/*

  Decomposition of global contiguity using DCG in Picat.

  Cf global_contiguity_regular.pi which use (a decomposition of)
  regular constraint.

  There's duplicates so we use table to fix this.

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

*/

import dcg_utils.
import cp.

main => go.

% global_cardinality/2: must use table + flatten/1
go ?=> 
   N = 12,
   % length(Z,N),
   Z = new_list(N),
   % X is the proper list, Z is the flattened version
   All= findall(Z,global_contiguity(_X,Z,[])), 
   println(All),
   println(len=All.len),
   nl.
go => true.

% global_cardinality2. Must use table
go2 ?=> 
   N = 12,
   X = new_list(N),
   All = findall(X,global_contiguity2(X,[])),
   println(All),
   println(len=All.len),
   nl.

go2 => true.

% global_cardinality3.
% Don't work since many_of/2, any_except/2 are not generators, just parsers!
go3 ?=> 
   member(N,1..10),
   println(n=N),
   X = new_list(N),
   global_contiguity3(X,Z,[]),
   println(x=X),
   println(z=Z),
   fail,
   nl.

go3 => true.


table
global_contiguity(GC) --> zeros(Zs1), ones(Ones), zeros(Zs2), {GC = [Zs1,Ones,Zs2].flatten}.
zeros([])     --> [].
zeros([0|Zs]) --> [0], zeros(Zs).
ones([])      --> [].
ones([1|Os])  --> [1], ones(Os).

table
global_contiguity2 --> zeros2, ones2, zeros2.
zeros2 --> [].
zeros2 --> [0], zeros2.
ones2  --> [].
ones2  --> [1], ones2.


% table
% Ah, many_of/2, any_except/2 are not generators, just parsers
% so this doesn't work as a generator.
global_contiguity3([Z1,Ones,Z2]) --> {println(start)}, many_of(Z1,"0"), many_of(Ones,"1"),many_of(Z2,"0").
global_contiguity3([]) --> [].