Status of School of Haskell 2.0

Earlier this year, I wrote a blogpost about our plans

for the next version of the School of Haskell. SoH is a community

service and project to make it possible to use interactive snippets

of Haskell on any website, in particular on schoolofhaskell.com. Today,

we are open sourcing the SoH 2.0 repositories! We've also retired

FP Haskell Center, and SoH pages that were previously on fpcomplete.com now redirect to schoolofhaskell.com.

Here's the current status of the different parts:

Here's the repo main SoH code, which includes the browser client and API

service. Once the service side of things is ready, they will allow

you to embed interactive Haskell snippets in any website!

The soh-client

is written using GHCJS, and provides a code editing widget. It uses

ghcjs-react to

separate the view from the model / controller. It utilizes some of

GHCJS's fancier features, such as fully supporting concurrency and

STM.

The soh-runner runs within a container, and hooks up stack-ide to a websocket for communication with soh-client.

The soh-scheduler provides a REST API for requesting that a

container running soh-runner gets spun up. We ran into some issues

with deployment to ECS, likely due to our huge docker images. Our

plan is to rework / rewrite the service code to instead target

Kubernetes. Since the initial

implementation of SoH 2.0, we've had a lot of positive experiences

with kubernetes, and would prefer to use it.

The schoolofhaskell.com repo repo contains code based on code for the fpcomplete.com site. It is served from schoolofhaskell.com. The

contents of the site is not yet interactive, as the kubernetes

based version of soh-scheduler still needs to be written and

deployed.

Future Improvements

There are quite a few immediate things to work on in SoH, in

particular, the switch to kubernetes, and integrating the new

client with schoolofhaskell.com. Once

these things are resolved, there are also some interesting

possibilities. Ever since the client code was initially written, a

number of developments have occurred that it might leverage:

One such development is haskell-ide-engine,

a project to centralize our efforts on providing Haskell tools

(particularly those that use GHC), as a service to text editors and

IDEs. We'd like to focus our efforts in this direction on

haskell-ide-engine, rather than stack-ide. This means that in the

future, SoH may be based on haskell-ide-engine, along with some

selection of its plugins. I encourage people to dive into helping

with HIE, to bring it to a point where it makes Haskell development

excellent, and to make it fit for usage SoH 2.0.

Another interesting development is Ryan Trinkle's excellent reflex

library for reactive UI. While using react was quite nice overall,

I ended up hacking around some of the paradigm. I think things

would work out cleaner with reflex / reflex-dom, and this way SoH

development can benefit that project!