[Clojure] 合成関数

Clojure で Haskell のドット演算子のように合成関数を得るには clojure.core/comp を用いる。 user=> (filter (comp not nil?) ‘(a nil b nil c nil d)) (a b c d)


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Deprecated: Creation of dynamic property WP_Term::$category_count is deprecated in /usr/home/bugyo/public_html/b-log/wp-includes/category.php on line 379

Deprecated: Creation of dynamic property WP_Term::$category_description is deprecated in /usr/home/bugyo/public_html/b-log/wp-includes/category.php on line 380

Deprecated: Creation of dynamic property WP_Term::$cat_name is deprecated in /usr/home/bugyo/public_html/b-log/wp-includes/category.php on line 381

Deprecated: Creation of dynamic property WP_Term::$category_nicename is deprecated in /usr/home/bugyo/public_html/b-log/wp-includes/category.php on line 382

Deprecated: Creation of dynamic property WP_Term::$category_parent is deprecated in /usr/home/bugyo/public_html/b-log/wp-includes/category.php on line 383
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[Clojure] 空リストか否か

Clojure では nil と空リストは同じではない。 (= nil ‘()) => false よって、再帰の停止条件などでは空リストか否かを返す述語 empty? を使う。 (defn sum [lst] (if (empty? lst) 0 (+ (first lst) (sum (rest lst)))))


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Deprecated: Creation of dynamic property WP_Term::$category_count is deprecated in /usr/home/bugyo/public_html/b-log/wp-includes/category.php on line 379

Deprecated: Creation of dynamic property WP_Term::$category_description is deprecated in /usr/home/bugyo/public_html/b-log/wp-includes/category.php on line 380

Deprecated: Creation of dynamic property WP_Term::$cat_name is deprecated in /usr/home/bugyo/public_html/b-log/wp-includes/category.php on line 381

Deprecated: Creation of dynamic property WP_Term::$category_nicename is deprecated in /usr/home/bugyo/public_html/b-log/wp-includes/category.php on line 382

Deprecated: Creation of dynamic property WP_Term::$category_parent is deprecated in /usr/home/bugyo/public_html/b-log/wp-includes/category.php on line 383
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