Multi-line format helper?

[mbostock]

Should we expose a multi-line format helper? You can do it yourself but it’s a bit verbose:

tickFormat(x, i, X) {
  const format1 = (x) => x.toLocaleString("it", { day: "numeric" });
  const format2 = (x) => x.toLocaleString("it", { month: "short" });
  const f1 = format1(x);
  const f2 = format2(x);
  return i > 0 && f2 === format2(X[i - 1]) ? f1 : [f1, f2].join("\n");
}

Maybe:

tickFormat: Plot.formatConditional({ day: "numeric" }, { month: "short" })

But, you’d also need a way to pass in the locale, perhaps the template.

[Fil]

Related:

• multiline ticks labels, draft #609 had this small DSL with a question mark at the start of a line to avoid consecutive repeats.
• the type for tickFormat doesn't support the third parameter (see normalize tickFormat's arguments #1669).