_buffered_read = proc (chan: _chan) returns (ast, string)
    len: int := chan.length / 4
       except when not_possible (*): len := 0 end
    if len > _free_space()
       then _gc$gc()
	    if len > _free_space()
	       then return(ast$new(), "insufficient room!") end
       end
    as: ast := ast$predict(1, len / 8)
    bvec: _bytevec := _io_buf()
    msg: string := "Done."
    index: int := 1
    max: int := 0
    while true do
	s: string
	s, index, max := _chan$get(chan, bvec, index, max, "\n", false)
	ast$addh(as, s)
	if index > max
	   then break end
	index := index + 1
	end
       except when not_possible, failure (why: string):
		   msg := why
	      when end_of_file:
		   if ~ast$empty(as)
		      then ast$addh(as, "") end
	      end
    _cvt[ast, _adv[string]](as).predict := 0
    return(as, msg)
    end _buffered_read