marked-prime? ( n sieve -- ? )

Vocabulary

math.primes.erato

Inputs

n	an integer
sieve	a byte-array

Outputs

?

a boolean

Word description

Checks whether n has been marked as a prime number. sieve must be a byte-array returned by sieve. n must be between 2 and the limit given to sieve.

Definition

USING: kernel math math.order math.primes.erato.private
sequences ;

IN: math.primes.erato

: marked-prime? ( n sieve -- ? )
    [ integer>fixnum-strict ] dip
    2dup upper-bound 2 swap between? [ bounds-error ] unless
    over { 2 3 5 } member? [ 2drop t ] [ marked-unsafe? ] if ;