rangeToTex function
A range: 1 to 10 (siunitx's default phrase).
Implementation
String rangeToTex(String a, String b, {String? unit, SiOptions? options}) {
final o = options ?? const SiOptions();
return _withUnits(
[a, b],
unit,
o,
o['range-units'],
(p) => p.join(_textSetting(o, 'range-phrase')),
open: o['range-open-bracket'],
close: o['range-close-bracket'],
);
}