Function completion in Inf-haskell

[michelk]

Function-completion in the inferior-haskell-process with TAB. Currently, pressing TAB inserts spaces instead of suggesting completion.

In ESS, for example, this works like charm.

[hvr]

This is being worked on (see GHC#5687) but it will require GHC 7.8+ or a patched GHCi.

[gracjan]

@geraldus: Do we have this covered in interactive-haskell-mode?

[geraldus]

@gracjan I've disabled company-mode temporarily and it feels a bit strange that TAB indents line rather than provide completion, but I think this is a matter of choice, for example in my case I just got used to company which instantly popups completions list where TAB completes common-part, but in past I've used TAB to indent line (I can't recall was it some IDE or something else). I have no strong opinion which option should be defaulted. Also if we bind TAB to completion at point which key should be used to indent line?

[geraldus]

Looks like I misunderstood the subject when wrote my last comment. Are we talking about TAB-completions in interactive buffer or any haskell buffer?

[gracjan]

In inf-buffer.

[geraldus]

Oh, I see now… Also I can delete prompt itself.

I'm not familiar neither with comint-mode nor with inferior-haskell-mode. Can someone clarify what is the main advantage of Inf-Haskell comparing to Interactive-Haskell? Do we really need to keep them both?

Likely, prompt and completion improvements for Inf-Haskell would be duplication of existing functionality from Interactive Haskell. I don't like this.

[gracjan]

comint-mode is standard for Emacs and a lot of shell-like buffers are based on comint. It uses pseudo terminal. It defines some standard keys and protocols.

On the other hand haskell-interactive-mode is not based on anything and codes everything from scratch.

There should be one mode, comint based. Sadly there is currently more code in haskell-interactive-mode than in inf-haskell-mode so it is hard to guess which direction we should port features.

As it stands now both modes have advantages and disadvantages and there is no clear winner. It is indentation story all over again :(