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The Power of Prolog
101–110 of 164 posts
Re: The Power of Prolog
#102Roughly half the 'power of prolog' comes from the 'power of logic programming' and prolog is by far not the only logic programming language, e.g., - You can do logic programming using minikanren in scheme. (you can also extend the minikanren system if you find a feature missing). - Minikanren was implemented in clojure and called core.logic. - It was also ported to python by Matthew Rocklin I think, called logpy. - T…
> Just try to solve the zebra puzzle [1] (without help if you can, esp. through any of Norvig posts or videos; they're addictive).
FWIW, I generated (using a small Python script) a bunch of zebra puzzles [1] that can be played on the browser, including the original "Einstein's Riddle" [2]
[1] https://www.brainzilla.com/logic/zebra/ [2] https://www.brainzilla.com/logic/zebra/einsteins-riddle/
Re: The Power of Prolog
#103Something I would like to be able to understand/know/study is how logic programming languages are implemented and how their runtime looks like.
Section 4.4 in Structure and Implementation of Computer Programs [1] presents an implementation of a Prolog-like logic programming language in Scheme. It is very instructive to contrast it to the meta-circular evaluator of Scheme in that same book to see the similarities and differences. Paradigms of Artificial Programming by Norvig also contains a chapter implementing Prolog in Common Lisp. The code can be found at…
Here [0] is a video link to SICP lecture 8A about Logic Programming, which accompanies the section 4.4. It's an excellent lecture!
[0] https://ocw.mit.edu/courses/electrical-engineering-and-compu...
Re: The Power of Prolog
#104Roughly half the 'power of prolog' comes from the 'power of logic programming' and prolog is by far not the only logic programming language, e.g., - You can do logic programming using minikanren in scheme. (you can also extend the minikanren system if you find a feature missing). - Minikanren was implemented in clojure and called core.logic. - It was also ported to python by Matthew Rocklin I think, called logpy. - T…
I wonder what the difference is between, say, SWI-Prolog, and a graph database/query system like Neo4J?
Re: The Power of Prolog
#105Roughly half the 'power of prolog' comes from the 'power of logic programming' and prolog is by far not the only logic programming language, e.g., - You can do logic programming using minikanren in scheme. (you can also extend the minikanren system if you find a feature missing). - Minikanren was implemented in clojure and called core.logic. - It was also ported to python by Matthew Rocklin I think, called logpy. - T…
I was surprised by the number of books on CLP at a large public library. It seems that it became the main interest on "logic" programming.
Re: The Power of Prolog
#106Earlier quoted context omitted.
No. This is the standard implementation of the length/2 predicate. Like any other language, prolog has a standard library that includes this predicate. You'd never need to write this in practice, but this is how it would be written in the standard library. In general, any general purpose language worth it's salt will have substantial portions of its standard library written in that language, and in this regard, prolo…
I guess, the point was, if list is a built-in construct, the function length should be also built in. (Unless, that is, natural numbers are defined in the standard library.)
That something is "built in" doesn't mean it won't be defined somewhere, such as in the standard library.
Re: The Power of Prolog
#107Earlier quoted context omitted.
It's no different than: public class LinkedList { ... public int size() { if (head == null) { return 0; } else { int n0 = 1 + head.size(); } } Actually, it is different. In prolog, you don't tell it how to compute an answer. You tell it what the answer is, and it figures out the rest. In the previous example, I'd phrase it more like this: I am sure [] has 0 length. I would be sure [_:Ls] has N length, if I was sure N…
Why on earth doesn't LinkedList already have a size() method? I'm thinking of typed languages, I guess, but surely any sane collection type knows how to perform addition/concatenation with other instances of its own type, right?
Those collections have to be implemented by someone. You seem to be assuming that these collections spring fully formed into the world and are black boxes without an implementation.
Re: The Power of Prolog
#108Never understood why natural numbers (or some set of N) is not in the search space: fib(X,X):- X fib(X,Y1+Y2):- fib(X-1,Y1),fib(X-2,Y2). I tried to get answer to this kwestion in reddit, but all I got was personal insults.
Constraint Programming with finite domains can probably do this.
For example http://mozart.github.io/
Re: The Power of Prolog
#109Roughly half the 'power of prolog' comes from the 'power of logic programming' and prolog is by far not the only logic programming language, e.g., - You can do logic programming using minikanren in scheme. (you can also extend the minikanren system if you find a feature missing). - Minikanren was implemented in clojure and called core.logic. - It was also ported to python by Matthew Rocklin I think, called logpy. - T…
I wonder what the difference is between, say, SWI-Prolog, and a graph database/query system like Neo4J?
Prolog is a turing-complete programming language suitable for general programming tasks. Datalog is a subset of Prolog that is suitable for use as a database/query system. The main difference between datalog and Neo4J is that datalog allows for predicates of arbitrary arity.
Re: The Power of Prolog
#110If you want to exercise your Prolog-foo: https://github.com/norswap/prolog-dry