src/numtheory/cl_nt_nextprobprime.cc

   1 // nextprobprime().
   2
   3 // General includes.
   4 #include "cl_sysdep.h"
   5
   6 // Specification.
   7 #include "cln/numtheory.h"
   8
   9
  10 // Implementation.
  11
  12 #include "cln/real.h"
  13
  14 namespace cln {
  15
  16 const cl_I nextprobprime (const cl_R& x)
  17 {
  18         if (minusp(x))
  19                 return 2;
  20         // Now x >= 0.
  21         var cl_I n = ceiling1(x);
  22         if (n <= 2)
  23                 return 2;
  24         // Now n>=3.
  25         if (evenp(n))
  26                 n = n+1;
  27         // Now n>=3 odd.
  28         loop {
  29                 if (isprobprime(n))
  30                         return n;
  31                 n = n+2;
  32         }
  33 }
  34
  35 }  // namespace cln