_PreviousInitialByte
int32 _PreviousInitialByte(int32 offset) const;
const int32 previousInitial = _PreviousInitialByte(offset);
fSelStart = _PreviousInitialByte(fSelStart);
fCaretOffset = _PreviousInitialByte(fCaretOffset);
fCaretOffset = _PreviousInitialByte(line->offset);
offset = _PreviousInitialByte(offset);
offset = _PreviousInitialByte(offset);
previous = _PreviousInitialByte(offset);
offset = _PreviousInitialByte(offset);
int32 previous = _PreviousInitialByte(offset);