// leaves lines enclosed in brackets alone
sS autoUnindent_honoringBrackets(S s) {
  LS l = lines_honoringBrackets(s);
  if (empty(l)) ret s;
  
  // find indent
  int n = Integer.MAX_VALUE;
  for (S line : l)
    n = min(n, getIndentOfLine(line));
  if (n == 0) ret s;
  
  // unindent
  int _n = n;
  ret lines_possiblyRTrim(s, map(l, line -> substring(line, _n));
}