This gist and a Functional Society Gist to talk about Calculator homework, so people can share links and help each other to get the homework right and make questions, get you question answered and so on and on...
We need code a simple calculator in Scala and Haskell:
Calculator, basic operations: +, -, /, * (Remember State and Side Effects are not desired)
In Clojure + is a function. In haskell is a operator, If you want use him as function must be this way: (+) 2 2
It`s possible pass Functions as Arguments, but as Far as I know in haskell you need use nomads for that => http://stackoverflow.com/questions/3542397/passing-functions-as-argument
It`s also possible with Higher Order Functions...
Search for: "Higher Order Functions in Order" => http://learnyouahaskell.com/higher-order-functions
applyTwice :: (a -> a) -> a -> a
applyTwice f x = f (f x)
ghci> applyTwice (++ " HAHA") "HEY"
"HEY HAHA HAHA"
Back to the + here is another sample using Higher Order Functions:
ghci> zipWith' (+) [4,2,5,6] [2,6,2,3]
[6,8,7,9]
Cheers,
Diego Pacheco
I'm almost sure that we can do that in haskell but I just don't know how. I would like to create a function that receives a mathematical operator like parameter and execute inside. For other functions we can do something like 'map' and send. Then it'll be executed.
Thanks!