(* あらかじめ ex08_3.ml を読み込んでおく必要あり *) 
#use "ex08_3.ml" 
 
(* person_t list 型のデータの例 *) 
let lst1 = [] 
let lst2 = [person1] 
let lst3 = [person2] 
let lst4 = [person1; person2; person3] 
let lst5 = [person2; person1; person1] 
 
(* person1, person2, person3 の定義については ex08_3.ml を参照 *) 
 
(* 目的：人のリスト lst のうち各血液型の人が何人いるかを集計する *) 
(* ketsueki_shukei : person_t list -> int * int * int * int *) 
let rec ketsueki_shukei lst = match lst with 
    [] -> (0, 0, 0, 0) 
  | {name = n; shincho = s; taiju = t; tsuki = ts; hi = h; 
     ketsueki = k} :: rest -> 
      let (a, o, b, ab) = ketsueki_shukei rest in 
      if k = "A" then (a + 1, o, b, ab) 
      else if k = "O" then (a, o + 1, b, ab) 
      else if k = "B" then (a, o, b + 1, ab) 
      else (a, o, b, ab + 1) 
 
(* テスト *) 
let test1 = ketsueki_shukei lst1 = (0, 0, 0, 0) 
let test2 = ketsueki_shukei lst2 = (1, 0, 0, 0) 
let test3 = ketsueki_shukei lst3 = (0, 0, 1, 0) 
let test4 = ketsueki_shukei lst4 = (1, 1, 1, 0) 
let test5 = ketsueki_shukei lst5 = (2, 0, 1, 0)