error message, not working properly - prolog - prolog

Question

How to repair a program to be ready to be used with SWI Prolog?
Link to source: http://ai-programming.com/prolog_bot_tutorial.htm
chatterbot2:
I modified read_string and write_string to read and write:
knowledge_base([
['WHAT IS YOUR NAME',
['MY NAME IS CHATTERBOT2.',
'YOU CAN CALL ME CHATTERBOT2.',
'WHY DO YOU WANT TO KNOW MY NAME?']
],
['HI',
['HI THERE!',
'HOW ARE YOU?',
'HI!']
],
['HOW ARE YOU',
['I''M DOING FINE!',
'I''M DOING WELL AND YOU?',
'WHY DO YOU WANT TO KNOW HOW AM I DOING?']
],
['WHO ARE YOU',
['I''M AN A.I PROGRAM.',
'I THINK THAT YOU KNOW WHO I''M.',
'WHY ARE YOU ASKING?']
],
['ARE YOU INTELLIGENT',
['YES,OFCORSE.',
'WHAT DO YOU THINK?',
'ACTUALY,I''M VERY INTELLIGENT!']
],
['ARE YOU REAL',
['DOES THAT QUESTION REALLY MATERS TO YOU?',
'WHAT DO YOU MEAN BY THAT?',
'I''M AS REAL AS I CAN BE.']
] ]).
select(0, [H|_], H).
select(N, [_|T], L) :- N > 0, N1 is N - 1, select(N1, T, L).
list_length([], 0).
list_length([_|T], Length):- list_length(T, Length2), Length is Length2 + 1.
quit_session(X):- X = bye,
nl, write('IT WAS NICE TALKING TO YOU USER, SEE YOU NEXT TIME!').
no_response_found(ListOfResponse):-
list_length(ListOfResponse, NumOfResponse),
NumOfResponse == 0,
write('I''M NOT SURE IF I UNDERSTAND WHAT YOU ARE TALKING ABOUT.'), !.
no_response_found(_).
get_keyword(KeyList, [KeyList,_]).
get_response(RespList, [_, RespList]).
select_response(RespList, Response):-
list_length(RespList, NumOfResponse),
IndexOfResponse is integer(random(NumOfResponse)),
select(IndexOfResponse, RespList, Response), !.
select_response(_, _).
find_match(Input, [FirstRecord|RestDatabase], ListOfResponse):-
get_keyword(Keyword, FirstRecord),
Keyword == Input, get_response(ListOfResponse, FirstRecord), !;
find_match(Input, RestDatabase, ListOfResponse).
find_match(_, [_], _).
chatterbot2:-
repeat,
nl, write('>'),
read(Input),
knowledge_base(ListOfRecord),
find_match(Input, ListOfRecord, ListOfResponse),
no_response_found(ListOfResponse),
select_response(ListOfResponse, Response),
write(Response), nl,
quit_session(Input).
When I try to use it I get:
鐀1 ?- chatterbot2.
>hi.
I'M NOT SURE IF I UNDERSTAND WHAT YOU ARE TALKING ABOUT.
ERROR: random/1: Domain error: `not_less_than_one' expected, found `0'
Exception: (7) select_response([], _G492) ? creep
2 ?- chatterbot2.
>'What do you do ?'.
I'M NOT SURE IF I UNDERSTAND WHAT YOU ARE TALKING ABOUT.
ERROR: random/1: Domain error: `not_less_than_one' expected, found `0'
Exception: (7) select_response([], _G485) ? creep
3 ?- chatterbot2.
>'Dog is black'.
I'M NOT SURE IF I UNDERSTAND WHAT YOU ARE TALKING ABOUT.
ERROR: random/1: Domain error: `not_less_than_one' expected, found `0'
Exception: (7) select_response([], _G485) ? creep
4 ?-
EDIT:
With random value =/= 0 :
1 ?- chatterbot2.
>'NOT IN BASE'.
I'M NOT SURE WHAT ARE YOU TALKING ABOUT._G907
is it possible to delete that value of blank arguement _G907 ?> and become only sentence?

Answer 1

Your errors in this particular example are caused by your input. Your input is matched to the first entries in your knowledge_base. Since none of your inputs match, the list that is returned has length 0, causing a problem with the call to random, which seems to need a value of at least 1.
Try 'WHAT IS YOUR NAME' as input for example and see if that works.