50 Matching Annotations
  1. Mar 2021
    1. Put another way, it’s become clear to me over time that the problems with data races and memory safety arise when you have both aliasing and mutability. The functional approach to solving this problem is to remove mutability. Rust’s approach would be to remove aliasing. This gives us a story to tell and helps to set us apart. A note on terminology: I think we should refer to aliasing as sharing. In the past, we’ve avoided this because of its multithreaded connotations. However, if/when we implement the data parallelism plans I have proposed, then this connotation is not at all inappropriate. In fact, given the close relationship between memory safety and data races, I actually want to promote this connotation.
  2. Feb 2021
    1. The latter are important examples which usually also exist in "purely" functional programming languages.

      How can they exist and it still be considered pure??

      I guess that's not quite the same / as bad as saying something had side effects in a purely functional programming context, right?

    1. So every program starts in the IO monad. From here you can get any input you need, call into relatively "pure" code with the inputs, and then output the result in some way. The reverse does not work. You cannot call into IO code from pure code like you can call into a Maybe function from pure code.
    1. Purely functional programming may also be defined by forbidding state changes and mutable data.
    2. purely functional programming usually designates a programming paradigm—a style of building the structure and elements of computer programs—that treats all computation as the evaluation of mathematical functions.
    3. Purely functional data structures are persistent. Persistency is required for functional programming; without it, the same computation could return different results.
    1. Whatever language or default programming paradigm a developer uses, following the monad pattern brings many of the benefits of purely functional programming.
    2. To emphasize how Just acts on the underlying value by wrapping it, it can be redefined as a function too, called eta for now
    3. Research beginning in the late 1980s and early 1990s established that monads could bring seemingly disparate computer-science problems under a unified, functional model.
    1. The central ideas of this design pattern closely mirror the semantics of first-class functions and higher-order functions in functional programming languages. Specifically, the invoker object is a higher-order function of which the command object is a first-class argument.
    1. “Functional programming language” is not a clearly defined term. From the various properties that are typically associated with functional programming I only want to focus on one: “Immutability” and referential transparency.

      I mean not clearly defined seems wrong, there are common accepted characteristics that make a language functional.

  3. Jan 2021
    1. The changes we needed to make to main to reassign post mean that this implementation doesn’t quite follow the object-oriented state pattern anymore: the transformations between the states are no longer encapsulated entirely within the Post implementation. However, our gain is that invalid states are now impossible because of the type system and the type checking that happens at compile time! This ensures that certain bugs, such as display of the content of an unpublished post, will be discovered before they make it to production.

      This is really an amazing chapter for comparing (some aspects) of object oriented and functional programming, and I have to admit I still prefer the functional approach as a default.

    1. { item1: "hello", item2: "world" }

      Valida in automatico l'oggetto passato con l'interfaccia?

      Non necessità di un'istanza o di specificare l'interfaccia dell'istanza?

      Interessante..

  4. Dec 2020
    1. Note: The examples in Listings 10-17, 10-18, and 10-24 declare variables without giving them an initial value, so the variable name exists in the outer scope. At first glance, this might appear to be in conflict with Rust’s having no null values. However, if we try to use a variable before giving it a value, we’ll get a compile-time error, which shows that Rust indeed does not allow null values.
    1. My frustration is mainly from Svelte's choices that are very un-JavaScript-like. It doesn't have to be "like React/Vue". React is React because it doesn't restrict what you can do with JavaScript for the most part. It's just common FP practice to fold/map.
  5. Oct 2020
    1. In practice, functional programming is all about hiding for loops, which are abstracted away by the mapper functions that automate the iteration.
    1. The lodash/fp module promotes a more functional programming (FP) friendly style by exporting an instance of lodash with its methods wrapped to produce immutable auto-curried iteratee-first data-last methods.
    1. All validators can be used independently. Inspried by functional programming paradigm, all built in validators are just functions.

      I'm glad you can use it independently like:

      FormValidation.validators.creditCard().validate({
      

      because sometimes you don't have a formElement available like in their "main" (?) API examples:

      FormValidation.formValidation(formElement
      
  6. Sep 2020
    1. It turns out that even the length of time an element has been mounted is an important piece of state that determines what pixels the user sees. And some of this state can’t simply be lifted into our application state.

      What this means is that our desire to express UI using pure functions is in direct conflict with the very nature of the DOM. It’s a great way to describe a state => pixels transformation — perfect for game rendering or generative art — but when we’re building apps on the web, the idea chafes against the reality of a stateful medium.

    2. Functions have lots of interesting and useful properties. You can isolate them. You can compose them. You can memoize them. In other words, functional UI feels correct, and powerful, in a way that wasn’t true of whatever came before it. I think this is why people get quasi-religious about React. It’s not that it’s Just JavaScript. It’s that it’s Just Functions. It’s profound.

    1. A paradigm is a model or pattern. In JavaScript, there are a number of popular paradigms including object-oriented programming (OOP) and functional programming (FP). Paradigms are more important than is sometimes recognized. They help form mental models for solving problems. Becoming well-versed in the principles of a given paradigm can help accelerate development by providing mental shortcuts for solving the challenges that arise while building applications. They can also help produce higher quality software.
    1. We wanted a library designed specifically for a functional programming style, one that makes it easy to create functional pipelines, one that never mutates user data.
  7. Apr 2020
  8. Feb 2020
    1. Nix is a purely functional package manager. This means that it treats packages like values in purely functional programming languages such as Haskell — they are built by functions that don’t have side-effects, and they never change after they have been built.
  9. Jan 2020
  10. Nov 2019
    1. We might have some dirty mutable objects for performance - but our high-level API should be purely functional. You should be able to follow the React model of modelling your UI as a pure function of application state -> UI.
    1. the abstraction I wished to have was a sort of a pure functional Vim, completely decoupled from terminal UI - where 'vim' is a function of (editor state, input) => (new editor state)
  11. Jan 2019
    1. after the terminal operation of the stream pipeline commences.

      Above is because of the nature of Streams in general: they are lazily executed (or put another way, execution is delayed until the latest convenient method call).

  12. Nov 2018
    1. That is using a specific tool for a specific use case. You don’t actually have a table view of your data. Once it’s in a table, man, you’re good. That is the modeling. A sequel database table, you have this amazing high-level language for doing all sorts of cool operations with it.To turn this into some class hierarchy, it’s almost criminal. There, I said it. It’s like you’re throwing away the power that you have.

      about a situation when you sometime want an is-a relationship but in most cases just have it as loosely structured (table-like) data format

  13. Sep 2018
  14. Aug 2018
  15. Apr 2018
    1. (== 10)

      This confused me. I'm relatively new to Haskell and did not know about sectioning. After learning that detail, this makes sense as a (right) partial application of the (==) function.

  16. Aug 2017
    1. Since Clojure uses the Java calling conventions, it cannot, and does not, make the same tail call optimization guarantees. Instead, it provides the recur special operator, which does constant-space recursive looping by rebinding and jumping to the nearest enclosing loop or function frame. While not as general as tail-call-optimization, it allows most of the same elegant constructs, and offers the advantage of checking that calls to recur can only happen in a tail position.

      Clojure's answer to the JVM's lack to tail call optimization

  17. Apr 2016
  18. Jul 2015
    1. Keeping unpure functions clearly named and organized in such a way that they can be easily identified versus pure functions is a common goal of modularizing and organizing Scala applications.
    2. Much like a Unix power user will compose multiple single-purpose tools into a complex piped command, a functional programmer will combine single-purpose function invocations into chains of operations (think Map/Reduce).