getOffsetBefore method
Returns the closest offset before offset
at which the input cursor can
be positioned.
Implementation
int? getOffsetBefore(int offset) {
final int? prevCodeUnit = _text!.codeUnitAt(offset - 1);
if (prevCodeUnit == null) {
return null;
}
return isLowSurrogate(prevCodeUnit) ? offset - 2 : offset - 1;
}