 
:- initialization(play).
play :-
    write('Rock, paper, scissors - shoot!'), nl,
    write('Choose rock (r), paper (p), or scissors (s): '),
    read(PlayerChoice),
    random_choice(ComputerChoice),
    compare_choices(PlayerChoice, ComputerChoice, Result),
    write('You chose '), write_choice(PlayerChoice), nl,
    write('Computer chose '), write_choice(ComputerChoice), nl,
    write(Result), nl.

random_choice(rock).
random_choice(paper).
random_choice(scissors).

compare_choices(PlayerChoice, ComputerChoice, 'Tie') :-
    PlayerChoice = ComputerChoice.

compare_choices(rock, scissors, 'Rock crushes scissors - Player wins!').
compare_choices(scissors, paper, 'Scissors cut paper - Player wins!').
compare_choices(paper, rock, 'Paper covers rock - Player wins!').

compare_choices(scissors, rock, 'Rock crushes scissors - Computer wins!').
compare_choices(paper, scissors, 'Scissors cut paper - Computer wins!').
compare_choices(rock, paper, 'Paper covers rock - Computer wins!').

write_choice(rock) :- write('rock').
write_choice(paper) :- write('paper').
write_choice(scissors) :- write('scissors').

created 2 years ago

Prolog online compiler

Write, Run & Share Prolog code online using OneCompiler’s Prolog online compiler for free. It’s a simple and intuitive platform to experiment with logic programming in Prolog. OneCompiler supports standard Prolog syntax, great for learning, prototyping, and practicing logic-based problems.

About Prolog

Prolog (Programming in Logic) is a logic programming language associated with artificial intelligence and computational linguistics. It works through facts, rules, and queries, using a form of symbolic reasoning known as backward chaining. Prolog is declarative, meaning you describe what you want instead of how to compute it.

Sample Code

The following is a simple Prolog program that prints a greeting:

:- initialization(main).

main :-
    write('Hello, World!').

Syntax Basics

Facts

Facts represent basic assertions about the world.

likes(alice, pizza).
likes(bob, pasta).

Rules

Rules define logical relationships using facts.

friends(X, Y) :- likes(X, Z), likes(Y, Z).

Queries

Queries are used to find information based on facts and rules.

?- likes(alice, What).

Operators

Operator	Description
`:-`	Rule definition
`,`	Logical AND
`;`	Logical OR
`=`	Unification

Lists

member(X, [X|_]).
member(X, [_|T]) :- member(X, T).

Recursion

Prolog heavily relies on recursion.

factorial(0, 1).
factorial(N, F) :-
  N > 0,
  N1 is N - 1,
  factorial(N1, F1),
  F is N * F1.

This guide provides a quick reference to Prolog programming syntax and features. Start writing Prolog code using OneCompiler’s Prolog online compiler today!