Alternative functional composition

[davidanthoff]

@tkf had another idea here.

For now I'll put on the backlog and think about it.

[tkf]

Replying to https://github.com/queryverse/VegaLite.jl/pull/227#issuecomment-569450659

This made me wonder if it makes sense to use Tuple{Any,NamedTuple} for this.

Hm, but that adds another level of parenthesis, and I'm trying hard to reduce those...

Does it? ("age:o", (scale = (rangeStep = 17,),)) has as many parentheses as vlfrag("age:o", (scale = (rangeStep = 17,),)).

[davidanthoff]

But you can do vlfrag("age:o", scale = (rangeStep = 17,)), which is one less level of parentheses, right?

[tkf]

Ah, yes, I forgot that.

[jotwin]

Hi, new here. I'm very naive, but I'm wondering why it can't be functions with keywords and let the type system sort it out. Something like this

vlplot(
    bar(),
    x("month(date):o", axis(title="Month of the year")),
    y("count()"),
    color(:weather,
        scale(domain=["sun","fog","drizzle","rain","snow"],
            range=["#e7ba52","#c7c7c7","#aec7e8","#1f77b4","#9467bd"]
        ),
        legend(title="Weather type")
    )
)

[davidanthoff]

I think that was actually how VegaLite.jl was designed many years ago :) One problem is that we now have to create all these functions, and many of them have names that we really don't want in the global namespace (a function called x seems like a bad idea).