Problem Statement

Write a boolean function that tells whether a given integer is prime.

Remember that   1   and all non-positive numbers are not prime. Use trial division. Even numbers greater than   2   may be eliminated right away. A loop from   3   to   √ n    will suffice,   but other loops are allowed.

Let's start with the solution:

fcn isPrime(n){
   if(n.isEven or n<2) return(n==2); 
   (not [3..n.toFloat().sqrt().toInt(),2].filter1('wrap(m){n%m==0}))
}