Last login: Tue Feb 26 20:27:59 on ttys006
: ~ ; exec /Users/dmason/fs/Courses/cps506/Lectures/Haskell/ghci.sh
GHCi, version 7.10.3: http://www.haskell.org/ghc/  :? for help
[1 of 1] Compiling February27       ( lecture.hs, interpreted )
Ok, modules loaded: February27.
*February27> let a = 7
*February27> let f x = x + 5
*February27> f a
12
*February27> let id x = x
*February27> f

<interactive>:6:1:
    No instance for (Show (a0 -> a0))
      (maybe you haven't applied enough arguments to a function?)
      arising from a use of ‘print’
    In the first argument of ‘print’, namely ‘it’
    In a stmt of an interactive GHCi command: print it
*February27> :t f
f :: Num a => a -> a
*February27> f []

<interactive>:8:1:
    Non type-variable argument in the constraint: Num [t]
    (Use FlexibleContexts to permit this)
    When checking that ‘it’ has the inferred type
      it :: forall t. Num [t] => [t]
*February27> :t f
f :: Num a => a -> a
*February27> f 7
12
*February27> f 12.5
17.5
*February27> f 'a'

<interactive>:12:1:
    No instance for (Num Char) arising from a use of ‘f’
    In the expression: f 'a'
    In an equation for ‘it’: it = f 'a'
*February27> :t id
id :: t -> t
*February27> id 5
5
*February27> id 12.5
12.5
*February27> (id f) 5
10
*February27> :t (id f)
(id f) :: Num a => a -> a
*February27> id f 5
10
*February27> id id id f 7
12
*February27> id id id f []

<interactive>:20:1:
    Non type-variable argument in the constraint: Num [t]
    (Use FlexibleContexts to permit this)
    When checking that ‘it’ has the inferred type
      it :: forall t. Num [t] => [t]
*February27> let ls x = [x]
*February27> :t [4.5]
[4.5] :: Fractional t => [t]
*February27> :t ls
ls :: t -> [t]
*February27> ls 4
[4]
*February27> :t map
map :: (a -> b) -> [a] -> [b]
*February27> let g x y = x + y
*February27> :t g
g :: Num a => a -> a -> a
*February27> g 4 5
9
*February27> let h = g 4
*February27> :t h
h :: Num a => a -> a
*February27> h 5
9
*February27> :t map
map :: (a -> b) -> [a] -> [b]
*February27> f 5
10
*February27> map f [1,2,3]
[6,7,8]
*February27> :t map f
map f :: Num b => [b] -> [b]
*February27> let m a b c d = a
*February27> :t m
m :: t3 -> t -> t1 -> t2 -> t3
*February27> let m a b c = a
*February27> :t m
m :: t2 -> t -> t1 -> t2
*February27> :t map (g 3)
map (g 3) :: Num b => [b] -> [b]
*February27> :t map g
map g :: Num a => [a] -> [a -> a]
*February27> let j = map g [1,2,3]
*February27> head [1,2,3]
*February27> :t head
head :: [t] -> t
*February27> (head j) 41
42
*February27> let secnd (_:x:_) = x
*February27> (secnd j) 41
43
*February27>