feat: make most types generic on SignalRef or ExprRef

[domoritz]

[marr]

Hi, is this still something that is planned? I'm a Vega beginner, and maybe I'm missing something simple. My data has a numeric value field and a nominal "unit" field. I render a faceted view based on another column called "variable" and use a temporal x axis. I would like to have the chart have a title like "variable (unit)" -- the unit is repeated for each row, so I'm not sure how I'd do that.

I will try putting together an example in the editor.

[domoritz]

Yes, still planned. I need to pick it up again.

[marr]

Yes, still planned. I need to pick it up again.

Thanks @domoritz --

Here is a simple chart in the editor

Just so I'm clear, there is no way to have the two y axis labels dynamic: "Var 1 (psi)" "Var 2 (psi)"

Instead of "value" (the column name).