1		:- multifile generate/2.
2		:- multifile shrink/3.
3
4		:- use_module(library(random),[random/3]).
5
6		% list of options:
7		% size:Size to set the size of record, names:NameList to specify the used names in the record
8		% if both Options are given the length of NameList will determine the size of the record
9		%
10		% the optional declaration of a NameList is useful to be able to generate
11		% different records with the same field names, so the ProB Interpreter is able to
12		% compare two records with the chance of success (different names are also accepted, but those
13		% comparisons would probably never succeed with the addition of random selected names)
14
15		generate(prob_ast_record(Type),Record) :-
16		\+is_list(Type) ,
17		generate(prob_ast_record(Type,[]),Record).
18
19		% generate a list of records with the same field names but mixed values
20		generate(prob_ast_record(Type,Options),ListOfRecords) :-
21		member(list:Size,Options) ,
22		(member(names:NameList,Options)
23		-> true
24		; (member(size:R,Options)
25		-> true
26		; random(1,20,R)) ,
27		generate(list(atom([size:5,alph]),[size:R]),NameList)) ,
28		length(ListOfRecords,Size) ,
29		maplist(generate(prob_ast_record(Type,[names:NameList])),ListOfRecords).
30
31		% record
32		generate(prob_ast_record(Type,Options),b(rec(Record),record(FieldTypes),[])) :-
33		member(Type,[integer(_),string(_),boolean(_),any(_)]) ,
34		(member(size:Size,Options)
35		-> true
36		; random(1,20,Size)) ,
37		length(NType,Size) ,
38		% any or given type
39		(Type = any(InOptions)
40		-> maplist(generate(ground_type(InOptions)),NType)
41		; length(NType,Size) ,
42		maplist(equal(Type),NType)) ,
43		(member(names:NameList,Options)
44		-> length(NameList,NewSize) ,
45		length(Record,NewSize) ,
46		% size of name list is more substantial than given size
47		length(NNType,NewSize) ,
48		maplist(equal(Type),NNType) ,
49		maplist(prob_field(ast),NNType,NameList,Record)
50		; % list of single type to use maplist
51		length(Record,Size) ,
52		maplist(prob_field(ast),NType,Record)) ,
53		maplist(field_value_to_type,Record,FieldTypes).
54
55		equal(A,A).
56
57		% shrink single record
58		shrink(Type,b(rec(Record),RecType,Info),b(rec(Shrunken),RecType,Info)) :-
59		Type =.. [prob_ast_record|_] ,
60		shrink(list(_),Record,Temp) ,
61		% don't shrink to an empty record
62		(Temp = [] -> Shrunken = Record , ! ; Shrunken = Temp).
63		% shrink list of records
64		shrink(Type,ListOfRecords,Shrunken) :-
65		Type =.. [prob_ast_record|_] ,
66		is_list(ListOfRecords) ,
67		maplist(shrink(prob_ast_record),ListOfRecords,Shrunken).
68
69		% generation of a field used in records
70		% not defined within generate/2 to be able to use maplist with list of names
71		% ProBType is either ast or value
72		prob_field(ProBType,Type,field(VarName,FieldValue)) :-
73		generate(atom([alph,size:5]),VarName) ,
74		gen_type(Type,ProBType,NType) ,
75		generate(NType,FieldValue).
76		prob_field(ProBType,Type,VarName,field(VarName,FieldValue)) :-
77		gen_type(Type,ProBType,NType) ,
78		generate(NType,FieldValue).
79
80		% abstract value to its type in a field
81		field_value_to_type(field(VarName,FieldValue),field(VarName,FieldType)) :-
82		FieldValue = b(_,FieldType,_).