1		% evaluate ProB AST sequence expressions
2
3		% returns indexed avl_set
4		seqint_avl(Expression,avl_set(AVL)) :-
5		seqint(Expression,Value) ,
6		gen_indexed_couple_list(1,Value,CoupleList) ,
7		findall(Key-true,member(Key,CoupleList),AVLList) ,
8		list_to_avl(AVLList,AVL).
9
10		seqint(b(value(Seq),seq(_),_),Seq) :-
11		is_list(Seq).
12
13		seqint(b(value(avl_set(Seq)),seq(_),_),Value) :-
14		avl_to_list(Seq,List) ,
15		findall(Key,member(Key-true,List),Value).
16
17		seqint(b(sequence_extension([Seq]),seq(seq(_)),_),[Value]) :-
18		seqint(Seq,Value).
19
20		seqint(b(sequence_extension(Set),seq(_),_),Value) :-
21		maplist(ast_to_prob_value,Set,Value).
22
23		seqint(b(general_concat(SeqOfSeq),seq(_),_),Value) :-
24		seqint(SeqOfSeq,Temp) ,
25		flatten(Temp,Value).
26
27		seqint(b(front(Seq),seq(_),_),Value) :-
28		seqint(Seq,Temp) ,
29		remove_last(Temp,Value).
30
31		seqint(b(tail(Seq),seq(_),_),Value) :-
32		seqint(Seq,[_|Value]).
33
34		seqint(b(rev(Seq),seq(_),_),Value) :-
35		seqint(Seq,Temp) ,
36		reverse(Temp,Value).
37
38		seqint(b(restrict_front(Seq,RestrictBy),seq(_),_),Value) :-
39		seqint(Seq,Temp) ,
40		int(RestrictBy,RestrictValue) ,
41		get_first_n(Temp,RestrictValue,Value).
42
43		seqint(b(restrict_tail(Seq,RestrictBy),seq(_),_),Value) :-
44		seqint(Seq,Temp) ,
45		int(RestrictBy,RestrictValue) ,
46		rem_first_n(Temp,RestrictValue,Value).
47
48		seqint(b(concat(Seq1,Seq2),seq(_),_),Value) :-
49		seqint(Seq1,ValueSeq1) ,
50		seqint(Seq2,ValueSeq2) ,
51		append(ValueSeq1,ValueSeq2,Value).
52
53		seqint(b(insert_tail(Val,Seq),seq(_),_),Value) :-
54		sint(Val,Insert) ,
55		seqint(Seq,ValueSeq) ,
56		( Insert = true -> NInsert = [pred_true]
57		; Insert = false -> NInsert = [pred_false]
58		; NInsert = [Insert]) ,
59		append(NInsert,ValueSeq,Value).
60
61		seqint(b(insert_front(Seq,Val),seq(_),_),Value) :-
62		sint(Val,Insert) ,
63		seqint(Seq,ValueSeq) ,
64		( Insert = true -> NInsert = [pred_true]
65		; Insert = false -> NInsert = [pred_false]
66		; NInsert = [Insert]) ,
67		append(ValueSeq,NInsert,Value).
68
69		% return the first n elements of a list
70		get_first_n([],_,[]).
71		get_first_n(_,0,[]).
72		get_first_n([H|T],N,[H|NT]) :-
73		N1 is N - 1 ,
74		get_first_n(T,N1,NT).
75
76		% removes the first n elements of a list
77		rem_first_n([],_,[]).
78		rem_first_n(L,0,L).
79		rem_first_n([_|T],N,NL) :-
80		N1 is N - 1 ,
81		rem_first_n(T,N1,NL).