1		:- multifile generate/2.
2		:- multifile shrink/3.
3
4		:- use_module(library(lists),[is_list/1,maplist/2]).
5		:- use_module(library(random),[random_permutation/2]).
6
7		% mutation of a list
8		generate(mutation(L:list),Value) :-
9		flattened(L) ,
10		random_permutation(L,Value).
11		% mutation of a list of lists
12		generate(mutation(ListOfLists:list),Value) :-
13		% mutate each list on its own
14		maplist(random_permutation,ListOfLists,Temp) ,
15		% also mutate the whole list
16		random_permutation(Temp,Value).
17
18		% mutation of trees
19		% random permutation of a binary tree
20		generate(mutation(Tree:tree(_)),Value) :-
21		\+ is_list(Tree) ,
22		tree_to_list(Tree,TreeList) ,
23		random_permutation(TreeList,TreePerm) ,
24		list_to_tree(TreePerm,Value).
25
26		% random permutation of several binary trees given in a list
27		generate(mutation(List:tree(_)),Value) :-
28		maplist(tree_to_list,List,TreeList) ,
29		flatten(TreeList,FlattenedList) ,
30		random_permutation(FlattenedList,TreePerm) ,
31		list_to_tree(TreePerm,Value).
32
33		shrink(mutation(_:Type),Value,Shrunken) :-
34		shrink(Type,Value,Shrunken).
35
36		% flatten a nested list
37		flatten([],[]) :- !.
38		flatten(H,[H]) :- \+is_list(H).
39		flatten([H|T],List) :-
40		flatten(H,L1) ,
41		flatten(T,L2) ,
42		append(L1,L2,List).
43
44		% tests if list is flattened
45		flattened(L) :-
46		flatten(L,L).
47
48		% convert all Key-Value pairs to Key
49		avl_list_to_list(AVLList,List) :-
50		findall(Key,member(Key-_,AVLList),List).
51
52		% convert (Index,Value) to Value
53		seq_to_list(Seq,List) :-
54		findall(Value,member((_,Value),Seq),List).