- 36 名前：名無しさん♯ mailto:sage [2007/08/06(月) 08:16:02 ]
- 当たり前といったら当たり前だけど、guardがきちんと動いた。
#light
open Seq
type SeqBuilder () =
member b.Return a = singleton a
member b.Bind (m, k) = map_concat k m
member b.Let (x, f) = f x
let seq = SeqBuilder ()
let guard = function
| true -> singleton ()
| _ -> empty
let _ =
seq { let! x = {1..10} (* from *)
do! guard (x > 5) (* where *)
return (x * x) } (* select *)
|> iter (string_of_int >> print_endline)
(実行結果)
36
49
64
81
100
