From Newsgroup: comp.lang.prolog

Hi,

This is also fun:

% test
test :-
distinct(dump(_)),
fail.
test.

The Dogelog Player has a 100% Prolog implemented hash map,
using only some primitives term_hash/2 and (==)/2. While
SWI-Prolog uses a C code trie for distinct/2.

Problem with a trie, a lot of copying from the key term
into the trie sub keys. Right? Whereas my hash map doesn't
copy anything (decoupling), respectively I have program

sharing (PS) via the heap, since Dogelog Player is
a heap (sic!) Prolog system:

% SWI-Prolog 10.1.1
?- between(1,3,_), random_dump, time(test), fail; true.
% 400,009 inferences, 0.594 CPU in 0.635 seconds (94% CPU, 673699 Lips)
% 400,009 inferences, 0.578 CPU in 0.636 seconds (91% CPU, 691907 Lips)
% 400,009 inferences, 0.562 CPU in 0.640 seconds (88% CPU, 711127 Lips)
% true.

% Dogelog 2.1.6 for Java
?- between(1,3,_), random_dump, time(test), fail; true.
% Zeit 358.544 ms, GC 0.000 ms, Lips 20350 k
% Zeit 346.934 ms, GC 0.000 ms, Lips 21019 k
% Zeit 356.943 ms, GC 0.000 ms, Lips 20434 k
true.

The above is a preview, it uses a new feature of
Dogelog Player frozen compounds, namely pre-
computed hashes. The SWI C Trie overhead could be

also somewhere else, maybe acyclic_term/1 is slow?
I do a similar thing in my code as well, so I am
not comparing oranges with apples, its rather

a comparison apples with apples.

Have Fun!

Bye

Mild Shock schrieb:

Hi,

How would we do a reverse sorted map?

I find in Java:

TreeMap(Comparator<? super K> comparator)
Constructs a new, empty tree map, ordered
according to the given comparator. https://docs.oracle.com/javase/8/docs/api/java/util/TreeMap.html

Or in Dogelog Player:

tree_new(T):
tree_new(T, F):
The predicate succeeds in R with a new red-black tree.
The binary predicate allows specifying a term compare F. https://www.dogelog.ch/typtab/doclet/book/12_lang/05_libraries/03_util/06_tree.html

Here is an example, using the destructive API. But
the same constructor works also for the non-destructive API.

?- tree_new(_T), tree_add(_T, 0rInf, foo),
-a-a tree_add(_T, 0rNaN, bar), tree_pairs(_T, L).
L = [0rNaN-bar, 0rInf-foo].

And now using a comparator modifier, aggregate with a comparator,
as a closure. Some Joy of Higher Order logic programming:

reverse(C, R, X, Y) :- call(C, R, Y, X).

?- tree_new(_T,reverse(compare)), tree_add(_T, 0rInf, foo),
-a-a tree_add(_T, 0rNaN, bar), tree_pairs(_T, L).
L = [0rInf-foo, 0rNaN-bar].

?- tree_new(_T,reverse(reverse(compare))), tree_add(_T, 0rInf, foo),
-a-a tree_add(_T, 0rNaN, bar), tree_pairs(_T, L).
L = [0rNaN-bar, 0rInf-foo].

Just toying around with my new NaNs.

Have Fun!

Bye

Mild Shock schrieb:

Hi,

Functional requirement:

?- Y = g(_,_), X = f(Y,C,D,Y), term_singletons(X, L),
-a-a-a L == [C,D].

?- Y = g(A,X,B), X = f(Y,C,D), term_singletons(X, L),
-a-a-a L == [A,B,C,D].

Non-Functional requirement:

?- member(N,[5,10,15]), time(singletons(N)), fail; true.
% Zeit 1 ms, GC 0 ms, Lips 4046000, Uhr 11.08.2025 01:36
% Zeit 3 ms, GC 0 ms, Lips 1352000, Uhr 11.08.2025 01:36
% Zeit 3 ms, GC 0 ms, Lips 1355333, Uhr 11.08.2025 01:36
true.

Can your Prolog system do that?

P.S.: Benchmark was:

singletons(N) :-
-a-a-a hydra2(N,Y),
-a-a-a between(1,1000,_), term_singletons(Y,_), fail; true.

hydra2(0, _) :- !.
hydra2(N, s(X,X)) :-
-a-a-a M is N-1,
-a-a-a hydra2(M, X).

Bye

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