mf / callback-parser
PHP parser for arrow functions
Installs: 28 739
Dependents: 0
Suggesters: 0
Security: 0
Stars: 0
Watchers: 3
Forks: 1
Open Issues: 0
Requires
- php: ^7.1
- ext-mbstring: *
- beberlei/assert: ^2.7 || ^3.0
Requires (Dev)
- lmc/coding-standard: ^1.1
- php-coveralls/php-coveralls: ^2.1
- phpstan/phpstan-shim: ^0.10
- phpunit/phpunit: ^7.0
README
PHP parser for arrow functions
This library is no longer supported, since the arrow functions are natively in PHP 7.4 - https://www.php.net/manual/en/functions.arrow.php
Table of Contents
Requirements
- PHP 7.1
eval()
function for parsing Arrow Functions
Installation:
composer require mf/callback-parser
Arrow Functions
Usage:
$callbackParser = new CallbackParser(); $callback = $callbackParser->parseArrowFunction('($a, $b) => $a + $b'); var_dump($callback(2, 3)); // int 5
With Custom Exception
$callbackParser = new CallbackParser(App\MyCustomException::class); $callbackParser->parseArrowFunction('invalid'); // throws App\MyCustomException
How does it work?
- it parses function from string and evaluate it with
eval()
Possibly WTF?
This parser can parse an arrow function into PHP to be execute as usual.
But this process could be a little bit more complex than just eval
it.
You can check CallbackParserTest::provideInvalidFunction()
for examples.
Namespaces of parameters
For example namespace of class for given parameter type.
(SimpleEntity $entity) => $entity->getId()
This example above shows an INVALID
arrow function to be parsed (yet?).
Theres more reasons for this is an invalid
one:
- callback is parsed and
eval
ed elsewhere of scope, where you give such a callback - so
CallbackParser
does not knowSimpleEntity
full class name
There is more ways to 'fix' it, like:
- you can register a class map of allowed parameter types and parser could find a relevant one and use a full class name from the map, but IMHO this could be more complex than it should be
- parser could also find a relevant class in you entire project and magically use one of the most relevant, but it's a dark magic and I'd rather avoid it
Question is - is it really necessary?
I dont think so. Because PHP is quite powerful (weak
) and allows you
to use class methods of an object even if you don't know what they are.
But since the original purpose of this parser was to parse a callbacks on Collections,
you have other ways to know and verify a object type in parameter, so you can simply use those methods right away.
$list = new Generic\ListCollection(SimpleEntity::class); $list->add(new SimpleEntity(1)); $list->add(new SimpleEntity(2)); $ids = $list->map('($entity) => $entity->getId()'); var_dump($ids); //array (size=2) // 0 => int 1 // 1 => int 2
Simple simpler and complex still simply - 80:20
IMHO this parser allows you to parse simple functions simply, and you can still write a complex functions like PHP allows you.