{{{  comments
; jump to previous non-space character.
; fold-comments are ignored. folds are closed, when leaving them.
}}}
@if-using not(PRE-CHAR)
  @use (PRE-CHAR)
  {{{  previous-text-character
  (deffun previous-text-character (
    if not(test-begin-line) (backward-character)
    else
    (
      previous-line
      {{{  move to next text-line
      while and(not(test-text),not(test-top))
      (
        if test-begin-fold (
          {{{  begin-fold => close it
          close-fold
          }}}
        ) else (
          {{{  fold-line -> open and move to end
          if test-fold-line (
            next-line
            goto-line-counter +(store-line -2)
          ) fi
          }}}
        ) fi
        {{{  otherwise up
        if not(test-text) (previous-line) fi
        }}}
      )
      }}}
      end-of-line
    ) fi
  ))
  }}}
@fi
