1		:- multifile generate/2.
2		:- multifile shrink/3.
3
4		:- use_module(library(lists),[delete/3]).
5		:- use_module(library(random),[random_member/2]).
6		:- use_module(library(sets),[subset/2]).
7
8		% Options:
9		% small, positive, negative, nozero, between(A,B) none (i.e. []) for any integer
10		% expr for a well-defined ast integer expression,
11		% random to get either an ast integer node or an integer expression
12
13		generate(prob_ast_integer(Options),Value) :-
14		member(expr,Options) , ! ,
15		delete(Options,expr,DOptions) ,
16		% if no definedness is given set to well-defined
17		(member(_-defined,DOptions)
18		-> NOptions = DOptions
19		; NOptions = [well-defined|DOptions]) ,
20		generate(prob_ast_int_expr(NOptions),Value).
21
22		generate(prob_ast_integer(Options),Value) :-
23		\+member(random,Options) , ! ,
24		generate(integer(Options),Gen) ,
25		Value = b(integer(Gen),integer,[]).
26
27		generate(prob_ast_integer(Options),Value) :-
28		% delete random from options to terminate
29		delete(Options,random,NOptions) ,
30		% higher chance to generate expression
31		random(0,10,R) ,
32		(R > 2
33		-> RandomOption = [expr|NOptions]
34		; RandomOption = NOptions) ,
35		generate(prob_ast_integer(RandomOption),Value).
36
37		shrink(prob_ast_integer(_),b(integer(Value),integer,Info),b(integer(Shrunken),integer,Info)) :-
38		shrink(integer(_),Value,Shrunken).
39
40		shrink(prob_ast_integer(_),Value,Shrunken) :-
41		shrink(prob_ast_int_expr,Value,Shrunken).