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#!/bin/prolog
% Atoms
x
blue
'Burrito'
'some atom'
camelCaseAtom
% Numbers
1
123123123123
12312.1231
0.1
% Variables
Hello
How_are_you_doing
_amazing
Wow123
% Compound terms
truck_year('Mazda', 1986)
'Person_Friends'(zelda,[tom,jim])
% List
[]
[1,2,3]
[red,green,blue]
% Strings
"to be, or not to be"
"東京都"
% This example was taken from
% http://en.wikipedia.org/wiki/Prolog#Turing_completeness
turing(Tape0, Tape) :-
perform(q0, [], Ls, Tape0, Rs),
reverse(Ls, Ls1),
append(Ls1, Rs, Tape).
/*
*
* This is a multiline comment.
*/
% This is a single-line comment
A is 1. % This is a trailing comment
perform(qf, Ls, Ls, Rs, Rs) :- !.
perform(Q0, Ls0, Ls, Rs0, Rs) :-
symbol(Rs0, Sym, RsRest),
once(rule(Q0, Sym, Q1, NewSym, Action)),
action(Action, Ls0, Ls1, [NewSym|RsRest], Rs1),
perform(Q1, Ls1, Ls, Rs1, Rs).
symbol([], b, []).
symbol([Sym|Rs], Sym, Rs).
action(left, Ls0, Ls, Rs0, Rs) :- left(Ls0, Ls, Rs0, Rs).
action(stay, Ls, Ls, Rs, Rs).
action(right, Ls0, [Sym|Ls0], [Sym|Rs], Rs).
left([], [], Rs0, [b|Rs0]).
left([L|Ls], Ls, Rs, [L|Rs]).
%% Example from pygments
partition([], _, [], []).
partition([X|Xs], Pivot, Smalls, Bigs) :-
( X @< Pivot ->
Smalls = [X|Rest],
partition(Xs, Pivot, Rest, Bigs)
; Bigs = [X|Rest],
partition(Xs, Pivot, Smalls, Rest)
).
quicksort([]) --> [].
quicksort([X|Xs]) -->
{ partition(Xs, X, Smaller, Bigger) },
quicksort(Smaller), [X], quicksort(Bigger).
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