seq
seq は任意のコレクション上のリストビューです:strict なコレクションは強制されます（リストはそのまま通り抜け、ベクターと文字列は変換され、マップはエントリごとに 2 要素ベクターを、セットは要素ごとに 1 メンバーを供給します。走査順はテーブルのもので、未規定）。lazy seq は同じビューを通じて1要素ずつ realize します。コレクション全体を辿る動詞は lazy 入力を先にすべて realize し、途中で止まる動詞（second、nth、some、take-while など）は1要素ずつ辿るため、無限の入力でも答えます。chunk 化はなく、全操作の空の結果は nil です。1引数形はトランスデューサーです。
| Name | Example | Result |
|---|---|---|
seq | (seq [1 2 3]) | (1 2 3) |
first | (first {:a 1}) | [:a 1] |
rest | (rest '(1 2 3)) | (2 3) |
next | (next [1]) | nil |
cons | (cons 1 [2 3]) | (1 2 3) |
list* | (list* 1 2 [3 4]) | (1 2 3 4) |
count | (count {:a 1 :b 2}) | 2 |
empty? | (empty? "") | true |
map | (map inc [1 2 3]) | (2 3 4) |
filter | (filter odd? [1 2 3 4]) | (1 3) |
mapv | (mapv inc [1 2 3]) | [2 3 4] |
filterv | (filterv odd? [1 2 3 4]) | [1 3] |
reduce | (reduce + 0 [1 2 3]) | 6 |
apply | (apply max 1 [2 3]) | 3 |
concat | (concat [1] '(2) #{3}) | (1 2 3) |
mapcat | (mapcat reverse [[1 2] [3 4]]) | (2 1 4 3) |
take | (take 2 [1 2 3]) | (1 2) |
drop | (drop 2 [1 2 3]) | (3) |
lazy-seq | (take 2 (lazy-seq (cons 1 nil))) | (1) |
lazy-cat | (take 3 (lazy-cat [0] [1 2])) | (0 1 2) |
repeat | (take 2 (repeat :x)) | (:x :x) |
cycle | (take 3 (cycle [1 2])) | (1 2 1) |
iterate | (take 2 (iterate inc 0)) | (0 1) |
repeatedly | (take 2 (repeatedly (fn [] 7))) | (7 7) |
range | (range 0 6 2) | (0 2 4) |
nth | (nth [1 2 3] 5 :none) | :none |
rand-nth | (rand-nth [:a]) | :a |
shuffle | (shuffle []) | [] |
keep | (keep inc [1 2 3]) | (2 3 4) |
keep-indexed | (keep-indexed (fn [i x] (when (odd? x) i)) [10 11 12]) | (1) |
map-indexed | (map-indexed vector [:a :b]) | ([0 :a] [1 :b]) |
every? | (every? odd? [1 3]) | true |
some | (some even? [1 3]) | nil |
remove | (remove odd? [1 2 3 4]) | (2 4) |
distinct | (distinct [3 1 3 2 1]) | (3 1 2) |
partition | (partition 2 1 [1 2 3]) | ((1 2) (2 3)) |
take-while | (take-while pos? [3 1 -1 5]) | (3 1) |
drop-while | (drop-while neg? [-2 -1 0 1]) | (0 1) |
interleave | (interleave [1 2] [:a :b]) | (1 :a 2 :b) |
interpose | (interpose 0 [1 2 3]) | (1 0 2 0 3) |
zipmap | (zipmap [:a] [1 2]) | {:a 1} |
group-by | (group-by odd? [1 3]) | {true [1 3]} |
sort | (sort [3 1 2]) | (1 2 3) |
sort-by | (sort-by count ["aaa" "b" "cc"]) | (b cc aaa) |
last | (last [1 2 3]) | 3 |
butlast | (butlast [1 2 3]) | (1 2) |
second | (second [1 2 3]) | 2 |
ffirst | (ffirst [[1 2]]) | 1 |
nfirst | (nfirst [[1 2 3]]) | (2 3) |
drop-last | (drop-last [1 2 3]) | (1 2) |
split-at | (split-at 2 [1 2 3 4]) | [(1 2) (3 4)] |
split-with | (split-with odd? [1 3 4 5]) | [(1 3) (4 5)] |
take-last | (take-last 2 [1 2 3]) | (2 3) |
nthnext | (nthnext [1 2 3] 1) | (2 3) |
nthrest | (nthrest [1 2 3] 0) | [1 2 3] |
dedupe | (dedupe [1 1 2 1]) | (1 2 1) |
partition-all | (partition-all 2 [1 2 3]) | ((1 2) (3)) |
partition-by | (partition-by odd? [1 3 2]) | ((1 3) (2)) |
take-nth | (take-nth 2 [1 2 3]) | (1 3) |
not-empty | (not-empty []) | nil |
empty | (empty [1 2]) | [] |
pmap | (pmap inc [1 2]) | (2 3) |