type values=[
  |  `Int of int
  |  `Sym of string
  ]
type rvalues=[
    values
  | `PairVal of values * values
  ]
type arrays=[
    `ConcArray of values array
  | `SymArray of string * int
  ]
type rarrays=[
    arrays
  | `PairArray of arrays * arrays
  ]
type side= Left | Right

type codmem=
  [ rvalues
  | rarrays
  ]
type mem=(string, codmem) Hashtbl.t

let proj_mem (m:mem) s=
  let proj:mem=Hashtbl.create (Hashtbl.length m) in
  let _=Hashtbl.iter (fun a->fun b->
                             match b with
                             | `Int(_) | `Sym(_) -> Hashtbl.add proj a b;
                             | `PairVal(v1, v2) -> if s=Left then ((Hashtbl.add proj a v1);)  else Hashtbl.add proj a v2;
                             | `ConcArray(_) | `SymArray(_, _) ->  Hashtbl.add proj a b;
                             | `PairArray(v1,v2) -> if s=Left then ((Hashtbl.add proj a v1);) else Hashtbl.add proj a v2;
                     ) m
  in proj