def logical_lines:
  foreach inputs as $line (
    {buf: [], out: null};
    if (.buf | length) == 0 or ($line | test("^\\s+\\S")) then
      # continuation line
      { buf: (.buf + [$line]), out: null }
    else
      # output line
      { buf: [$line], out: (.buf | join("")) }
    end;
    if .out != null then .out else empty end);

logical_lines