Sidekick

Build canisters in Haskell. Save code forever. Compile and run in the browser.

Are you judging me?

I wove a sort of story which hopefully makes evaluating this entry more fun:

1. Visit the canister URL and follow the link for the judges.

2. Try to push all crates to target squares. It’s Sokoban!

3. Press Q or Escape to quit. Surprise! We’re actually in a game editor. Here you can change the graphics, the levels, and the rules, and also save your work, which persists on a canister on the IC.

4. Click the link to Sidekick, login with "demo". This time it’s a Haskell compiler, and again you can edit code which persists. Click "Run" to compile and run programs in the browser.

5. But there’s more! Lower down the page is a "Download wasm canister" button. With suitable foreign export declarations, clicking this button produces a wasm canister that can be deployed on the Internet Computer. Follow the instructions to see it in action.

In fact, the canister which holds the PuzzleScript games was built using this app. It’s the "persist map" example.

Navigate to /rps for another canister built by Sidekick.

This entry might count as an SDK, but it also includes:

• Sokoban-style puzzle maker.

• Massively multiplayer rock-paper-scissors.

• Candid buffer decoder with annotations.

• Drawing the mandelbrot set with 16-bit integer arithmetic.

• Enigma machine simulation.

• Arbitrary precision arithmetic library.

• …​explore to find more!

How to build

Assuming git wget make time are installed:

$ apt install clang lld gperf asciidoctor
$ ./mkall

To build the puzzle store, follow the instructions for building a canister from the "persist map" example. Change the canister ID in judge.txt to match, and rebuild the Sidekick canister with:

$ ./mkui && ./mkwasm

Follow similar steps to build the Rock Paper Scissors demo.

It remains to seed the puzzle store canister with preset examples. The coldopen directory contains the AsciiDoc source of a webpage. Build this webpage (asciidoctor puzzlepusher.txt), load it in a browser, and click "Go".

Notes

I’m playing DFINIHack on Hard Mode:

• solo team

• no Motoko

• no Rust

• no npm; in fact, no JS libraries

• no GHC

• C allowed, but nothing beyond stdio and stdlib

These constraints forced me to roll my own IC agent and encoders and decoders for Candid, CBOR, and even wasm. Thankfully I could draw on past work:

• Internet Computer experiments

• a Haskell compiler

• a PuzzleScript clone