compile prolog online

Language: Layout:

:- op(900, xfx, '=>').

np => [det, n].
n => [adj, n].
pp => [p, np].
s => [np, vp].
vp => [tv, np].
vp => [vp, pp].
vp => [sv, s].

det => the.
n => cat.
np => robin.
tv => saw.
vp => sneezed.
p => about.

%%%%%%%%%%  Do not modify the code below %%%%%%%%%%%
 
parse(ListOfWords):-
    findall(Tree,parse([],ListOfWords,[],Tree),L),
    nl,write('Parse tree(s): '),nl,
    writeout_l(L), 
    write('Done parsing!').
 
parse([_],[],[X],X).

% Binary branching
 
parse([Y,X|MoreStack],Words,[Z,W|ListNodes],Parse):-
       LHS => [X,Y],
       Node = [LHS,W,Z],
       parse([LHS|MoreStack],Words,[Node|ListNodes],Parse).

% Unary branching

parse([X|Stack],Words,[Z|ListNodes],Parse):-
        LHS => X,
        Node = [LHS,Z],
        parse([LHS|Stack],Words,[Node|ListNodes],Parse).

% Lexicon

parse(Stack,[X|Words],ListNodes,Parse):-
        LHS => X,
        Node = [LHS,X],
        parse([LHS|Stack],Words,[Node|ListNodes],Parse).

% Pretty print
writeout_l([T|L]):-
	writeout(T),
    nl,nl,
     writeout_l(L).

writeout_l([]).

writeout([X,Y]):- 
	write('['),writeout(X),write(' '),
        writeout(Y),write(']'), !.

writeout([X,Y,Z]):- 
	write('['),writeout(X),write(' '),
        writeout(Y),write(' '),writeout(Z),write(']'), !.

writeout(X):- write(X).

[ - ] Show input
Absolute running time: 0.15 sec, cpu time: 0.02 sec, memory peak: 5 Mb, absolute service time: 0.17 sec