Things I wish someone told me when doing Haskell

Hey people,

Long time not posts, yeah i know. Stuck with useless stuff. Finally got some time for a post. This would really be a bundle of snippets mainly for the beginner haskell coders that will soon be frustrated with all the functional elements. I'll try to keep this updated with every new frustration i get :D

IO

Doing IO was the worst thing i had to go through in haskell. As you know that haskell wont allow usual IO in a function, you have to explicitly use do to use a IO command

StdIn as a String


StdIn as an integer/double


Using a function inside a do block with IO

There are instance when our function has to perform IO function only in certain instances. Let's say I need to print numbers only under a certain condition. Then we will have a conditional statement in our function. But as we know every condition in haskell should be complete. If this else ?
For this simply use
return ()
Check this exmaple of printing the pascal triangle


Functions

Function defining has several forms and quite different according to what you wanna do.
For an example given here are two ways to define a function that would double the input amount if it's even or keeps the same if it's odd

Note : if is combined with else, otherwise is not combined with it