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99 Bottles of Beer/Prolog

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99 Bottles of Beer/Prolog is part of 99 Bottles of Beer. You may find other members of 99 Bottles of Beer at Category:99 Bottles of Beer.
99 Bottles of Beer done in Prolog-languages

Prolog[edit]

Works with: SWI Prolog
bottles(0).
bottles(X):-
writef('%t bottles of beer on the wall \n',[X]),
writef('%t bottles of beer\n',[X]),
write('Take one down, pass it around\n'),
succ(XN,X),
writef('%t bottles of beer on the wall \n\n',[XN]),
bottles(XN).
 
:- bottles(99).

It is possible to extend the previous version so to handle singular and plurals of the word 'bottle':

bottles(0):- write('no more bottles of beer').
bottles(B) :-
dif(B,0), NewB is B - 1,
(
dif(B,1), writef('%t bottles of beer on the wall \n',[B]), writef('%t bottles of beer\n',[B]);
writef('%t bottle of beer on the wall \n',[B]), writef('%t bottle of beer\n',[B])
),
write('Take one down, pass it around\n'),
(
NewB > 1, writef('%t bottles of beer on the wall \n\n',[NewB]);
NewB =:= 1, writef('%t bottle of beer on the wall \n\n',[NewB]);
true
),
bottles(NewB).
 
:- bottles(99).

Another version that handles plural/not plural conditions.

line1(X):- line2(X),write(' on the wall'). 
line2(0):- write('no more bottles of beer').
line2(1):- write('1 bottle of beer').
line2(X):- writef('%t bottles of beer',[X]).
line3(1):- write('Take it down, pass it around').
line3(X):- write('Take one down, pass it around').
line4(X):- line1(X).
 
bottles(0):-!.
bottles(X):-
succ(XN,X),
line1(X),nl,
line2(X),nl,
line3(X),nl,
line4(XN),nl,nl,
!,
bottles(XN).
 
:- bottles(99).

Visual Prolog[edit]

 
implement main
open core, std, console
 
class predicates
bottles : (integer) -> string procedure (i).
 
clauses
bottles(1) = "bottle" :- !.
bottles(_) = "bottles".
 
run():-
init(),
foreach B = downTo(99,1) do
write(B," ",bottles(B), " of beer on the wall,\n"),
write(B," ",bottles(B), " of beer,\n"),
write("Take one down, pass it around,\n"),
write(B-1," ",bottles(B-1)," of beer on the wall.\n\n")
end foreach,
 
succeed().
end implement main
 
goal
mainExe::run(main::run).