FP Laboratory 1

Working environment

Using the installation guide from Functional programming prepare your working environment.

How to verify it is working?

• Run ghci from the command line. it will start GHC Interpreter, the output should be something like this:

GHCi, version 8.6.5: http://www.haskell.org/ghc/  :? for help
Prelude>

• If you write expression, for example 1+2*3, it should be evaluated. You can close this interpreter by typing:q.

Topic

ghci> :l baby  
[1 of 1] Compiling Main             ( baby.hs, interpreted )  
Ok, modules loaded: Main.  
ghci> doubleMe 9  
18  
ghci> doubleMe 8.3  
16.6  

ghci> 2 + 15  
17  
ghci> 49 * 100  
4900  
ghci> 1892 - 1472  
420  
ghci> 5 / 2  
2.5

 
ghci> import Prelude

doubleSmallNumber x = if x > 100  
                        then x  
                        else x*2  

ghci> [1,2,3,4] ++ [9,10,11,12]  
[1,2,3,4,9,10,11,12]  
ghci> "hello" ++ " " ++ "world"  
"hello world"  
ghci> ['w','o'] ++ ['o','t']  
"woot"  

multThree :: (Num a) => a -> a -> a -> a  
multThree x y z = x * y * z