Ask HN: What piece of code/codebase blew your mind when you saw it?

• Apollo-11

  127 56,371 4.6 Assembly

  Original Apollo 11 Guidance Computer (AGC) source code for the command and lunar modules.

https://github.com/chrislgarry/Apollo-11/blob/a13539c7c5c482...

My mind was blown that I could read Apollo 11 source code. It was additionally blown that it included comments like, "# TEMPORARY, I HOPE HOPE HOPE"

• astexplorer

  43 5,932 6.3 JavaScript

  A web tool to explore the ASTs generated by various parsers.

it isn't rocket science, but https://github.com/fkling/astexplorer significantly raised my standard of what a readable, modifiable, nontrivial react/redux codebase could look like. bonus that astexplorer is basically used by everyone in the js tooling ecosystem

• InfluxDB

  www.influxdata.com sponsored

  Power Real-Time Data Analytics at Scale. Get real-time insights from all types of time series data with InfluxDB. Ingest, query, and analyze billions of data points in real-time with unbounded cardinality.

  

• .NET Runtime

  607 14,091 10.0 C#

  .NET is a cross-platform runtime for cloud, mobile, desktop, and IoT apps.

  

Well, .NET's garbage collector certainly springs to mind. Not exactly in a good way. You know you have something special on your hands when GitHub refuses to show you a highlighted version of a hand written C++ file (https://github.com/dotnet/runtime/blob/main/src/coreclr/gc/g...).

Other than that, I remember my mind was blown a few times while watching Jim Weirich's presentation on functional programming all those years ago (https://www.youtube.com/watch?v=FITJMJjASUs).

• pygments

  2 1,702 9.4 Python

  Pygments is a generic syntax highlighter written in Python

  

Its been a while since I worked with this lib but I always thought Pygments was pretty.

https://github.com/pygments/pygments

• ioccc-obfuscated-c-contest

  87 130 0.0 HTML

  IOCCC International Obfuscated C code contest entries

IOCCC taught me that form is just as important as function, and often a lot more fun: https://www.ioccc.org/

• cosmopolitan

  201 15,067 9.8 C

  build-once run-anywhere c library

• quine-relay

  49 13,756 6.4 Ruby

  An uroboros program with 100+ programming languages

• WorkOS

  workos.com sponsored

  The modern identity platform for B2B SaaS. The APIs are flexible and easy-to-use, supporting authentication, user identity, and complex enterprise features like SSO and SCIM provisioning.

  

• Quake-2

  12 2,671 0.0 C

  Quake 2 GPL Source Release

  

• Idris2

  39 2,395 9.6 Idris

  A purely functional programming language with first class types

  

The Idris codebase is quite beautiful. Given some understanding of how it works underneath, I find that there’s a succinct clarity in everything.

https://github.com/idris-lang/Idris2

• mal

  94 9,803 0.0 Assembly

  mal - Make a Lisp

For me it was the "Make a Lisp" project. Reading the architectural diagram of a Lisp interpreter, and browsing its implementation in many (87) programming languages.

https://github.com/kanaka/mal

Especially where the guide explains how tail-call optimization works, my mind was blown.

https://github.com/kanaka/mal/blob/master/process/guide.md#s...

Studying the project changed the way I understand code. Since then I've created my own little Lisps in about three or four versions/languages. Next I'd like to write one in WebAssembly Text format, which is already in a Lisp-shaped syntax.

• protoactor-dotnet

  4 1,661 8.1 C#

  Proto Actor - Ultra fast distributed actors for Go, C# and Java/Kotlin

  

• notcurses

  102 3,281 7.6 C

  blingful character graphics/TUI library. definitely not curses.

notcurses: https://github.com/dankamongmen/notcurses

The guy is a literal genius, I hope to forget half the stuff he knows.

Also Fabrice Bellard (ffmpeg/qemu).

• primes-cpp

  1 0 10.0 C++

  A compact primes library containing a highly optimized prime sieve and deterministic primality test.

Everybody mentions this, and what's great is that it is a pretty natural solution to a lot of problems. I remember coming up with a version of it while writing an optimized prime-sieve[1], and was surprised when I later learned that it was some named technique.

In addition to just the basic loop-unrolling (which I'm pretty sure you usually don't need to do by hand with modern compilers), it works really well when you need to jump into the middle of a pattern. Like if you're sieving primes in a wheel-factorized array.

[1] https://github.com/patricksjackson/primes-cpp/blob/master/pr...

  // Here we're only checking possible primes after wheel-factorization

• scheme

  5 165 1.5 WebAssembly

  An R7RS Scheme implemented in WebAssembly

• learnhaskell

  7 7,904 0.9 Makefile

  Learn Haskell

https://github.com/bitemyapp/learnhaskell/blob/master/dialog...

> a transducer is recognizing that the signature of foldl splits

> type Transducer a b = forall r. (r -> b -> r) -> (r -> a -> r)

> they compose like lenses

• lisp-in-life

  6 444 1.8 C

  A Lisp interpreter implemented in Conway's Game of Life

Almost forgot - Lisp In Life. Pretty sure I first saw that on HN. IMO the more amazing thing is the Life-based processor, once you have that, the rest is a matter of adding layers. But it's one thing to know someone could do it, quite another to see it in action.

https://github.com/woodrush/lisp-in-life

Run it in your browser here. Definitely worth zooming all the way in to get a sense of scale.

https://woodrush.github.io/lisp-in-life/

• SaaSHub

  www.saashub.com sponsored

  SaaSHub - Software Alternatives and Reviews. SaaSHub helps you find the best software and product alternatives

  

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