Question

I am trying to achieve prime number through recursion, I know how to do it with list.

Type error in function binding

primes :: [Int]   
primes = sieve [2..10]   
sieve[] = []   
sieve(x:xs) = x : sieve (filter p [xs])    
   where p x = xs `mod` x > 0

I also tried it doing with map and got type error in application

primes :: [Int]   
primes = sieve [2..10]   
sieve[] = []   
sieve(x:xs) = x : sieve (map (`mod` x > 0) [xs])

I am trying to achieve something similar what we do with list

sieve (a:x) = a:sieve [y| y<-x, y`mod`a > 0]

Answer 1

xs `mod` x

You can’t mod a list with an integer.

You probably meant

where p y = y `mod` x > 0

Notice I also had to change the parameter to y so it won’t shadow the x from the pattern on the previous line.

Also, filter p [xs] should be filter p xs.