Functional programming with PHP and Haskell
With the development of the Internet, programming languages are constantly updated and improved. Nowadays, various programming languages emerge in endlessly, and two of them, PHP and Haskell, have attracted much attention among developers.
PHP is a very popular server-side scripting language used for rapid development of web applications. PHP is widely used in many fields such as web development, dynamic page generation, and server-side scripting.
Haskell is a strongly typed pure functional programming language. It has all the advantages of functional programming languages, such as concise code, easy maintenance, high code reuse rate, etc.
Although the two programming languages PHP and Haskell seem to have very different styles, in fact they both support functional programming style. This article will introduce how to use PHP and Haskell for functional programming.
- Functional programming in PHP
Functional programming in PHP is mainly implemented through anonymous functions, higher-order functions and closures.
1.1 Anonymous function
The anonymous function in PHP is a function without a function name and can be called directly through variables. Anonymous functions can be used to conveniently define some temporary functions, and are usually used as parameters of higher-order functions.
$greet = function($name) { echo "Hello {$name}!"; }; $greet('World');
1.2 Higher-order functions
Higher-order functions refer to functions that can take functions as parameters or return values. PHP also supports higher-order functions, and by using anonymous functions, functions can be encapsulated and called conveniently.
function apply($callback, $value) { return $callback($value); } $addThree = function($x) { return $x + 3; }; echo apply($addThree, 5); // 输出 8
1.3 Closure
Closure refers to a function that can access external variables. It is usually implemented by defining an anonymous function inside the function. In PHP, you can use closures to achieve some advanced usage.
function generator($start) { return function() use(&$start) { $start++; return $start; }; } $next = generator(0); echo $next(); // 输出 1 echo $next(); // 输出 2
- Functional programming in Haskell
Haskell is a purely functional programming language, and its functional programming support is far more complete and complex than PHP. This section will introduce some functional programming techniques in Haskell.
2.1 Higher-order functions
In Haskell, functions are first-class citizens, which means that functions can be passed and calculated like other values. Therefore, higher-order functions are also a major feature in Haskell.
apply :: (a -> b) -> a -> b apply f x = f x addThree :: Int -> Int addThree x = x + 3 main :: IO () main = do let res = apply addThree 5 putStrLn $ show res
2.2 Currying
Currying is a technique that converts a multi-parameter function into a function with only a single parameter. In Haskell, all functions have only one parameter. If multiple parameters are required, currying is required.
add :: Int -> Int -> Int add x y = x + y addCurry :: Int -> (Int -> Int) addCurry x = (y -> x + y) main :: IO () main = do let res1 = add 2 3 res2 = (addCurry 2) 3 putStrLn $ show res1 putStrLn $ show res2
2.3 Function synthesis
Haskell often links multiple functions together to form a new function through function synthesis. Function composition improves code readability and allows us to use less code to accomplish the same task.
compose :: (b -> c) -> (a -> b) -> a -> c compose f g x = f (g x) addThree :: Int -> Int addThree x = x + 3 double :: Int -> Int double x = x * 2 main :: IO () main = do let res = compose addThree double 2 putStrLn $ show res
- Summary
This article introduces some basic skills of functional programming in PHP and Haskell, allowing readers to understand how to use these two programming languages for functional programming. . Whether you are a PHP developer or a Haskell developer, you can learn some useful knowledge from this article. Functional programming is a trend, and good use of functional programming can effectively improve code quality and readability.
The above is the detailed content of Functional programming with PHP and Haskell. For more information, please follow other related articles on the PHP Chinese website!

Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Hot Topics











JWT is an open standard based on JSON, used to securely transmit information between parties, mainly for identity authentication and information exchange. 1. JWT consists of three parts: Header, Payload and Signature. 2. The working principle of JWT includes three steps: generating JWT, verifying JWT and parsing Payload. 3. When using JWT for authentication in PHP, JWT can be generated and verified, and user role and permission information can be included in advanced usage. 4. Common errors include signature verification failure, token expiration, and payload oversized. Debugging skills include using debugging tools and logging. 5. Performance optimization and best practices include using appropriate signature algorithms, setting validity periods reasonably,

Static binding (static::) implements late static binding (LSB) in PHP, allowing calling classes to be referenced in static contexts rather than defining classes. 1) The parsing process is performed at runtime, 2) Look up the call class in the inheritance relationship, 3) It may bring performance overhead.

A string is a sequence of characters, including letters, numbers, and symbols. This tutorial will learn how to calculate the number of vowels in a given string in PHP using different methods. The vowels in English are a, e, i, o, u, and they can be uppercase or lowercase. What is a vowel? Vowels are alphabetic characters that represent a specific pronunciation. There are five vowels in English, including uppercase and lowercase: a, e, i, o, u Example 1 Input: String = "Tutorialspoint" Output: 6 explain The vowels in the string "Tutorialspoint" are u, o, i, a, o, i. There are 6 yuan in total

What are the magic methods of PHP? PHP's magic methods include: 1.\_\_construct, used to initialize objects; 2.\_\_destruct, used to clean up resources; 3.\_\_call, handle non-existent method calls; 4.\_\_get, implement dynamic attribute access; 5.\_\_set, implement dynamic attribute settings. These methods are automatically called in certain situations, improving code flexibility and efficiency.

PHP and Python each have their own advantages, and choose according to project requirements. 1.PHP is suitable for web development, especially for rapid development and maintenance of websites. 2. Python is suitable for data science, machine learning and artificial intelligence, with concise syntax and suitable for beginners.

PHP is widely used in e-commerce, content management systems and API development. 1) E-commerce: used for shopping cart function and payment processing. 2) Content management system: used for dynamic content generation and user management. 3) API development: used for RESTful API development and API security. Through performance optimization and best practices, the efficiency and maintainability of PHP applications are improved.

PHP is a scripting language widely used on the server side, especially suitable for web development. 1.PHP can embed HTML, process HTTP requests and responses, and supports a variety of databases. 2.PHP is used to generate dynamic web content, process form data, access databases, etc., with strong community support and open source resources. 3. PHP is an interpreted language, and the execution process includes lexical analysis, grammatical analysis, compilation and execution. 4.PHP can be combined with MySQL for advanced applications such as user registration systems. 5. When debugging PHP, you can use functions such as error_reporting() and var_dump(). 6. Optimize PHP code to use caching mechanisms, optimize database queries and use built-in functions. 7

PHP is still dynamic and still occupies an important position in the field of modern programming. 1) PHP's simplicity and powerful community support make it widely used in web development; 2) Its flexibility and stability make it outstanding in handling web forms, database operations and file processing; 3) PHP is constantly evolving and optimizing, suitable for beginners and experienced developers.
