Actually that will be useful to me as well, so I would do it this way:
julia> lineparser( t :: Type, s :: String ) = parse.(t,split(s, c -> c <= ' ', keepempty=false))
julia> file = open("teste.dat","r")
IOStream(<file teste.dat>)
julia> lineparser(Int64,readline(file))
5-element Array{Int64,1}:
1
2
3
4
5
julia> x2 = lineparser(Float64,readline(file))
2-element Array{Float64,1}:
1.0
2.0