antonio nikishaev llelf

Предстоящие события

2023-09-26 Казань. Митап по функциональному программированию в Казани Регистрация

Темы:

— про software transactional memory (STM) и том, какие проблемы она решает;

— как работать с иммутабельными данными удобно и без боли.

Introduction

I was recently asked to explain why I felt disappointed by Haskell, as a language. And, well. Crucified for crucified, I might as well criticise Haskell publicly.

First though, I need to make it explicit that I claim no particular skill with the language - I will in fact vehemently (and convincingly!) argue that I'm a terrible Haskell programmer. And what I'm about to explain is not meant as The Truth, but my current understanding, potentially flawed, incomplete, or flat out incorrect. I welcome any attempt at proving me wrong, because when I dislike something that so many clever people worship, it's usually because I missed an important detail.

Another important point is that this is not meant to convey the idea that Haskell is a bad language. I do feel, however, that the vocal, and sometimes aggressive, reverence in which it's held might lead people to have unreasonable expectations. It certainly was my case, and the reason I'm writing this.

Type classes

I love the concept of type class

Notes on privacy and data collection of Matrix.org

This version of the document is no longer canonical. You can find the canonical version hosted at Gitlab and Github.

PART 2 IS OUT, INCLUDING THE DISCLOSURE OF A GLOBAL FEDERATION DATA LEAK, AND THE ANATOMY OF A GDPR DATA REQUEST HANDLED BY MATRIX.ORG. SEE THE REPOS ABOVE.

Official site (kparc.com)

Summary
Example programs
Updated (?) edit.k
~2014 older version that has more info
The project has been running since at least 2012

	foldRight' ::
	(b -> z -> z)
	-> (a -> b)
	-> z
	-> [a]
	-> z
	foldRight' _ _ z [] =
	z
	foldRight' k f z (x:xs) =
	k (f x) (foldRight' k f z xs)

	Set Implicit Arguments.
	Set Contextual Implicit.

	Record container : Type := {
	shape : Type;
	pos : shape -> Type;
	}.

	Inductive ext (c : container) (a : Type) : Type := {
	this_shape : shape c;

	Section from_ssrfun.

	Local Set Implicit Arguments.
	Local Unset Strict Implicit.
	Local Unset Printing Implicit Defensive.

	Variables S T R : Type.

	Definition left_inverse e inv (op : S -> T -> R) := forall x, op (inv x) x = e.

	{-\| This @lens@ tutorial targets Haskell beginners and assumes only basic
	familiarity with Haskell. By the end of this tutorial you should:

	* understand what problems the @lens@ library solves,

	* know when it is appropriate to use the @lens@ library,

	* be proficient in the most common @lens@ idioms,

	* understand the drawbacks of using lenses, and:

	-module(bit_vector).

	-export([new/1, get/2, set/2, clear/2, flip/2, print/1]).


	new(Size) ->
	Words = (Size + 63) div 64,
	{?MODULE, Size, atomics:new(Words, [{signed, false}])}.

	get({?MODULE, _Size, Aref}, Bix) ->