1		:- multifile generate/2.
2
3		% shrinking of all mutations defined in mutation.pl
4
5		:- use_module(library(lists),[is_list/1]).
6		:- use_module(library(random),[random_permutation/2,random_member/2,random/3]).
7
8		% mutation of ProB ast set expressions
9		generate(mutation(Expression:prob_ast_set_expr),NewExpression) :-
10		\+is_list(Expression) ,
11		random_set_expr_mutation(Expression,NewExpression).
12		% list of set expressions, random concatenation of expression then
13		% mutation of consisting set expressions
14		generate(mutation(Expressions:prob_ast_set_expr),NewExpression) :-
15		maplist(random_set_expr_mutation,Expressions,Mutated) ,
16		concatenate_ast(Mutated,[union,intersection],NewExpression).
17
18		% mutation of ProB value list sets
19		generate(mutation(L:prob_value_set),Value) :-
20		generate(mutation(L:list),Value).
21
22		% mutation of ProB value avl sets
23		generate(mutation(avl_set(Set):prob_value_set),avl_set(Value)) :-
24		avl_to_list(Set,AvlList) ,
25		random_permutation(AvlList,Permutation) ,
26		% don't sort values during creation of avl
27		ord_list_to_avl(Permutation,Value).
28		% mutate several avl sets and return a single one
29		generate(mutation(L:prob_value_set),avl_set(Value)) :-
30		maplist(avl_to_list,L,ListOfLists) ,
31		flatten(ListOfLists,List) ,
32		random_permutation(List,Permutation) ,
33		ord_list_to_avl(Permutation,Value).
34
35		% union, intersection, set_subtraction
36		random_set_expr_mutation(b(Expression,set(SetType),Info),b(NewExpression,set(SetType),Info)) :-
37		Expression =.. [Type,Expr1,Expr2] ,
38		member(Type,[union,intersection,set_subtraction]) ,
39		random(0,3,R) ,
40		random_set_expr_mutation_aux(R,Expr1,Expr2,NewExpr1,NewExpr2) ,
41		NewExpression =.. [Type,NewExpr1,NewExpr2].
42
43		% general_union, general_intersection
44		random_set_expr_mutation(b(Expression,set(SetType),Info),b(NewExpression,set(SetType),Info)) :-
45		Expression =.. [Type,Expr] ,
46		member(Type,[general_union,general_intersection]) ,
47		Expr = b(set_extension([Set]),set(set(SetType)),ArgInfo) ,
48		% just permutation
49		permutate_set(Set,NewSet) ,
50		NewExpr = b(set_extension([NewSet]),set(set(SetType)),ArgInfo) ,
51		NewExpression =.. [Type,NewExpr].
52
53		% if set_extension or value set is given
54		random_set_expr_mutation(Expression,NewExpression) :-
55		mutate_set(Expression,NewExpression).
56
57		% don't mutate empty set or interval
58		random_set_expr_mutation(Expression,Expression).
59
60		random_set_expr_mutation_aux(0,Expr1,Expr2,NewExpr1,Expr2) :-
61		random_set_expr_mutation(Expr1,NewExpr1).
62		random_set_expr_mutation_aux(1,Expr1,Expr2,Expr1,NewExpr2) :-
63		random_set_expr_mutation(Expr2,NewExpr2).
64		random_set_expr_mutation_aux(2,Expr1,Expr2,NewExpr1,NewExpr2) :-
65		random_set_expr_mutation(Expr1,NewExpr1) ,
66		random_set_expr_mutation(Expr2,NewExpr2).
67
68		% mutate set_extension nodes by replacing with matching set expressions like union or set_subtraction
69		mutate_set(b(set_extension(Set),SetType,Info),Mutation) :-
70		(random(0,2,0)
71		-> random_union(Set,SubSetA,SubSetB) ,
72		Temp = b(union(b(set_extension(SubSetA),SetType,Info),b(set_extension(SubSetB),SetType,Info)),SetType,[])
73		; random_subtraction(Set,SetA,SetB) ,
74		Temp = b(set_subtraction(b(set_extension(SetA),SetType,Info),b(set_extension(SetB),SetType,Info)),SetType,[])) ,
75		% random choice of further mutation
76		random(0,10,R) ,
77		(R < 7
78		-> Mutation = Temp
79		; random_set_expr_mutation(Temp,Mutation)).
80		mutate_set(b(value(Set),SetType,Info),b(value(NewSet),SetType,Info)) :-
81		generate(mutation(Set:prob_value_set),NewSet).
82
83		% just permutate given data, no generation
84		permutate_set(b(set_extension(Set),SetType,Info),b(set_extension(NewSet),SetType,Info)) :-
85		generate(mutation(Set:list),NewSet).
86		permutate_set(b(value(Set),SetType,Info),b(value(NewSet),SetType,Info)) :-
87		generate(mutation(Set:prob_value_set),NewSet).
88
89		% split a list in two sublists randomly
90		random_union([],[],[]).
91		random_union(List,A,B) :-
92		length(List,Length) ,
93		generate(integer([between(1,Length)]),LengthA) ,
94		LengthB is Length - LengthA ,
95		LengthA >= 0 , LengthB >= 0 ,
96		% set length of both sublists
97		length(A,LengthA) ,
98		length(B,LengthB) ,
99		% use append to find solutions
100		append(A,B,List).
101		random_union(_,[],[]).
102
103		% add random list B to first argument so that A - B = List
104		% like replace [1,2] with [1,2,3] - [3]
105		random_subtraction(List,A,B) :-
106		List = [b(_,Type,_)|_] ,
107		NType =.. [Type,[]] ,
108		generate(prob_ast_set(NType,[extension]),b(set_extension(B),_,_)) ,
109		append(List,B,A).