(** General basis set read from a file  *)
type primitive = {
    exponent: float ;
    coefficient: float
    }

type general_contracted_shell = Angular_momentum.t * (primitive array)

type t = Element.t * (general_contracted_shell array)


let string_of_primitive ?id prim =
  match id with
  | None -> (string_of_float prim.exponent)^" "^(string_of_float prim.coefficient)
  | Some i -> (string_of_int i)^" "^(string_of_float prim.exponent)^" "^(string_of_float prim.coefficient)


let string_of_contracted_shell (angular_momentum, prim_array) =
  let n = 
    Array.length prim_array
  in
  Printf.sprintf "%s %d\n%s"
    (Angular_momentum.to_string angular_momentum) n
    (Array.init n (fun i -> string_of_primitive ~id:(i+1) prim_array.(i))
     |> Array.to_list
     |> String.concat "\n")


let string_of_contracted_shell_array a =
  Array.map string_of_contracted_shell a
  |> Array.to_list
  |> String.concat "\n"


let to_string (name, contracted_shell_array) =
  Printf.sprintf "%s\n%s" name (string_of_contracted_shell_array contracted_shell_array)