miller/docs/programs/sieve.mlr

# ================================================================
# Sieve of Eratosthenes: simple example of Miller DSL as programming language.
# ================================================================

# Put this in a begin-block so we can do either
#   mlr -n put -q -f name-of-this-file.mlr
# or
#   mlr -n put -q -f name-of-this-file.mlr -e '@n = 200'
# i.e. 100 is the default upper limit, and another can be specified using -e.
begin {
  @n = 100;
}

end {
  for (int i = 0; i <= @n; i += 1) {
    @s[i] = true;
  }
  @s[0] = false; # 0 is neither prime nor composite
  @s[1] = false; # 1 is neither prime nor composite
  # Strike out multiples
  for (int i = 2; i <= @n; i += 1) {
    for (int j = i+i; j <= @n; j += i) {
      @s[j] = false;
    }
  }
  # Print survivors
  for (int i = 0; i <= @n; i += 1) {
    if (@s[i]) {
      print i;
    }
  }
}