repeat

(repeat x)
(repeat n x)

返回一个包含 nx 的惰性序列。

如果不指定 n ,那么值 x 可以被包含无限次。

; 定义一个包含 10 个 "hi" 的惰性序列

user=> (def ten-hi (repeat 10 "hi"))
#'user/ten-hi

user=> ten-hi
("hi" "hi" "hi" "hi" "hi" "hi" "hi" "hi" "hi" "hi")


; 定义一个包含无限个 "hi" 的惰性序列

user=> (def infinite-hi (repeat "hi"))
#'user/infinite-hi

user=> (take 10 infinite-hi)
("hi" "hi" "hi" "hi" "hi" "hi" "hi" "hi" "hi" "hi")

user=> (take 20 infinite-hi)
("hi" "hi" "hi" "hi" "hi" "hi" "hi" "hi" "hi" "hi" "hi" "hi" "hi" "hi" "hi" "hi" "hi" "hi" "hi" "hi")

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