fibonacci#
fibonacci($n_or_pdl) – Fibonacci sequence constructor.
Mirrors upstream PDL::fibonacci (Primitive.pd pp_def 'fibonacci',
Pars => 'i(n); [o]x(n)'). The engine op pdl_run_fibonacci(i, x)
writes x[k] = x1+x2 with x1=1, x2=0 initially and the standard
carry { x2=x1; x1=x[k] } from k>0, producing 1,1,2,3,5,8,13,....
Two call forms, mirroring upstream’s PDL::fibonacci wrapper:
fibonacci(N)— scalar integer → N-element pdl$pdl->fibonacci— fills$pdlin-place (inplace flag)
The connector prepares the i input pdl (a sequence of counter
values, shape-match the desired output) and lets the engine do
the actual recurrence.