CODEWITHSUNDEEP
listrecursionprolog
Cyassin
Cyassin

Reputation: 1490

Building a list in prolog

im a beginner on prolog, and I am trying to return a list of results. Say i have items belonging to a person ie.
items(person1,apple).
items(person1,orange).

I want to be able to create a function that can return the list of items belonging to that person. At the moment I have:

getitems(Person,Result):-items(Person,N),Result is N.

This only returns the first item. How can i get it to return a list of all the items that belong to the person?

Thanks.

Upvotes: 0

Views: 55

Answers (1)

user1812457
user1812457

Reputation:

Asked plenty of times, the correct nomenclature is "Finding all solution to a goal", for example, from the SWI-Prolog implementation, finding all solutions.

In short,

bagof(Item, items(person1, Item), Items).

The predicates in this section, findall, bagof, and setof all behave slightly differently and have their uses. There is plenty of examples on Stackoverflow on how to use each of them.

Upvotes: 1

Related Questions