let rec make_stream ~env = function
PinitExp e -> begin
let e = add_type_to_expr ~env e in
match e.expr_t with
CTTexpConstant(CTTconstString s) ->
Istring(e,s)
| _ -> Isingle(e)
end
| PinitList(l) ->
let l = List.map (make_stream ~env) l in
Ilist { ist_dat = l; ist_loc = ("", 0) }