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Having worked a bit in Zig, Rust, Go and now C, I think there are a few common topics worth having a fresh conversation on: automatic memory management, the standard library, and explicit allocation. Zig is not a mature language. But it has made enough useful choices for a number of companies to invest in it and run it in production. The useful choices make Zig worth talking about. Go and Rust are

I knew Zig supported some sort of reflection on types. But I had been confused about how to use it. What's the difference between @typeInfo and @TypeOf? I ignored this aspect of Zig until a problem came up at work where reflection made sense. The situation was parsing and storing parsed fields in a struct. Each field name that is parsed should match up to a struct field. This is a fairly common pr

As part of bringing myself up-to-speed after joining TigerBeetle, I wanted some background on how distributed consensus and replicated state machines protocols work. TigerBeetle uses Viewstamped Replication. But I wanted to understand all popular protocols and I decided to start with Raft. We'll implement two key components of Raft in this post (leader election and log replication). Around 1k line

For my second project while learning Zig, I decided to port an old, minimal SQL database project from Go to Zig. In this post, in ~1700 lines of code (yes, I'm sorry it's bigger than my usual), we'll create a basic embedded SQL database in Zig on top of RocksDB. Other than the RocksDB layer it will not use third-party libraries. The code for this project is available on GitHub. Here are a few exam

A minimal distributed key-value database with Hashicorp's Raft library When I wrote the "build a distributed PostgreSQL proof of concept" post I first had to figure out how to use Hashicorp's Raft implementation. There weren't any examples I could find in the Hashicorp repo itself. And the only example I could find was Philip O'Toole's hraftd. It's great! However, I have a hard time following mult

Writing a document database from scratch in Go: Lucene-like filters and indexes In this post we'll write a rudimentary document database from scratch in Go. In less than 500 lines of code we'll be able to support the following interactions, inspired by Elasticsearch: $ curl -X POST -H 'Content-Type: application/json' -d '{"name": "Kevin", "age": "45"}' http://localhost:8080/docs {"body":{"id":"5ac

SMTP protocol basics from scratch in Go: receiving email from Gmail I've never run my own mail server before. Before today I had no clue how email worked under the hood other than the very few times I've set up mail clients. I've heard no few times how hard it is to send mail from a self-hosted server (because of spam filters). But how hard can it be to hook up DNS to my personal server and receiv

Writing a minimal Lua implementation with a virtual machine from scratch in Rust By the end of this guide we'll have a minimal, working implementation of a small part of Lua from scratch. It will be able to run the following program (among others): function fib(n) if n < 2 then return n; end local n1 = fib(n-1); local n2 = fib(n-2); return n1 + n2; end print(fib(30)); This is my second project in

Enumerating and analyzing 40+ non-V8 JavaScript implementations V8 is, I'm sure, the most used implementation of JavaScript today. Used in Chrome, (and by extension) Microsoft Edge, Node.js, etc. Safari's JavaScriptCore and Firefox's SpiderMonkey are also contenders for extremely mainstream implementations. But what else is out there? What if I want to embed JavaScript in a C program, or a Go prog

Parser generators vs. handwritten parsers: surveying major language implementations in 2021 Developers often think parser generators are the sole legit way to build programming language frontends, possibly because compiler courses in university teach lex/yacc variants. But do any modern programming languages actually use parser generators anymore? To find out, this post presents a non-definitive s

Incredibly, Standard ML implementations are still actively developed. MLton, Poly/ML, MLKit, SML# and SML/NJ are the most prominent. Discussion on the future direction of Standard ML remains healthy as well. And somehow OCaml's lesser known cousin still beats out OCaml for multicore threading support (in Poly/ML). While MLton hasn't merged with MultiMLton or RTMLton to support multicore, a new for

Writing a SQL database from scratch in Go: 1. SELECT, INSERT, CREATE and a REPL Next in database basics: 2. binary expressions and WHERE filters 3. indexes 4. a database/sql driver In this series we'll write a rudimentary database from scratch in Go. Project source code is available on Github. In this first post we'll build enough of a parser to run some simple CREATE, INSERT, and SELECT queries.

After spending some time at work on tooling for keeping documentation in sync with Go struct definitions I had enough exposure to Go's built-in parsing package that next steps were clear: write an interpreter. It's a great way to get more comfortable with a language's AST. In this post we'll use the Go parser package to interpret the AST directly (as opposed to compiling to a bytecode VM) with eno

Writing a lisp compiler from scratch in JavaScript: 1. lisp to assembly Next in compiler basics: 2. user-defined functions and variables 3. LLVM 4. LLVM conditionals and compiling fibonacci 5. LLVM system calls 6. an x86 upgrade In this post we'll write a simple compiler in Javascript (on Node) without any third-party libraries. Our goal is to take an input program like (+ 1 (+ 2 3)) and produce a

It can be difficult to disassociate the idea that dynamically typed programming languages are tied to byte-code interpreters (e.g. YARV Ruby, CPython, V8, Zend Engine, etc.). But for many languages, a compiled implementation also exists. Cython, Chicken Scheme and SBCL are good examples. In this post I will briefly describe how I built a compiler for my Scheme implementation using artifacts from t