run-cpp-on-web: vega

root-rule.js

const root_rule = {
  "data": {"values": [{"x": -1}]},
  "encoding": {"x": {"field": "x", "type": "quantitative"}},
  "layer": [
    {"mark": {"type": "rule", "strokeDash": [4, 8]}},
    {"mark":
      {
        "type": "text",
        "align": "right",
        "baseline": "bottom",
        "dx": -4,
        "dy": 10,
        "x": "width",
        "fontSize": 20,
        "text": "root = -1.0"
      }
    }
  ]
};