very slow type (,ht) and linter (,hl)

[mayeranalytics]

Am I the only one experiencing very slow ,ht and ,hl?

With Haskell-vim-now I see a lot of gcc/clang compiling in the background every time I hit ,ht or ,hl. With large projects or when using heavy frameworks like Yesod the waiting time is really holding up the work flow.

I'm using Atom as a benchmark, I think they are using ghc-mod and/or hdevtools in the background and it's very snappy.

Remark: I noticed that Haskell-vim-now actually didn't install hdevtools although it is listed as a "necessary support binary".

[begriffs]

Haskell Vim Now uses ghc-mod internally, so I'm curious how Atom goes faster in that regard. Can you get a rough measurement of the two and tell me the speed difference?

Also the readme is out of date when it mentions hdevtools. For a time ghc-mod was broken and I switched to hdevtools but ghc-mod got fixed and I was able to switch back.

[mayeranalytics]

It Atom these operations run in < 1/2s
Emacs seems even faster than Atom.
In vim the same takes about 7s.

See the attached gifs.
Atom:

Emacs:

Vim:

[begriffs]

Thanks for the illustrations. That's pretty bad performance, let's figure it out.

HVN uses the ghc-mod in ~/.local/bin, which ghc-mod do the others use? Maybe there is a speed difference in different versions of ghc-mod.

[mayeranalytics]

I'm running ghc-8.0.1 in all cases.
To dig a bit deeper I ran lsof -r1 -u myname > out before opening Vim and Atom. With that output it's difficult to understand what exactly these are doing, but I can say this:

• both Vim and Atom use the same .local/bin/ghc-mod
• Differently to Vim, Atom very heavily interacts with ghc-mod when it opens the .hs file. Thereafter, the interactions with ghc-mod look very similar: Commands are sent (pipe) to the one ghc-mod process.
• Neither uses hdevtools

Maybe this issue has something to do with it.