bar.lua

      local h = levee.Hub()

      local r, w = h.io:pipe()

      local len = 128*1024

      local buf = d.Buffer(len)

      print()
      h:spawn(function()
        local err = w:write(("X"):rep(len))
        print(err)
        w:close()
      end)

      while true do
        local err, n = r:read(buf:tail())
        if err then break end
        buf:bump(n)
      end
      print(buf:value())