The Summer of Code 2013 is over, and here is what I have to say about it.
The project is live at http://paste.hskll.org. The source code can be found at http://github.com/co-dan/interactive-diagrams.
I would like to say that I do plan to continue working on the project (and on adjacent projects as well if possible).
Interactive diagrams is a pastebin and a set of libraries used for dynamically compiling, interpreting and rendering the results of user inputted code in a secure environment.
The user inputs some code and the app compiles and renders it. Graphical output alongside with code can be useful for sharing the experiments, teaching beginners an so on. If the users inputs a code that can not be rendered on the server (i.e.: a function), the app produces an HTML5/JS widget that runs the corresponding code.
The produced libraries can be used in 3rd party services/programs.
The pastebin is powered by Scotty and scotty-hastache, the access to PosgreSQL db is done via the excellent persistent library. The compilation is done using GHC and GHCJS inside the workers processes powered by the restricted-workers library.
You can read some my previous report on this project which is still pretty relevant.
I plan on updating the documents on the wiki sometime soon.
The bad news is that I don’t think I was able to 100% complete what I originally envisioned. The good news is that I seem to know, almost exactly, what do I want to improve and how to do that. As I’ve mentioned I plan on continuing with the project and I hope that the project will grow and improve.
One thing that I felt was annoying is the (technical) requirement to use GHC HEAD. Because of that a lot of packages required updates and fixes. Due to changes in GHC and bugfixes in GHCJS I had to perform the tiring and not so productive procedure of updating all the necessary tools, rebuilding everything and so on. But I guess that’s just how computers work and I am sure that in the future (with the release of GHC 7.8 and a new Haskell Platform) the maintenance and installation will be much easier. Another thing that took a lot of my time was configuring the system and setting up the necessary security measures, which was also necessary.
Other stuff that kinda slowed thing down include: the lack of a good build system, in some cases non-American timezone (actually I think that the fact that my mentor, Luite Stegeman, was quite close to me in terms of timezones allowed us to communicated very frequently, as we did), the lack of knowledge of the tools I used (although you can think of it this way: I had an ability to learn exciting new things ;] ).
Among the grand things I plan to do: release a library for manipulating Haskell AST at the GHC level; make an IRC bot using the eval-api and restricted-workers; continue writing my notes/tutorials about GHC API (I have a few drafts laying around).
Some code refactoring should come along and a number of features for the pastebin should be implemented.
When the end of the program was approaching I predicted that I would have that sort of conflicted feelings that you usually get when you finish reading a good book – one part of you feels happy because you had an enjoyable experience, yet another part of you doesn’t feel so giddy, because the thing that you enjoyed is over. Well, I didn’t get this with GSoC. I did feel happy, but I didn’t get this touch of sadness. GSoC was a way for me to get into collaborating with people on real-world open source projects, and the end of GSoC for me is a beginning of something else. I can use my experience now to write better code, write more code and write useful code.
I had a very exciting summer and I would positively recommend anyone eligible to participate in the Google Summer of Code program. There is, however, a thing to remember. Programmers are known to be the kind of people who set ambitious goals. Reach for something inspiring, ambitious, yet realistic. Make sure to find something in between, that way you’ll have a concrete target that you know that you are able to achieve, but you also have a room for improvement.
I would like to thank various people who helped me along the summer: Luite Stegeman, Brent Yorgey, Carter Schonwald, Daniel Bergey, Andrew Farmer; everyone in #diagrams, everyone in the #haskell channel who patiently answered my question; everyone on GitHub who responded to my comments, questions and pull requests. The Haskell community is lucky to have a huge amount of friendly and smart people.