let new_fun_frame opt_here opt_pre opt_post =
let may_cons acc lab x =
match x with
| None -> acc
| Some x -> (lab,x)::acc
in
let frame =
(may_cons
(may_cons
(may_cons [] Clabels.Post opt_post)
Clabels.Pre opt_pre)
Clabels.Here opt_here)
in
ref frame