Question

And is there any way to fix it so that I can use them outside as well?
Thanks in advance.
I have something like this:

if(x==1)
   then
       someList<-aFunction (1,2)
   else
       someList<-aFunction (3,4)


steps involving someList here

Answer 1

You have misunderstood variables in Haskell: once they are defined, they never change their value, so if you are hoping to do an assignment inside a branch, that won’t work. However, maybe the following helps:

 let x = if (cond) then .. else .. in f x

Be careful not to read x in the if-then-else unless you know what you’re doing 🙂 Another reminder: if you use another let x = .. inside this construction, it will “shadow” the outer x, so it’ll effectively be a different, new variable.