Skip to content

Instantly share code, notes, and snippets.

Avatar

Bit Wombat bitwombat

View GitHub Profile
View stdin
instancesOfFunc> configure (lib)
Configuring instancesOfFunc-0.1.0.0...
instancesOfFunc> build (lib)
Preprocessing library for instancesOfFunc-0.1.0.0..
Building library for instancesOfFunc-0.1.0.0..
[1 of 1] Compiling InstancesOfFunc
/data/info/programming/haskell/haskellbook/exercises/Ch16/src/InstancesOfFunc.hs:28:31: error:
• Couldn't match expected type ‘a’ with actual type ‘b’
‘b’ is a rigid type variable bound by
View InstancesOfFunc.hs
module InstancesOfFunc where
import Test.QuickCheck
functorIdentity :: (Functor f, Eq (f a)) => f a -> Bool
functorIdentity f = fmap id f == f
functorCompose :: (Eq (f c), Functor f) => (a -> b) -> (b -> c) -> f a -> Bool
functorCompose f g x = (fmap g (fmap f x)) == (fmap (g . f) x)
View gist:b97497bd8dd9b2d2ad7ed6466140d880
cups:
Installed: (none)
Candidate: 2.2.7-1ubuntu2
Version table:
2.2.7-1ubuntu2 500
500 http://au.archive.ubuntu.com/ubuntu bionic/main amd64 Packages
@bitwombat
bitwombat / Spec.hs
Created Jul 25, 2019
Page 562 exercises
View Spec.hs
module Page562Tests where
import Page562
import Test.QuickCheck
import Data.List (sort)
--Ex 1
halfIdentity :: (Fractional a, Num a) => a -> a
halfIdentity = (*2) . half
@bitwombat
bitwombat / Spec.hs
Created Jul 25, 2019
Page 562 exercises
View Spec.hs
module Page562Tests where
import Page562
import Test.QuickCheck
import Data.List (sort)
--Ex 1
halfIdentity :: (Fractional a, Num a) => a -> a
halfIdentity = (*2) . half
@bitwombat
bitwombat / letter_freq.py
Last active Jul 23, 2019
Calculate the frequency of letters, via generic Python
View letter_freq.py
'''Character counting as a fold'''
from functools import reduce
from itertools import repeat
from os.path import expanduser
# charCounts :: String -> Dict Char Int
def charCounts(s):
'''A dictionary of
View Page475_trimmed.hs
module Page475 where
-- Ex 5
either' :: (a -> c) -> (b -> c) -> Either a b -> c
either' f g eab =
case eab of
Left a -> f a
Right b -> g b
-- Ex 6
@bitwombat
bitwombat / Page475.hs
Created Jul 19, 2019
HPFFP Exercise page 475
View Page475.hs
module Page475 where
f :: Either a b -> [a] -> [a]
f c d = case c of
Left x -> d ++ [x]
_ -> d
lefts' :: [Either a b] -> [a]
lefts' e = foldr (f) [] e
@bitwombat
bitwombat / Page447.hs
Created Jul 16, 2019
Ex 2 on Page 447
View Page447.hs
module Page447 where
import Data.Char
capitalizeWord :: String -> String
capitalizeWord (c:cs) = toUpper c : cs
endsWithPeriod :: String -> Bool
endsWithPeriod word = last word == '.'
@bitwombat
bitwombat / Page442.hs
Created Jul 15, 2019
Solutions to Page442 exercise of HPFFP
View Page442.hs
module Page442 where
data BinaryTree a =
Leaf
| Node (BinaryTree a) a (BinaryTree a)
deriving (Eq, Ord, Show)
preorder :: BinaryTree a -> [a]
preorder Leaf = []
preorder (Node left val right) = [val] ++ (preorder left) ++ (preorder right)