In the past month I moved to Italy for a new Haskell job. Hopefully, we will be releasing some open source contributions.
I added about 25 more steps to Try Haskell and touched on types in Haskell, clickable code samples, lessons selection, go-back support, stricter expression checking, from the help of feedback from YCombinator, including Simon Pratt, who provided various patches to the jquery console with refactoring, fixing the history and adding standard console shortcuts.
I tidied up the JSON service code, removed redundant files, tided up module imports, made the mueval-core path not hard coded, etc. It is currently written with the FastCGI API. I have started a branch with the aim of switching it to Snap.
I have also added top-level binding support, e.g.:
> x = 1
> (y,z) = (5,6)
> x * y * z
=> 30
>
It works mostly in the same way GHCi does, with nested LET expressions. I think this way is sound. The bindings are per-session; they expire when you close your browser.
There is one change to the JSON service, when evaluating a top-level expression, the success return value is:
{"bind":"OK."}
Failure is returned as normal, e.g.
{"error":"Not in scope: `y"}
Another neat thing I added as suggested by tumult on YCombinator is support to link to a given expression, e.g.:
> map (*2) [1..1 0]
=> [2,4,6,8,10,12,14,16,18,20]
> link
link for map (*2) [1..10]
>
(The link for map (*2) [1..10] text is a link.)
I also re-enabled Raphael support for the hell of it.
I have more plans for it such as embedded code editor and smallcheck exercises, user-uploaded tutorials, and adding an embedded console to Hackage at some point would be nice, but that is all for now.
In other news, two other languages have started their own Try Lang sites! Check these out:
Raising awareness of all functional languages is a great thing!