Created
October 11, 2017 16:48
-
-
Save menduz/0ba95eb9864da2724685530e67853011 to your computer and use it in GitHub Desktop.
DataWeave prime number generator
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
%dw 2.0 | |
output application/json | |
import some from dw::core::Arrays | |
fun isPrime(num: Number): Boolean = do { | |
// try primes <= 16 | |
if (num <= 16) | |
(num == 2) or (num == 3) or (num == 5) or (num == 7) or (num == 11) or (num == 13) | |
else if ( // cull multiples of 2, 3, 5 or 7 | |
((num mod 2) == 0) | |
or ((num mod 3) == 0) | |
or ((num mod 5) == 0) | |
or ((num mod 7) == 0) | |
) | |
false | |
// cull square numbers ending in 1, 3, 7 or 9 | |
else if( | |
sequence(1) | |
map ($ * 10) | |
takeUntil ($ * $) < num | |
some ( | |
(num mod ($ + 1)) == 0 | |
or (num mod ($ + 3)) == 0 | |
or (num mod ($ + 7)) == 0 | |
or (num mod ($ + 9)) == 0 | |
) | |
) | |
false | |
else | |
true | |
} | |
fun takeUntil<T>(list: Array<T>, condition: (T, Number) -> Boolean): Array<T> = do { | |
fun until(list: Array<T>, condition: (T, Number) -> Boolean, startIndex: Number): Array<T> = | |
list match { | |
case [] -> [] | |
case [head ~ tail] -> | |
if(condition(head, startIndex)) | |
[head ~ until(tail, condition, startIndex + 1)] | |
else | |
[head] | |
} | |
--- | |
until(list, condition, 0) | |
} | |
fun sequence(start = 0) = [start ~ sequence(start + 1)] | |
fun primeGenerator() = (sequence(0) filter isPrime($)) | |
fun primes(qty: Number, start: Number = 0) = | |
primeGenerator()[(start) to (start+qty-1)] | |
--- | |
// primeGenerator()[999] //999th prime number | |
primes(100) |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
this code is not working beyond 6... if you pass more than 6 to prime it wont take please solve and reply..