Mårten Rånge mrange

[F#/OCaml] Implementing a data streams library using a bunch of one-liners

A few years ago when I read the presentation motivating the design behind Nessos Streams I was struck by the beauty of simplistic push streams.

type PushStream<'T> = ('T -> bool) -> bool

LINQ (in .NET) is a pull stream, ie we pull values out of the stream by calling MoveNext + Current. One of the problems with pull streams is the constant checking "Are we done?" at each level in the stream.

[F#] Implementing Coroutines (async/await) using continuations

Coroutines or async/await is not a new concept as it was named in 1958 by Melvin Conway. Coroutines had support in languages such as Simula(1962), Smalltalk(1972) and Modula-2(1978) but I think one can argue that coroutines came into mainstream with C# 5(2012) when Microsoft added async/await to C#.

The problem with subroutines

A thread can only execute a single subroutine at a time as a subroutine starts and then runs to completion. In a server environment subroutines can be problematic as in order to service connections concurrently we would usually would start a thread per connection, this was the idiom a few years ago. A thread depending on the operating system and settings needs about 1 MiB of user stack space meaning 1,024 threads needs 1 GiB of for just user stack space. In addition there's the cost of kernel stack space, book-keeping and scheduling of threads. This drives cost of VM/hardwa

Paying It F#rward

This article is an entry in the 2019 F# Advent Calendar in English. Thanks to Sergey Tihon for organizing it, as always!

Note: This belongs on my blog, but some things are broken there right now, probably due to changes to GitHub Pages in recent years, so I'm publishing this here for now to at least get a reliable output.

The F# community, while small compared to those of many other languages, is known to be exceedingly open and helpful to beginners. I experienced this myself when I started learning the language nearly six years ago, and people (especially the F# MVPs) were always quick and eager to answer my newbie questions on Twitter, or wrote extensive answers on Stack Overflow or Code Review. Havi

F# Advent 2020, Dec 6 - Church Encoded Lists

Introduction

The purpose of abstraction is not to be vague, but to create a new semantic level in which one can be absolutely precise

Edsger W. Dijkstra

This is my contribution to F# Advent Calendar in English. Thanks to Sergey Tihon for making sure this happens every year.

F# Advent 2021 Dec 08 - Fast data pipelines with F#6

Thanks to Sergey Tihon for running F# Weekly and F# Advent.

Thanks to manofstick for trying out the code and coming with invaluable feedback. Cistern.ValueLinq is very impressive.

TLDR; F#6 enables data pipelines with up to 15x less overhead than LINQ

There were many interesting improvements in F#6 but one in particular caught my eye, the attribute InlineIfLambda.

Install shader

Save happy.hlsl to disk, note the path for later.
Open Windows terminal settings
Open settings as JSON
Add a custom shader to the default profile, see excerpt below.

{
 "profiles": {

FAQ on the xz-utils backdoor (CVE-2024-3094)

This is a living document. Everything in this document is made in good faith of being accurate, but like I just said; we don't yet know everything about what's going on.

Update: I've disabled comments as of 2025-01-26 to avoid everyone having notifications for something a year on if someone wants to suggest a correction. Folks are free to email to suggest corrections still, of course.

	#include <stdint.h>
	#include <stdlib.h>
	#include <stdbool.h>
	#include <windows.h>
	#pragma comment( lib, "user32.lib" )
	#pragma comment( lib, "gdi32.lib" )

	#define SCRW 640
	#define SCRH 480