1		% evaluation of ProB AST integer expressions
2
3		:- use_module(library(lists),[is_list/1,min_member/2,max_member/2]).
4		:- use_module(library(avl),[avl_to_list/2,list_to_avl/2]).
5
6		% return integer ast node
7		int_prob(Expression,b(integer(Value),integer,[])) :-
8		int(Expression,Value).
9
10		% return prolog value
11		int(b(Expression,_,_),Value) :-
12		Expression =.. [Type,_,_] ,
13		member(Type,[add,minus,multiplication,div,power_of,modulo]) ,
14		% catch too big numbers or evaluation errors
15		(on_exception(_,eval(b(Expression,_,_),Value),fail)
16		-> true
17		; int(b(max_int,_,_),Value)).
18
19		int(b(max_int,_,_),3).
20		/*preferences:get_preference(maxint,Max).*/
21		int(b(min_int,_,_),-1).
22		/*preferences:get_preference(minint,Min).*/
23
24		int(b(integer(Value),_,_),Value).
25
26		int(int(Value),Value).
27
28		int(b(card(Set),_,_),Value) :-
29		sint(Set,ValueSet) ,
30		length(ValueSet,Value).
31
32		int(b(unary_minus(Expr),_,_),Value) :-
33		int(Expr,Temp) ,
34		Value is -(Temp).
35
36		% prob ast sets
37		% not-well-defined for empty set
38		int(b(max(b(set_extension([]),set(_),_)),integer,_),0).
39		int(b(min(b(set_extension([]),set(_),_)),integer,_),0).
40		int(b(max(b(set_extension(ProBValueList),set(integer),_)),integer,_),Max) :-
41		maplist(ast_to_value,ProBValueList,List) ,
42		max_member(Max,List).
43		int(b(min(b(set_extension(ProBValueList),set(integer),_)),integer,_),Min) :-
44		maplist(ast_to_value,ProBValueList,List) ,
45		min_member(Min,List).
46
47		% prob value sets
48		% also interpret max, min of empty sets for shrinking of
49		% not well defined integer expressions
50		int(b(max(b(value([]),set(integer),[])),integer,[]),0).
51		int(b(min(b(value([]),set(integer),[])),integer,[]),0).
52
53		int(b(max(b(value(avl_set(empty)),set(integer),[])),integer,[]),0).
54		int(b(min(b(value(avl_set(empty)),set(integer),[])),integer,[]),0).
55		% list set
56		int(b(max(b(value(Set),set(integer),_)),integer,_),Max) :-
57		is_list(Set) ,
58		max_member(MaxMem,Set) ,
59		MaxMem = int(Max).
60		int(b(min(b(value(Set),set(integer),_)),integer,_),Min) :-
61		is_list(Set) ,
62		min_member(MinMem,Set) ,
63		MinMem = int(Min).
64
65		% avl set
66		int(b(max(b(value(avl_set(Set)),set(integer),_)),integer,_),Max) :-
67		avl_to_list(Set,Temp) ,
68		findall(Key,member(Key-_,Temp),List) ,
69		max_member(MaxMem,List) ,
70		MaxMem = int(Max).
71		int(b(min(b(value(avl_set(Set)),set(integer),_)),integer,_),Min) :-
72		avl_to_list(Set,Temp) ,
73		findall(Key,member(Key-_,Temp),List) ,
74		min_member(MinMem,List) ,
75		MinMem = int(Min).
76
77		% evaluation
78		eval(b(add(Expr1,Expr2),_,_),Value) :-
79		int(Expr1,Value1) ,
80		int(Expr2,Value2) ,
81		Value is Value1 + Value2.
82		eval(b(minus(Expr1,Expr2),_,_),Value) :-
83		int(Expr1,Value1) ,
84		int(Expr2,Value2) ,
85		Value is Value1 - Value2.
86		eval(b(multiplication(Expr1,Expr2),_,_),Value) :-
87		int(Expr1,Value1) ,
88		int(Expr2,Value2) ,
89		Value is Value1 * Value2.
90		eval(b(div(Expr1,Expr2),_,_),Value) :-
91		int(Expr1,Value1) ,
92		int(Expr2,Value2) ,
93		% round values to be able to interpret not-well-defined expressions
94		% so shrinking will be accepted by ProB interpreter
95		%Value is round(Value1 / Value2).
96		Value is Value1 / Value2.
97		eval(b(modulo(Expr1,Expr2),_,_),Value) :-
98		int(Expr1,Temp1) , Value1 is integer(Temp1) , % meanwhile bugfix (see thesis, chapter 2):
99		int(Expr2,Temp2) , Value2 is integer(Temp2) , % problem with mod(0.0,_) in SICStus 4.3.1 implementation, so integer/1 fixes the issue
100		Value is mod(Value1,Value2).
101		eval(b(power_of(Expr1,Expr2),_,_),Value) :-
102		int(Expr1,Value1) ,
103		int(Expr2,Value2) ,
104		Value is Value1 ^ Value2.