tables.ml

   1 (** Global list of tables *)
   2
   3 open Printf
   4 open ListMore
   5
   6 type table = RA.table
   7
   8 let all : table list ref = ref []
   9
  10 (** FIXME table names case sensitivity? *)
  11 let by_name name = fun (n,_) -> n = name
  12
  13 (** @raise Error when no such table *)
  14 let get_from tables name =
  15   try
  16     List.find (by_name name) tables
  17   with Not_found -> failwith (sprintf "no such table %s" name)
  18
  19 let get name = get_from !all name
  20 let get_schema name = snd (get name)
  21 let check name = ignore (get name)
  22
  23 let add v =
  24   let (name,schema) = v in
  25   match List.find_all (by_name name) !all with
  26   | [] -> all := v :: !all
  27   | _ -> failwith (sprintf "table %s already exists" name)
  28
  29 let drop name = check name; all := List.remove_if (by_name name) !all
  30
  31 let alter name f =
  32   let alter_scheme ((n,s) as table) =
  33     if n = name then
  34       name, f s
  35     else
  36       table
  37   in
  38   all := List.map alter_scheme !all
  39
  40 let alter_add name col pos = alter name (fun s -> RA.Schema.add s col pos)
  41 let alter_drop name col = alter name (fun s -> RA.Schema.drop s col)
  42
  43 let print () = List.iter RA.print_table !all
  44
  45 let reset () = all := []
  46