Попросил сделать monad tutorial
К слову, это не "просто туториал", а по моему "проекту". Не идеально, и обработка ошибок скорее запутывает, но на фоне туториалов написанных "мешками" конкурентоспособно:
Promises in JavaScript encapsulate asynchronous operations, allowing you to chain them together and handle their results in a clean, composable manner. The async/await notation simplifies working with Promises even further by providing a more synchronous-looking syntax for managing asynchronous code.
Monads in Haskell are a more general abstraction that can be used to express various types of computations in a clean and composable manner, including those that involve side effects like asynchronous operations.
To draw a parallel between Promises and monads, let's consider the following points:
1. Chaining operations: Both Promises and monads allow for chaining operations together. In JavaScript, you chain Promises using then. In Haskell, you can chain monadic computations using the >>= (bind) operator or the do notation.
2. Error handling: Promises in JavaScript handle errors via the catch method, allowing you to handle them in a centralized manner. In Haskell, the Either monad can be used to represent computations that may fail, and the monadic operations allow you to handle errors in a similar way.
Now let's consider the async/await notation in JavaScript and how it relates to monads in Haskell.
The async/await notation allows you to write asynchronous code that looks similar to synchronous code. In Haskell, you can achieve a similar effect using the do notation, which provides a more "imperative" syntax for chaining monadic computations.
To demonstrate this, let's consider an example using the IO monad in Haskell, which can be used to represent asynchronous operations:
import Control.Concurrent.Async
fetchData :: IO String
fetchData = ...
fetchMoreData :: String -> IO String
fetchMoreData input = ...
main :: IO ()
main = do
asyncHandle <- async fetchData
result1 <- wait asyncHandle
result2 <- fetchMoreData result1
putStrLn result2This example demonstrates how you can use the IO monad to represent asynchronous operations, and the do notation to chain them together, similar to how you would use async/await in JavaScript.
In summary, monads in Haskell are a more general abstraction that can be used to express various types of computations, including those that involve side effects like asynchronous operations. Promises and the async/await notation in JavaScript can be seen as a specific instance of this abstraction, tailored to the needs of the JavaScript language and ecosystem. By understanding the similarities between these concepts, you can leverage your knowledge of Promises and async/await to better understand monads and their applications in Haskell.
Promises in JavaScript encapsulate asynchronous operations, allowing you to chain them together and handle their results in a clean, composable manner. The async/await notation simplifies working with Promises even further by providing a more synchronous-looking syntax for managing asynchronous code.
Monads in Haskell are a more general abstraction that can be used to express various types of computations in a clean and composable manner, including those that involve side effects like asynchronous operations.
To draw a parallel between Promises and monads, let's consider the following points:
1. Chaining operations: Both Promises and monads allow for chaining operations together. In JavaScript, you chain Promises using then. In Haskell, you can chain monadic computations using the >>= (bind) operator or the do notation.
2. Error handling: Promises in JavaScript handle errors via the catch method, allowing you to handle them in a centralized manner. In Haskell, the Either monad can be used to represent computations that may fail, and the monadic operations allow you to handle errors in a similar way.
Now let's consider the async/await notation in JavaScript and how it relates to monads in Haskell.
The async/await notation allows you to write asynchronous code that looks similar to synchronous code. In Haskell, you can achieve a similar effect using the do notation, which provides a more "imperative" syntax for chaining monadic computations.
To demonstrate this, let's consider an example using the IO monad in Haskell, which can be used to represent asynchronous operations:
import Control.Concurrent.Async
fetchData :: IO String
fetchData = ...
fetchMoreData :: String -> IO String
fetchMoreData input = ...
main :: IO ()
main = do
asyncHandle <- async fetchData
result1 <- wait asyncHandle
result2 <- fetchMoreData result1
putStrLn result2This example demonstrates how you can use the IO monad to represent asynchronous operations, and the do notation to chain them together, similar to how you would use async/await in JavaScript.
In summary, monads in Haskell are a more general abstraction that can be used to express various types of computations, including those that involve side effects like asynchronous operations. Promises and the async/await notation in JavaScript can be seen as a specific instance of this abstraction, tailored to the needs of the JavaScript language and ecosystem. By understanding the similarities between these concepts, you can leverage your knowledge of Promises and async/await to better understand monads and their applications in Haskell.