[Haskell-cafe] code-build-test cycle

Daniel Fischer daniel.is.fischer at web.de
Thu Sep 17 23:21:58 EDT 2009

Am Freitag 18 September 2009 04:42:32 schrieb Michael Mossey:
> I'm working on a GUI application in qtHaskell, and I have a bit of a bind.
> Using ghci, it launches quickly but runs slowly. On the other hand,
> compiling (mainly linking) takes a while---several minutes. The truth is

Is the library you're using built with split-objs?
If not, that would explain the long link time.

> that I can compile it much faster if I selectively import the needed
> modules, so figure the actual compilation/link time is more like 15 to 30
> seconds. (This is Windows on a very old laptop.) I'm used to working in
> Python, so I'm used to a nearly instant code-build-test cycle, and GUI
> applications in PyQt run briskly, faster than ghci/qtHaskell.
> Now I'm wondering if Hugs is a faster interpreter.

Usually it isn't. It's faster loading the code than ghci, but slower running it.

> So during development I don't want to give up the quick cycle you get with
> an interpreter, but the application may be much too slow to use in any
> meaningful way without compilation. Any advice welcome. Maybe there is a
> way to speed up the interpretation.

Smaller modules, so that only the hopefully few modules that were changed or depend on a 
changed module need be recompiled?
(Not sure that would help with linking, though)

> -Mike

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