1		:- multifile generate/2.
2		:- multifile shrink/3.
3
4		:- use_module(library(random),[random_member/2]).
5
6		% list of options:
7		% extension, value (i.e. random value set) to generate a specific type of ast sequence
8		% avl, list for specific type of value sequence
9		% any to generate either sequence or expression
10		% size:Value to limit length of sequence
11
12		generate(prob_ast_seq(Options),Value) :-
13		is_list(Options) ,
14		generate(ground_type,Type) ,
15		generate(prob_ast_seq(Type,Options),Value).
16
17		generate(prob_ast_seq(Type),Value) :-
18		generate(prob_ast_seq(Type,[]),Value).
19
20		generate(prob_ast_seq(Type,Options),Value) :-
21		member(Type,[integer(_),boolean(_),string(_)]) ,
22		Type =.. [InnerType,_] , ! ,
23		( member(extension,Options)
24		-> delete(Options,extension,NOptions) ,
25		gen_type(Type,ast,NType) ,
26		generate(list(NType,NOptions),Set),
27		Value = b(sequence_extension(Set),seq(InnerType),[])
28		; member(avl,Options)
29		-> generate(prob_value_seq(Type,Options),Seq),
30		Value = b(value(Seq),seq(InnerType),[])
31		; member(list,Options)
32		-> generate(prob_value_seq(Type,Options),Set),
33		Value = b(value(Set),seq(InnerType),[])
34		; % any value sequence
35		member(value,Options)
36		-> generate(prob_value_seq(Type,Options),Seq),
37		Value = b(value(Seq),seq(InnerType),[])
38		; % sequence or sequence expression
39		member(any,Options)
40		-> random_member(T,[seq,expr]) ,
41		(T = seq
42		-> generate(ground_type,SeqType) ,
43		generate(prob_ast_seq(SeqType,[]),Value)
44		; generate(prob_ast_seq_expr([well-defined]),Value))
45		; random_member(SeqOption,[[extension|Options],[value|Options]]) ,
46		generate(prob_ast_seq(Type,SeqOption),Value)).
47
48		generate(prob_ast_seq(empty_sequence,_),b(sequence_extension([]),seq(empty),[])).
49
50		% sequence of several sequences
51		generate(prob_ast_seq(SeqTypeOptions,Options),b(Seq,seq(NType),[])) :-
52		SeqTypeOptions =.. [seq,Type|InnerOptions] ,
53		(InnerOptions = [NOptions]
54		-> true
55		; NOptions = InnerOptions) ,
56		(member(size:Size,Options)
57		-> true
58		; random(1,10,Size)) ,
59		length(List,Size) ,
60		( member(list,Options)
61		-> maplist(generate(prob_value_seq(Type,NOptions)),List) ,
62		Seq = value(List)
63		; member(avl,Options)
64		-> maplist(generate(prob_value_seq(Type,NOptions)),List) ,
65		findall(Key-true,member(Key,List),AVLList) ,
66		list_to_avl(AVLList,AVL) ,
67		Seq = value(avl_set(AVL))
68		; maplist(generate(prob_ast_seq(Type,NOptions)),List) ,
69		Seq = sequence_extension(List)) ,
70		% remove options for node type
71		inner_type(seq(Type),_,Outter) ,
72		length(Outter,L) ,
73		nth1(L,Outter,NewInner,NewOutter) ,
74		surround_type(NewInner,NewOutter,NType).
75
76		shrink(prob_ast_seq,Value,Shrunken) :-
77		shrink(prob_ast_seq_expr,Value,Shrunken).