hsman

[Lennart Kolmodin]

> Hi
>
>> How would it work on Unix? I assume that the command-line program just
>> takes it's input "from the command line", so it doesn't get invoked
>> until after you've finished typing the command...

Not necessarily true if completion is involved ... see below.

> However, I know that zsh can do funky things like
> autocompleting ssh paths etc - and I think I remember seeing that
> there was some way a program could tell zsh what it could autocomplete
> to - but that is a hazy memory from a while ago.

Have a look at the (unreleased) bash completion for ghc-pkg:

http://www.haskell.org/~kolmodin/code/ghc-bash-completion/ghc-pkg

source it in bash to get it started.
As you can see that ghc-pkg doesn't have special support for
autocompletion, but it's possible anyway.

To make it a bit simpler to write the completion, it's nice if the
application in question has support for it. A nice example of this is
darcs[1] which implements the command '--commands' and the flag
'--list-option'.

Cheers,
  Lennart Kolmodin

[1] http://www.abridgegame.org/repos/darcs-unstable/darcs_completion