1		:- multifile generate/2.
2		:- multifile shrink/3.
3
4		:- use_module(library(random),[random/3]).
5
6		% Options:
7		% size:Length, alph only a-z
8
9		generate(atom(Options),Value) :-
10		% given or random size
11		(member(size:Size,Options)
12		-> Size >= 0
13		; random(1,20,Size)) ,
14		% only alphabetic with no capital letters, else random chars with special signs
15		(member(alph,Options)
16		-> generate(list(between(97,122),[size:Size]),Codes)
17		; generate(list(between(33,127),[size:Size]),Codes)) ,
18		atom_codes(Value,Codes).
19
20		shrink(atom(_),Value,Shrunken) :-
21		atom_codes(Value,CodeList) ,
22		shrink(list,CodeList,ShrunkenList) ,
23		ShrunkenList \= [] ,
24		atom_codes(Shrunken,ShrunkenList).