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Changed directory: /home/trifon/fmisync/Courses/2021_22/FP_2021_22/sandbox/lectures/haskell/
λ> :t 5
5 :: Num p => p
λ> :t []
[] :: [a]
λ> :t elem
elem :: (Foldable t, Eq a) => a -> t a -> Bool
λ> :t elem
elem :: Eq a => a -> [a] -> Bool
λ> :t show
show :: Show a => a -> String
λ> :t enumFromTo
enumFromTo :: Enum a => a -> a -> [a]
λ> :k Int
Int :: *
λ> :k Integer
Integer :: *
λ> :k [Int]
[Int] :: *
λ> :k (Int,Bool)
(Int,Bool) :: *
λ> :k Measurable
Measurable :: * -> Constraint
λ> :k Measurable Int
Measurable Int :: Constraint
λ> :k Measurable Bool
Measurable Bool :: Constraint
λ> larger 21439847328473248 74328327584758458458753
False
λ> larger 21439847328473248 743283275847
True
λ> larger 21439847328473248 0
True
λ> empty 0
True
λ> empty 4329874983274
False
λ> :t (1, 2)
(1, 2) :: (Num a, Num b) => (a, b)
λ> :k (Int, Bool)
(Int, Bool) :: *
λ> :t (,)
(,) :: a -> b -> (a, b)
λ> :k (,)
(,) :: * -> * -> *
λ> (,) 1 2 == (1,2)
True
λ> :k (,) Int Bool
(,) Int Bool :: *
λ> :k (Int, Bool)
(Int, Bool) :: *
λ> larger (4432843, 3247327647) (824383274, 1221)
True
λ> larger [1,4543,454365,5,243,243,32]
larger [1,4543,454365,5,243,243,32]
  :: (Measurable a, Num a) => [a] -> Bool
λ> size [1,4543,454365,5,243,243,32]
20
λ> size ([1,4543,454365,5,243,243,32],(123123321321,[(1,2),(3,4)]))
36
λ> :k Int
Int :: *
λ> :k Measurable
Measurable :: * -> Constraint
λ> :t False
False :: Bool
λ> :k Bool
Bool :: *
λ> :t Mon
Mon :: Weekday
λ> :t Sun
Sun :: Weekday
λ> :k Weekday
Weekday :: *
λ> :t today
today :: Weekday
λ> today
today :: Weekday
λ> x
2
λ> x
True
λ> today
сряда
λ> Fri
вече не знам
λ> :k Player
Player :: *
λ> :t Player
Player :: Name -> Score -> Player
λ> getPlayer katniss
"Katniss Everdeen"
λ> katniss
katniss :: Player
λ> :t name
name :: Player -> Name
λ> :t score
score :: Player -> Score
λ> name katniss
"Katniss Everdeen"
λ> score katniss
45
λ> :k Shape
Shape :: *
λ> :t Circle
Circle :: Double -> Shape
λ> :t Rectangle
Rectangle :: Double -> Double -> Shape
λ> :t radius
radius :: Shape -> Double
λ> :t width
width :: Shape -> Double
λ> :t height
height :: Shape -> Double
λ> :t circle
circle :: Shape
λ> :t rectangle
rectangle :: Shape
λ> circle
circle :: Shape
λ> rectangle
rectangle :: Shape
λ> today
Wed
λ> today == Thu
False
λ> today < Sat
True
λ> ((read "Thu")::Weekday) > today
True
λ> (read "Thu") > today
True
λ> read "Thu"
*** Exception: Prelude.read: no parse
λ> (read "Thu")::Weekday
Thu
λ> katniss
Player {name = "Katniss Everdeen", score = 45}
λ> katniss == Player "Katniss Everdeen" 55
False
λ> circle
Circle {radius = 2.3}
λ> circle < rectangle
True
λ> read "Circle 2.3" < Circle 4.5
*** Exception: Prelude.read: no parse
λ> ((read "Circle 2.3")::Shape) < Circle 4.5
*** Exception: Prelude.read: no parse
λ> read "Circle { radius = 2.3}" < Circle 4.5
True
λ> :t Just 5
Just 5 :: Num a => Maybe a
λ> :k Maybe
Maybe :: * -> *
λ> :t Nothing
Nothing :: Maybe a
λ> :t Just
Just :: a -> Maybe a
λ> :k Maybe
Maybe :: * -> *
λ> :k Maybe Int
Maybe Int :: *
λ> :k Maybe [Int]
Maybe [Int] :: *
λ> :k Maybe (Int,[Bool])
Maybe (Int,[Bool]) :: *
λ> :k Maybe (Maybe Int)
Maybe (Maybe Int) :: *
λ> :t Just Nothing
Just Nothing :: Maybe (Maybe a)
λ> getAt 5 [1..10]
Just 6
λ> getAt (-1) [1..10]
Nothing
λ> getAt 123321 [1..10]
Nothing
λ> 
λ> fromNat five
4
λ> fromNat five
5
λ> toNat (fromNat five)
Succ (Succ (Succ (Succ (Succ Zero))))
λ> fromNat (toNat 5)
5
λ> toNat 100
Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ Zero)))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))
λ> six
BitZero (BitOne One)
λ> fromBin six
6
λ> fromBin $ succBin $ succBin $ six
8
λ> l
Cons 1 (Cons 2 (Cons 3 Nil))
λ> fromList l
[1,2,3]
λ> listHead l
1
λ> listTail l
Cons {listHead = 2, listTail = Cons {listHead = 3, listTail = Nil}}
λ> listTail Nil
*** Exception: No match in record selector listTail
λ> listHead Nil
*** Exception: No match in record selector listHead
λ> fromList (l +++ l)
[1,2,3,1,2,3]
λ> t
Node {root = 3, left = Node {root = 1, left = Empty, right = Empty}, right = Node {root = 5, left = Empty, right = Empty}}
λ> depth t
2
λ> depth (leaf True)
1
λ> leaves 
leaves :: BinTree a -> [a]
λ> leaves t
[1,5]
λ> mapBinTree (+1) t
Node {root = 4, left = Node {root = 2, left = Empty, right = Empty}, right = Node {root = 6, left = Empty, right = Empty}}