don't push company-ghc when ghc-mod is disabled

[d12frosted]

Because it forces ghc-mod, so haskell layer doesn't respects the value of haskell-enable-ghc-mod-support.

Also, the question - company-dabbrev-code is already in company-backends-haskell-mode - so is it necessary to add it here? And is it safe?

[TheBB]

company-backends is a list of backends. Company tries each of them in turn until it finds one that can offer completions, at which point it stops and doesn't try any more. However, an element of this list can also be another list of backends, in which case all those backends are tried at the same time and their completions are bundled together.

Probably that's what's happening here with dabbrev: someone wanted dabbrev to offer completions even when the other backends do.

So you should consider whether this code shouldn't be like this instead:

(push (if company-enable-ghc-mod-support
          '(company-dabbrev-code company-yasnippet company-ghc)
        '(company-dabbrev-code company-yasnippet)
      company-backends-haskell-mode)

In your version, dabbrev and yasnippet will block ghc-mod from offering completions, which wasn't the case in the original code.

[d12frosted]

Ah I see. Thanks for explanations. It makes more sense now. So like it walks the list of backends and stops at (company-ghc company-dabbrev-code company-yasnippet) because it can complete code in haskell-mode. Neat.

In your version, dabbrev and yasnippet will block ghc-mod from offering completions, which wasn't the case in the original code.

Originally it was

(push '(company-ghc company-dabbrev-code company-yasnippet)
      company-backends-haskell-mode)))

So shouldn't it be

(push (if company-enable-ghc-mod-support
          '(company-ghc company-dabbrev-code company-yasnippet)
        '(company-dabbrev-code company-yasnippet)
      company-backends-haskell-mode)

then? OK, I just wanted to avoid code duplication, but didn't understand how backends works. 😊

[d12frosted]

@TheBB updated

[TheBB]

Thanks! Cherry-picked in develop. You can safely delete your branch.

I had to fix the variable name. :-P 7b8e996

[d12frosted]

Oops, my bad @TheBB ! Thanks for covering my back 😄