# learning introduction — RSS Amplifier Recent posts from the 3 feeds in the RSS Amplifier directory that cover learning introduction. Page: Feed: --- ## [Lox as a Racket language module](https://davidelettieri.it/2026/04/06/lox-as-a-racket-language-module) _2026-04-06 · Davide Lettieri Blog_ For a long time, I wanted to implement a Racket language module with a non-lispy surface syntax. Lox, from Crafting Interpreters, was an obvious candidate: I didn't want to invent a new syntax nor new semantics and I already ported the project to C#. In this case, my main objective was to leverage Racket language-building facilities while learning Racket, Scheme, and macros. ## [Extensible Visitor Pattern in C#](https://davidelettieri.it/2025/11/26/extensible-visitor-pattern) _2025-11-15 · Davide Lettieri Blog_ Recently, I stumbled upon this paper Synthesizing Object-Oriented and Functional Design to Promote Re-Use. The paper wants to provide a solution to the expression problem. The authors suggest an improved version of the visitor pattern that they call "extensible visitor pattern" which is essentially a combination of the visitor pattern with the factory method pattern. ## [Sutton & Barto Gridworld example in C#](https://davidelettieri.it/2025/10/19/sutton-barto-gridworld) _2025-10-19 · Davide Lettieri Blog_ Lately, I've been exploring various examples from Sutton and Barto's "Reinforcement Learning ## [Webhooks packages to simplify payload signing](https://davidelettieri.it/2025/09/21/webhooks-packages) _2025-09-21 · Davide Lettieri Blog_ A few weeks back I became aware of an attempt to create a technology agnostic standard to send and receive webhooks securely. The proposal is here. ## [Announcing the new comment system](https://davidelettieri.it/2025/08/18/comments-announcement) _2025-08-18 · Davide Lettieri Blog_ After thinking about it for some time I decided to add a comment system to the blog. What I hope is that I will get valuable feedback from readers, which will help me improve the content, my understanding of the topics I write about, and the overall quality of the blog. ## [Ray tracing in one weekend in go](https://davidelettieri.it/2025/06/16/ray-tracing-in-one-weekend) _2025-06-16 · Davide Lettieri Blog_ I had the Ray Tracing in One Weekend book in my todo list for a long time and I had finally the time to go through it. ## [Multi armed bandit exercise 2.5 with C#](https://davidelettieri.it/2025/05/01/multi-armed-bandit-ex-2.5-csharp) _2025-05-01 · Davide Lettieri Blog_ Recently I tried to code the 10 armed testbed example from chapter 2 of Sutton and Barto Reinforcement Learning: an introduction book. ## [Ten armed testbed for the Bandit problem with C#](https://davidelettieri.it/2025/04/27/ten-armed-testbed-with-c-sharp) _2025-04-27 · Davide Lettieri Blog_ I'm continuing my attempt to reproduce examples from Reinforcement Learning: An Introduction book using C#. ## [CSV parsing with typescript](https://davidelettieri.it/2025/04/10/csv-parsing-with-typescript) _2025-04-10 · Davide Lettieri Blog_ A few years ago I needed to troubleshoot some imports based on csv files and I had one big issue, depending on the language the user was using on Windows, Excel would export csv files with different separators. Being located in Italy, this means that the separator was ;. The same was true when trying to read csv with Excel, the separator is chosed based on the language of the OS. ## [Asynchronous request reply pattern without polling](https://davidelettieri.it/2025/04/02/asynchronous-request-reply-pattern) _2025-04-04 · Davide Lettieri Blog_ The asynchronous request reply pattern is useful in cases where an application has a client application running in a browser where the user starts an operation and is waiting for an immediate feedback and possibly a success notification. An issue arises only if the requested operation is long running, even a few seconds is unacceptable to return a feedback to a waiting user. Microsoft has a nice… ## [Brisk AI News Briefings (Sponsored)](https://crawlproof.com/a/Nmam78TQHNCY) _2025-04-03 · **Sponsored**_ Read AI summaries and listen to audio briefings for top stories. ## [Tic-tac-toe reinforcement learning with C#](https://davidelettieri.it/2025/03/16/tic-tac-toe-reinforcement-learning-with-c-sharp) _2025-03-16 · Davide Lettieri Blog_ A couple of weeks ago I wanted to take a look at reinforcement learning and possibly work on a very simple sample in C#. In search for a book to learn some basics I found Reinforcement Learning: An Introduction suggested in multiple places. The book is available for free as a PDF on the linked website, so I thought it would be a good starting point. ## [Kaleidoscope tutorial with C# using LLVMSharp and llvm 18](https://davidelettieri.it/2025/02/15/kaleidoscope-tutorial-llvmsharp-18) _2025-02-20 · Davide Lettieri Blog_ Since writing this, LLVMSharp had a new stable v20 release. The code in the repo is updated to this package. ## [Trying to implement Lox as Racket language module](https://davidelettieri.it/2025/01/18/trying-to-implement-lox-as-racket-language-module) _2025-01-18 · Davide Lettieri Blog_ Given my previous attempt of having a basic scaffolding for creating a new racket language, I thought it was worth a shot at implementing Lox from the Crafting interpreters book as a Racket language module.