complexToTex function
\complexnum{1+2i}, \complexnum{1:30} (polar).
Implementation
String complexToTex(String input, {SiOptions options = const SiOptions()}) {
final c = _parseComplex(input, options);
if (c == null) return numToTex(input, options: options);
return _formatComplex(c, options).$1;
}