PHP Evolves After Three Decades: Includes Pipe Operator, Contemplates Generics
In a move to improve code expressiveness and type safety, PHP 8.5 is set to introduce partial generics and functional programming features, inspired by languages like F#. Here's a closer look at the new developments in PHP 8.5.
The State of Generics in PHP 8.5
The PHP Foundation and core developers are proposing a partial implementation of generics limited to interfaces and abstract classes, where generics would be used primarily at compile time rather than runtime. This approach aims to capture about 80% of the benefits of generics while avoiding the complexity and performance costs of a full generics implementation in an interpreted language like PHP [1].
This partial generics system would require implementing classes to specify the generic types declared by interfaces or abstract classes, enabling safer and clearer type usage resolved at compile time [1].
PHP 8.5 and Functional Programming
PHP 8.5 is also introducing features inspired by functional programming, such as the new pipe operator (), which enables function chaining and partial function application, similar to what is found in F# and other functional languages [2]. This operator may also enable partial function applications.
Potential Impact of Partial Generics in PHP 8.5
The potential impact of partial generics in PHP 8.5 includes:
- Improved type safety and developer experience for large codebases through compile-time checking of generic interfaces and abstract classes [1].
- More efficient type checking than full runtime generics, reducing performance overhead [1].
- Enabling better abstraction in libraries and frameworks by allowing parameterized types in interfaces and abstract classes [1].
- Combined with the pipe operator and partial function application, PHP is moving closer to functional programming idioms, which may improve readability and composability of PHP code [2].
Comparison to F
| Feature Aspect | PHP 8.5 Partial Generics | F# | |-------------------------------|----------------------------------------------------|----------------------------------------------| | Generics | Partial, limited to interfaces and abstract classes, compile-time only | Fully featured, used extensively with static type checking | | Type checking | Mostly compile-time, since runtime generics are complex in PHP | Fully static at compile time | | Functional programming support | Introducing pipe operator and partial function application | Native functional language with extensive FP features | | Performance considerations | Avoids runtime generics to maintain interpreter performance | Compiled with efficient type system |
The Future of PHP
PHP 8.5 is taking an incremental, pragmatic approach to generics by limiting their scope to a subset of types and doing type checking at compile time to avoid runtime costs. It is also adopting functional programming features like the pipe operator, inspired by languages like F#, but PHP remains fundamentally a dynamically typed language evolving towards safer, more expressive constructs without matching the full generics and functional capabilities that F# natively offers [1][2][3].
With these new developments, PHP continues to power more than 70 percent of websites using server-side programming, largely due to WordPress and other content-management systems. The future of PHP looks promising as it continues to adapt and grow to meet the needs of developers and the ever-evolving web landscape.
[1] https://wiki.php.net/rfc/generics [2] https://wiki.php.net/rfc/pipe [3] https://www.infoq.com/news/2021/05/php-8-5-generics-functional-programming/
- The introduction of partial generics in PHP 8.5, limited to interfaces and abstract classes, could increase the code's expressiveness and type safety, mirroring advances in other technology such as software inspired by languages like F#.
- To achieve better abstraction in libraries and frameworks, PHP 8.5's partial generics system may enable parameterized types in interfaces and abstract classes, reducing potential errors at runtime and setting the stage for functional programming features like the new pipe operator.
