13 August 2016

Since my IBM 5100 has both BASIC and APL, I thought I'd try an APL version of the benchmark. It should be considered an idomatic—rather than a strict—port, as it is expressed in such a way as to perform the modulus function on the entire vector of identified primes. In the BASIC versions, the divisions are performed one at a time and the inner loop is terminated early at the first prime the candidate is evenly divisble by.

    ∇ FOUND←PRIMES N;FOUND;COUNT
[1]   FOUND←1⍴2
[2]   COUNT←3
[3]  START:→(N=⍴FOUND)/0
[4]   →(0∈FOUND|COUNT)/NEXT
[5]   FOUND←FOUND,COUNT
[6]  NEXT:COUNT←COUNT+1
[7]   →START
    ∇