Goswin Rothenthal goswinr

An interview with Crews, formerly known as Fast F#.

Q: What can you say about how you discovered Odin, and what appealed to you about it?

A: First off, it's an honor to be interviewed for the newsletter and thank you for inviting me! Scheduling and Planning Optimization have been my obsession since I can remember. There's actually a joke in my family that I've been doing it since before I was born. My mom was working on her PhD when she was pregnant with me and was taking classes on Operations Research, the science of planning and scheduling, so I've been exposed to this area of work since before I was born. For context, I don't see myself as a developer. Professionaly, I started life as a Chemical Engineer and then moved to Industrial Engineering when I saw that the main problems faced by companies are planning and scheduling. Learning to write code was just a by product of wanting to solve these problems. This means I am language agnostic. I really don't care what language people use.

I think you ne

Simple physics in F# and WPF

This is an example on how to use WPF and F# to do some simple physics using Verlet Integration.

The program creates a system of particles and constraints. Particles have inertia and is affected by gravity but their motion is also contrained by the constraints.

I tried to annotate the source code to help guide a developer familiar with languages like C#. If you have suggestions for how to improve it please leave a comment below.

How to run

Parsers combinators with F#6 `[<InlineIfLambda>]`

Thanks to manofstick peer reviewing the blog post.

Full source code at github

For F# Advent 2021 I wrote a blog post exploring how F#6 [<InlineIfLambda>] can improve data pipeline performance.

I was thinking of other places where [<InlineIfLambda>] can help and decided to try to build a parser combinator library with [<InlineIfLambda>].

Fsharp goodies (Vol 1)

After the 'F# Compiler Community Session' I read the first 1K lines of SyntaxTree.fs. That's what I learned about the language.

There is a byte string

let a = "abc"B
val a : byte [] = [|97uy; 98uy; 99uy|]

Architecture

Use Onion architecture
- Dependencies go inwards. That is, the Core domain doesn't know about outside layers
Use pipeline model to implement workflows/use-cases/stories
- Business logic makes decisions
- IO does storage with minimal logic
- Keep Business logic and IO separate
Keep IO at edges

	open BenchmarkDotNet.Attributes
	open BenchmarkDotNet.Configs
	open BenchmarkDotNet.Environments
	open BenchmarkDotNet.Jobs
	open BenchmarkDotNet.Running

	[<MemoryDiagnoser(displayGenColumns=false)>]
	[<HideColumns("Job", "Error", "StdDev", "Median", "RatioSD")>]
	type Benchmarks () =
	let x = Some 3

	module rec Dat

	open Browser.Types
	open Fable.Core
	open System

	[<ImportAll("dat.gui")>]
	let exports: IExports = jsNative

	[<AllowNullLiteral>]

	(*
	An immutable R-Tree implementation in F#.

	Based on: https://github.com/swimos/swim-rust/tree/main/swim_utilities/swim_rtree (licensed on Apache 2.0)

	Author: Bartosz Sypytkowski <b.sypytkowski at gmail.com>
	*)

	namespace Demos.RTree

	<aside class="relative bg-blue-700 lg:self-stretch lg:w-64 w-full shadow-xl flex flex-col">
	<div class="p-6 flex justify-between">
	<a href="..">
	<img class="object-scale-down h-8 lg:h-32" src=".." alt=".. Logo"/>
	</a>
	<div class="block lg:hidden">
	<button id="nav-toggle" class="flex items-center px-3 py-2 border rounded text-white border-white">
	<svg class="fill-current h-3 w-3" viewBox="0 0 20 20" xmlns="http://www.w3.org/2000/svg">
	<title>Menu</title>
	<path d="M0 3h20v2H0V3zm0 6h20v2H0V9zm0 6h20v2H0v-2z"/>

	open SharedMemory
	open MBrace.FsPickler

	module Rpc =
	type RpcContext<'command, 'message> =
	{ name: string; buffer: RpcBuffer; post: 'command -> Async<'message>} with
	interface IDisposable with
	member this.Dispose() = this.buffer.Dispose()

	let createHost name (handler : 'command -> Async<'message>) =