Avoid recompilation if nothing has changed in /haskell-fun

[jonschoning]

haskell-emacs-init seems to take a full 20 seconds each time it is invoked, even if nothing in ~/.emacs-d/haskell-fun has changed. Manually invoking stack install in ~/.emacs-d/haskell-fun is nearly instantateous, but haskell-emacs-init takes ~20 seconds each time.

Can this delay be shortened to the same time that manually invoking stack install would take?

This would allow one to have haskell-emacs start in the emacs startup init script (invoking haskell-emacs-init) very easily.

[knupfer]

Thanks for reporting!
I think I know the reason for that, at the moment it calls on init unconditionally stack setup && stack install, so it seems that stack setup is eating the time here.

I'll try it tomorrow with stack.