On the topic of compile times, Elm should be pretty fast!
I tried to gather some numbers on it in this repo. Notable data points include:
There are some outliers in the data, like this one, where certain files take longer for some reason. It seemed related to GC pauses (i.e. heap getting full) but I wasn’t able to figure out the root cause with that person without access to their code.
That said, I think the time is still quite good compared to other compilers. I definitely have slower Haskell builds with much fewer lines of code!
Anyway, I recommend looking through that repo to get an idea of the current situation. The general-case build times seem to be really good, but I wanted to figure out what was going on with the outliers before publishing something about it. Also, happy to talk with people who have outlier build times to figure out what is going on!
P.S. I have not heard of object files getting so big that they wouldn’t fit on the heap! Not til @rupert mentioned it here! I believe adding something like +RTS -H512m -RTS will let you change the initial heap size as he says though. More details on that here, and lots of other flags to try. Independently, I have some ideas on how to reduce the size of those files on disk and in the heap because that’ll make things faster in general, but I think it won’t be until 0.20 at least before I revisit that, which will probably be one or two years out.