Support completion for keys of a hash table

[gzqx]

Thank you for this wonderful project. I enjoy using it for quite some time.

However, I noticed that it seems to lack the ability to do semantic completion for:

If I have a hash table

%b={
	"apple"=>"good",
	"orange"=> "bad",
}
$a=\%b

It seems that it cannot auto-complete for neither $a->{ nor %b{, which IMHO is possible and would be really helpful.

I have not fully checked the document and code, so if the feature is already included I sincerely apologize in advance.

[FractalBoy]

This is difficult to do for the same reason it's difficult to know what methods are available on a variable.

We could collect all hash keys found in the document and offer those for auto complete but it's impossible to know what the keys are across files.