falsissime

7 ms·

1.
by falsissime 2y ago
Yes, this technique has been used by several implementations. And any application developer can use `asserta/1` for the very same purpose. Just one rule, that is certainly much more appealing.
2.
by falsissime 2y ago
> The user has no realistic way of implementing the `call/N` builtin themselves. Not sure what you mean by realistic, but `call/1` can be implemented by having one simple rule for each existing predicate (now for the sake of th
3.
by falsissime 3y ago
You lost this bet: Write append3/4 which appends three lists to a fourth, such that append3(Xs,Ys,[e],[]) terminates.
4.
by falsissime 3y ago
For many languages, the lexical part requires an "eager consumer rule"/"maximal munch" in addition to the actual grammar, whereas the remaining grammar does not.
5.
by falsissime 3y ago
> ... all the activity of the early years of logic programming has died out, ... Of course, now there is activity of the current years! What else could we have now? If you look back, there was not only progress but also quite a lot of r
6.
by falsissime 3y ago
> Which system are you referring to? SICStus. The best for catching resource errors (that is with catch/3) and continues thereafter happily. SWI does catch many situations, but as you observe it is much less reliable. SICStus is al
7.
by falsissime 3y ago
> But there's no formal concept of "interface" in Prolog Any predicate you write for someone else has an interface. Someone else includes you in a couple of weeks. All predicates that are not truly auxiliary ones which ar
8.
by falsissime 3y ago
(It seems one needs to go into a post directly to be able to reply more rapidly. The delay seems to be reserved for the thread-mode.) Before sending an e-mail, check https://www.softwarepreservation.org/projects/prolog&
9.
by falsissime 3y ago
Explicit checking of the appropriate instantiations is something for more or less official interfaces, not for every internal predicate. For those official checking via must_be/2, can_be/2 and the library(si) (all in Scryer) is of
10.
by falsissime 3y ago
(It takes some time here, before the reply link appears) While I do not know what you were thinking either, I do know that you insisted on a mode +,- and thus refrained from using the most general query to test your program just in case. Pr
11.
by falsissime 3y ago
Support of as many modes as possible is an aim that is often too ambitious. Instead, unsupported modes should be indicated with an instantiation error or (much rarer) an uninstantiation_error. In this manner the logic remains intact as long
12.
by falsissime 3y ago
For one, the second argument should be (upon success at least) a list. But in your program it isn't a list for `[]`.
13.
by falsissime 3y ago
There is a minor impurity in this code: `N = 1+1, rle([a,a],[[a,N]]).` succeeds, yet `rle([a,a],[[a,N]]), N = 1+1` fails. Add `:- op(150, fx, #).` and use it like `#CountPlus1 #= #Count+1` etc.
14.
by falsissime 4y ago
> but the burning problem that datalog does fix is Prolog's semi-decidability, or in other words, its tendency to enter infinite recursions. Prolog's built-in search is not semidecidable. https://en.wikipedia.org&#x2
15.
by falsissime 4y ago
Any progress for Quantum conformity wise? It's doc reads is a full ISO Prolog implementation https://quantumprolog.sgml.io/docs/langreference.html
16.
by falsissime 4y ago
op(150, fx, #) would make the SWI code more readable.
17.
by falsissime 4y ago
The 1978 DEC10 Prolog user guide mentions PROG.PL as an example of a Prolog file with an extension. See 3.2 in https://userweb.fct.unl.pt/~lmp/publications/online-papers/U... Maybe the 1975 Prolog I manual h
18.
Prolog day – 50 years of Prolog(youtube.com)
4 points by falsissime 4y ago|1 comments
19.
by falsissime 4y ago
Consider to set the flag to "error" to see if there are any cases where infinite terms would be created.
20.
by falsissime 4y ago
> the occurs check is crucial for the performance of the algorithm (because without it unification can go on forever, whereas with the occurs check unification will terminate and find an mgu if one exists). Many current systems perform r
21.
by falsissime 4y ago
Just to note one error in I.2.1: > ... whereas unification without the occur check is linear on the size of the smallest of the terms being unified. This claim is incorrect, it goes far beyond what is possible. To see its incorrectness c
22.
by falsissime 4y ago
> [3] What does the DEC10 Prolog manual say about the occurs check? See I.2.1. Occur Check of https://userweb.fct.unl.pt/~lmp/publications/online-papers/D... A recent related discussion: https:/&#x2F
23.
by falsissime 4y ago
> If Colmerauer had his way, Prolog would be a quick and dirty programming language fit to replace javascript or C. No. There are far too many such allusions in this post that it is difficult to dismantle them all. So I will stick to thi
24.
by falsissime 4y ago
The first Prolog was written in Algol-W. The second one, which was called Prolog I was written in Fortran. See comments for more: https://stackoverflow.com/a/4478969
25.
by falsissime 5y ago
And third, it produces redundant solutions for ground queries.
26.
by falsissime 6y ago
In fact, you can do this with Prolog already, however, you have restrict yourself to the pure monotonic subset. Many parts of Prolog the do not fit can be replaced by purer counterparts. See library(si), library(reif), library(clpz) for su
27.
by falsissime 6y ago
You probably meant The Craft of Prolog by Richard O'Keefe. The preface of the Art of Prolog is about David H. D. Warren's recollections of his first encounters with Prolog.
28.
by falsissime 6y ago
https://www.metalevel.at/prolog/business which is a chapter of the book
29.
by falsissime 6y ago
Or :- use_module(library(clpz)). for its successor which runs with SICStus and Scryer.
30.
by falsissime 6y ago
From the interface (mostly yes, that, is apart from the impure extensions added later, and that chars are used and not codes) it is the same. But from the implementation behind it´s different. In particular from the space requirements. A t

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