You can no way modify the string via this iterator. The easiest way: split it into a sequence via the same-named proc (just save it into a variable), and then in the `for` loop use `mitems` iterator on it, it allows modifying. Then `join` the sequence into a new string.
Or w/o modifying: use a variable in the loop (`var s=line.strip`), do any processing, then concatenate into a new string, defined empty before the loop. To syntax-highlight Nim code in the forum posts wrap it like in the hint below the textarea.
