今日は 第6章:モジュール キーから値へのマッピング (位置 2545/11175) まで読み進めました。
読み進むうちに、だんだん疑問が増えてきました。
Just
は大文字で始まるので普通の関数じゃないんだろけどでは何だろう?
any
という関数は Data.List
モジュールにも Prelude
にもあるけど同じものなのか
- 上を確かめたくて、関数が同一であるかを調べようとしたけれど、どうやって調べれば良いのか。(他の言語みたいに
(List.any) == (any)
とは出来ない)
今まで出てた関数
5 + 2 == 8
5 * 2 == 10
5 - 2 == 3
5 / 2 == 2.5
( True || False ) == True
( True && False ) == False
not True == False
succ 'c' == 'd'
min 4 5 == 4
max 'a' 'z' == 'z'
div 92 3 == 30
mod 14 5 == 4
[1,2,3] ++ [4,5] == [1,2,3,4,5]
'a':" long time" == "a long time"
"abcdef" !! 2 == 'c'
( [1,2,3] < [1,2,4] ) == True
( "bbc" > "abc" ) == True
( [1,2,3] <= [1,2,4] ) == True
( "bbc" >= "abc" ) == True
( "abc" == "abc" ) == True
(1.0 /= 1.5) == True
head [1..] == 1
tail [1,2,3] == [2,3]
init [1,2,3,4] == [1,2,3]
length ['a'..'z'] == 26
null [] == True
reverse [1,2,3] == [3,2,1]
take 3 [1..] == [1,2,3]
drop 7 [1..10] == [8,9,10]
maximum [1,10,2] == 10
minimum [3,2,4] == 2
sum [1,10,100] == 10
product [2,3,4] == 24
elem 4 [1,2,3,4,5] == True
take 10 ( cycle "abc") == "abcabcabca"
take 5 ( repeat 'x') == "xxxxx"
replicate 5 'x' == "xxxxx"
odd 5 == True
even 8 == True
fst (1,'A') == 1
snd (1,'A') == 'A'
zip [1..] "ABC" == [(1,'A'),(2,'B'),(3,'C')]
show 4.25 == "4.25"
(read "4" :: Int) == 4
(minBound :: (Bool, Int, Char)) == (False,-9223372036854775808,'\NUL')
(maxBound :: (Bool, Int, Char)) == (True,9223372036854775807,'\1114111')
fromIntegral (div 5 3) + 1.5 == 2.5
compare 1 2 == LT
zipWith (*) [1..3] [10,20,30] == [10,40,90]
flip (++) "DEF" "ABC" == "ABCDEF"
map (10-) [1..3] == [9,8,7]
filter (<3) [1..10] == [1,2]
takeWhile (/= 'd') "abracadabra" == "abraca"
foldl (-) 10 [1,2] == 7
foldr (-) 10 [1,2] == 9
foldl1 (-) [10,1,2] == 7
foldr1 (-) [1,2,10] == 9
and [True, False, True] == False
or [True, False, True] == True
scanl (+) 0 [1,2,3] == [0,1,3,6]
scanr (+) 0 [1,2,3] == [6,5,3,0]
scanl1 (+) [1,2,3] == [1,3,6]
scanr1 (+) [1,2,3] == [6,5,3]
abs (-9) == 9
sqrt 9 == 3.0
negate 3.0 == -3.0
negate $ sqrt $ abs (-9) == -3.0
(negate . sqrt . abs) (-9) == -3.0
List.nub "abracadabra" == "abrcd"
List.sort [9,8..0] == [0,1,2,3,4,5,6,7,8,9]
List.words "I don't like it!" == ["I","don't","like","it!"]
List.group "aaabbcca" == ["aaa","bb","cc","a"]
List.tails [1,2,3] == [[1,2,3],[2,3],[3],[]]
List.isPrefixOf "Hi" "Hiroshi!" == True
List.any (== 'c') "abcdef" == True
List.isInfixOf "abc" "xxabcyy" == True
List.foldl'
List.foldr'
List.find (== 0) [1,2,3] == Nothing
Char.ord 'A' == 65
Char.chr 97 == 'a'
Char.digitToInt '2' == 2
Map.fromList [(1,"One"), (2,"Two")] == fromList [(1,"One"),(2,"Two")]
Map.lookup 2 $ Map.fromList [(1,"A"), (2,"B")] == Just "B"
Map.fromListWith (+) [("A",1),("B",2),("A",3)] == fromList [("A",4),("B",2)]