Prime numbers list generator

primes :: Integral t => t -> t -> t
primes x y =
  if mod y x /= 0 && x <= y
    then primes (x + 1) y
    else x

primesLessThan :: Integral a => a -> [a]
primesLessThan z =
  [2, 3] ++
  filter
    (/= 0)
    [ if x > primes 2 x
      then 0
      else x
    | x <- [4 .. z]
    ]

main = print $ primesLessThan 1000


-- [2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59,
-- 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131,
-- 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197,
-- 199, 211, 223, 227, 229, 233, 239, 241, 251, 257, 263, 269, 271,
-- 277, 281, 283, 293, 307, 311, 313, 317, 331, 337, 347, 349, 353,
-- 359, 367, 373, 379, 383, 389, 397, 401, 409, 419, 421, 431, 433,
-- 439, 443, 449, 457, 461, 463, 467, 479, 487, 491, 499, 503, 509,
-- 521, 523, 541, 547, 557, 563, 569, 571, 577, 587, 593, 599, 601,
-- 607, 613, 617, 619, 631, 641, 643, 647, 653, 659, 661, 673, 677,
-- 683, 691, 701, 709, 719, 727, 733, 739, 743, 751, 757, 761, 769,
-- 773, 787, 797, 809, 811, 821, 823, 827, 829, 839, 853, 857, 859,
-- 863, 877, 881, 883, 887, 907, 911, 919, 929, 937, 941, 947, 953,
-- 967, 971, 977, 983, 991, 997]