data
$products = array(
array('name' => 'Keyboard', 'catId' => 'hw', 'quantity' => 10, 'id' => 1),
array('name' => 'Mouse', 'catId' => 'hw', 'quantity' => 20, 'id' => 2),
array('name' => 'Monitor', 'catId' => 'hw', 'quantity' => 0, 'id' => 3),
array('name' => 'Joystick', 'catId' => 'hw', 'quantity' => 15, 'id' => 4),
array('name' => 'CPU', 'catId' => 'hw', 'quantity' => 15, 'id' => 5),
array('name' => 'Motherboard', 'catId' => 'hw', 'quantity' => 11, 'id' => 6),
array('name' => 'Windows', 'catId' => 'os', 'quantity' => 666, 'id' => 7),
array('name' => 'Linux', 'catId' => 'os', 'quantity' => 666, 'id' => 8),
array('name' => 'Mac', 'catId' => 'os', 'quantity' => 666, 'id' => 9),
);
$categories = array(
array('name' => 'Hardware', 'id' => 'hw'),
array('name' => 'Operating systems', 'id' => 'os'),
);
// Put products with non-zero quantity into matching categories;
// sort categories by name;
// sort products within categories by quantity descending, then by name.
$result = from($categories)
->orderBy('$cat ==> $cat["name"]')
->groupJoin(
from($products)
->where('$prod ==> $prod["quantity"] > 0')
->orderByDescending('$prod ==> $prod["quantity"]')
->thenBy('$prod ==> $prod["name"]'),
'$cat ==> $cat["id"]', '$prod ==> $prod["catId"]',
'($cat, $prods) ==> array(
"name" => $cat["name"],
"products" => $prods
)'
);
// Alternative shorter syntax using default variable names
$result2 = from($categories)
->orderBy('$v["name"]')
->groupJoin(
from($products)
->where('$v["quantity"] > 0')
->orderByDescending('$v["quantity"]')
->thenBy('$v["name"]'),
'$v["id"]', '$v["catId"]',
'array(
"name" => $v["name"],
"products" => $e
)'
);
// Closure syntax, maximum support in IDEs, but verbose and hard to read
$result3 = from($categories)
->orderBy(function ($cat) { return $cat['name']; })
->groupJoin(
from($products)
->where(function ($prod) { return $prod["quantity"] > 0; })
->orderByDescending(function ($prod) { return $prod["quantity"]; })
->thenBy(function ($prod) { return $prod["name"]; }),
function ($cat) { return $cat["id"]; },
function ($prod) { return $prod["catId"]; },
function ($cat, $prods) {
return array(
"name" => $cat["name"],
"products" => $prods
);
}
);
print_r($result->toArrayDeep());
Output (compacted):
Array (
[hw] => Array (
[name] => Hardware
[products] => Array (
[0] => Array ( [name] => Mouse [catId] => hw [quantity] => 20 [id] => 2 )
[1] => Array ( [name] => CPU [catId] => hw [quantity] => 15 [id] => 5 )
[2] => Array ( [name] => Joystick [catId] => hw [quantity] => 15 [id] => 4 )
[3] => Array ( [name] => Motherboard [catId] => hw [quantity] => 11 [id] => 6 )
[4] => Array ( [name] => Keyboard [catId] => hw [quantity] => 10 [id] => 1 )
)
)
[os] => Array (
[name] => Operating systems
[products] => Array (
[0] => Array ( [name] => Linux [catId] => os [quantity] => 666 [id] => 8 )
[1] => Array ( [name] => Mac [catId] => os [quantity] => 666 [id] => 9 )
[2] => Array ( [name] => Windows [catId] => os [quantity] => 666 [id] => 7 )
)
)
)
Requirements
- Version 1 (stable): PHP 5.3 or higher.
- Version 2 (stable): PHP 5.5 or higher.
- Version 3 (pre-alpha): PHP 7.0 or higher.
Usage
Add to composer.json:
{
"require": {
"athari/yalinqo": "^2.0"
}
}
Add to your PHP script:
require_once 'vendor/autoloader.php';
use \YaLinqo\Enumerable;
// 'from' can be called as a static method or via a global function shortcut
Enumerable::from(array(1, 2, 3));
from(array(1, 2, 3));
License
Simplified BSD License
Copyright © 2012–2018, Alexander Prokhorov
All rights reserved.
Links
YaLinqo Articles
-
CodeProject (English):
- LINQ for PHP comparison: YaLinqo, Ginq, Pinq — performance comparison of full-featured LINQ ports, with some additional information.
-
Habrahabr (Russian):
- Comparison of old LINQ libraries — comparison of LINQ for PHP, Phinq, PHPLinq and Plinq, also Underscore.php.
- YaLinqo 1.0 with updated comparison — explanation of architecture and design decisions.
- YaLinqo 2.0 — switch to PHP 5.5 with generators support and related changes.
- LINQ for PHP: speed matters — performance comparison of full-featured LINQ ports (YaLinqo, Ginq, Pinq).
-
Other (English):
- Tute Wall: How to use Linq in PHP by Mr. X — a series of posts covering basic usage of YaLinqo.
Related projects
- linq.js — LINQ for JavaScript. The one and only complete port of .NET LINQ to JavaScript.
- Underscore.js — library for functional programming in JavaScript. Similar to LINQ, but different method names and no lazy evaluation.
- Underscore.php — port of Underscore.js to PHP.
- RxPHP — reactive (push) counterpart of the active (pull) LINQ, port of Rx.NET.
- YaLinqoPerf — collection of performance tests comparing raw PHP, array functions, YaLinqo, YaLinqo with string lambdas, Ginq, Ginq with property accessors, Pinq.
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