/* 

  nreverse benchmark in Picat v3.

  bench/nreverse.pl
  https://github.com/SWI-Prolog/bench

  Changes: 
  - added output

  This Picat model was created by Hakan Kjellerstrand, hakank@gmail.com
  See also my Picat page: http://www.hakank.org/picat/

*/

main => go.


go =>
  nreverse([1,2,3,4,5,6,7,8,9,10,11,12,
            13,14,15,16,17,18,19,20,21,
            22,23,24,25,26,27,28,29,30],X),
  println(X),
  nl.

go => true.

% """
% generated: 25 October 1989
% option(s): 
%
%   nreverse
%
%   David H. D. Warren
%
%   "naive"-reverse a list of 30 integers
% """
top:-nreverse.

nreverse :-
   nreverse([1,2,3,4,5,6,7,8,9,10,11,12,
             13,14,15,16,17,18,19,20,21,
             22,23,24,25,26,27,28,29,30],_).

nreverse([X|L0],L) :- nreverse(L0,L1), concatenate(L1,[X],L).
nreverse([],[]).

concatenate([X|L1],L2,[X|L3]) :- concatenate(L1,L2,L3).
concatenate([],L,L).