Repl autocompletion for composite type fields

[binarybana]

julia> z = match(r"a", "apa")
RegexMatch("a")

julia> z.<tab><tab>

I know I can find the names of a composite type with typeof(z).names but I'd rather the repl do it for me and sprinkle some of its automagic-super-duper-wonderful-tab-completion-dust all over that tuple. :)

[johnmyleswhite]

I also like this idea a lot. As a first step, I'd add a fields() function that does the names retrieval for you:

function fields(v)
  if typeof(v) == CompositeKind
    return v.names
  elseif typeof(typeof(v)) == CompositeKind
    return typeof(v).names
  else
    error("Cannot call fields() on a non-composite type")
  end
end

I've been using that specific hack for a while now.

julia> fields(1)
Cannot call fields() on a non-composite type
 in fields at none:7

julia> fields(OUTPUT_STREAM)
(:ios,:name)

julia> fields(IOStream)
(:ios,:name)

[pao]

MATLAB calls this method fieldnames(), and I recall I got shot down when I tried to add it months ago, though it didn't chain the lookup as this does.

[toivoh]

If it is added, it should probably filter out those names that are symbol("")?

[johnmyleswhite]

Hmm. I think fieldnames() would be great.

[JeffBezanson]

We have names(module); we could add this to that.

[pao]

This would be a natural extension to names().

[StefanKarpinski]

+1

[diegozea]

+1
I was looking for the same functionality of REPL