119 questions
1
vote
0
answers
103
views
Infinite loop with `counto` relation in core.logic
I am interested in expressing the number of occurrences of an element in a list as a relational goal in Clojure's core.logic library.
(Note that this question is not a duplicate of clojure core.logic ...
- 11
0
votes
1
answer
78
views
Clojure core.logic on Finite Domain subtraction not working as expected and not documented
I have written a Clojure program to solve a fairly simple problem. Consider a vector of a fixed size that we need to fill with integers. We must abide by the following rules.
Every integer must be ...
- 1,992
2
votes
2
answers
83
views
why the following clojure core.logic expression returns no solutions? `(run* [a b] (== {:a b} {a :b}))`
Why the first expression (involving maps) doesn't yield any solutions, whereas the second one (involving vectors) does?
(run* [a b] (== {:a b} {a :b}))
;> ()
but
(run* [a b] (== [:a b] [a :b]))
;...
- 2,995
1
vote
2
answers
181
views
how to work with complex data in Clojure edn/map
(def dbSample {
:person [{:person/id 1 :name "dan" :surname "stone" :joindate "01.06.2022" :experience :experience/starter :loyalitylevel :...
- 416
0
votes
3
answers
147
views
How to Extract Clojure string to enumerable of strings?
Suppose I have a simple string that I want to parse into array of string:
"add (multiply (add 1 2) (add 3 4)) (add 5 6)"
How do I parse it into 3 strings (based on outer parentheses):
add
(...
- 886
1
vote
0
answers
143
views
Is it possible to insert a Clojure statement in the middle of a series of core.logic calls, "à la Prolog"?
Prolog mixes logic (fallible) goals, and (infallible) processes like write/2 or assert/1. Is it possible to do so with Clojure's core.logic?
For example:
(pldb/with-db myFacts
(l/run* [x y]
...
- 155
1
vote
1
answer
307
views
passing optional :query-param in clojure request
I have started learning clojure and have one use case where I would want to call a downstream service with query-params. Now these query-params can vary and can be absent. I am stuck at how to ...
- 315
3
votes
1
answer
216
views
Performance characteristics of core.logic with many finite domain constraints
I'm learning relational programming in miniKanren and I decided to implement a time scheduling system. Basically, it boils down to three relations over finite domain.
First, there is a time strip that ...
- 907
1
vote
1
answer
77
views
Extracting finite domain lvars from a map
I want to put fresh lvars with a finite domain into a map, and establish a relationship between them in another part of my code. Consider the snippet below:
(l/run 1 [q]
(l/fresh [x y z a b c]
...
- 907
1
vote
1
answer
113
views
Non-termination when query variable is on a specific position
Consider this blog post where the author implements palindrome relation using reverso:
(defn reverso [l r]
(conde
[(== l ()) (== r ())]
[(fresh [la ld ldr]
(conso la ld l)
(...
- 907
2
votes
1
answer
360
views
How does one simply write an interceptor that extracts json from a get/post request using Pedestal
I am making a simple API That will require to read body parameters from a json/edn request
I am trying to get the program to echo the contents as edn objects but something seems to not work here is my ...
1
vote
0
answers
31
views
Invoke java method that accept variable args from clojure [duplicate]
I have code block in java where I am trying to add customCodecProvider for mongo
(use 'clojure.reflect 'clojure.pprint)
(pprint (reflect org.bson.codecs.configuration.CodecRegistries))
{
:bases #{...
- 829
1
vote
0
answers
86
views
clojure ubergraph compiling error - 'namespace 'ubergraph.core' not found
I have been using ubergraph last few weeks up until this morning, but now am having compiling problem.
In my project.clj's dependencies, ubergraph is declared:
(defproject graph-alg "0.1.0-...
- 23
2
votes
2
answers
1k
views
logic programming - find synonyms of a given word
Task is to write a program that can decide whether two words are synonyms or not.
I have pairs of synonymous words, E.g.:
[big large]
[large huge]
[small little]
We can derive the synonymous ...
- 915
1
vote
0
answers
97
views
Set membership in core.logic without CLP(set) - defne behaviour
As CLP(set) seems to be stuck in the "immediate" roadmap for now 7 years and counting, I'm trying to make an incomplete, inefficient substitute to at least be able to reflect the semantics ...
- 2,441
1
vote
1
answer
140
views
How do I use core.logic to search for valid nested maps in a database of maps?
I'm currently working on a problem that asks to look for certain vendors that can fulfill an order. The vendors are represented as maps, as is the order. A vendor can fulfill an order if it can serve ...
- 11
1
vote
1
answer
243
views
Clojure backward chaining for facts
We are using a forward-chaining rule system where we have to spoon-feed the system the data it needs to make a decision. I'd prefer the rule system can ask the questions to obtain the data needed for ...
- 2,698
4
votes
1
answer
927
views
Is a "facts database" not a core feature of miniKanren?
I have been playing around with miniKanren, trying to understand it by converting very basic Prolog tutorials into it.
I use Python habitually so I started with the LogPy library, which has since been ...
- 34.2k
1
vote
1
answer
398
views
Minimize/maximize possible in clojure / core.logic?
I'm looking for an idiomatic constraint satisfaction solver that can maximize or minimize a goal function, rather than producing a list of matching solutions.
To be precise, I'm more interested in ...
- 165
0
votes
1
answer
65
views
Constrain results from core.logic query?
I am trying to model a graph using core.logic and would like to match all nodes that have edges to two other nodes. I have come up with the below but it returns two results instead of the desired one, ...
- 10.1k
3
votes
1
answer
865
views
Simple Prolog to Clojure core.logic
I've been playing with Prolog recently and getting my head around how to represent some tasks I want to do with it, which are largely about having a database of facts and doing simple queries on it, ...
- 27.5k
0
votes
1
answer
73
views
Prevent symbol call on require in Clojure
So here is my problem,
I have a file sample.clj in namespace abc.xyzin which i am calling db init method directly before doing any CRUD operation.
(db/init some-config)
When i require this ...
2
votes
3
answers
377
views
How does clojure bind variable parameters?
I am a newbie in Clojure.The problem originated when I once checked the source code of conj:
(def conj
(fn ^:static conj
([] [])
([coll] coll)
([coll x] (clojure....
- 143
0
votes
1
answer
74
views
Is there a way to provide hints to the solver, about which paths are better?
Is there a way to prefer certain paths over others during solving? This is really a performance question. When I put all my logic together, it generates 1000’s of solution and this takes exponentially ...
- 823
0
votes
2
answers
235
views
Clojure: How to get an exact answer in a function that calculates the average [duplicate]
How do I get the exact answer instead of just the number / count
I can get the average of a list of numbers, but it will only add the total numbers and divide by the count
(defn aver
[numbers]
...
- 47
0
votes
1
answer
97
views
How to rewrite the core.logic snippet?
I'm trying to rewrite the below piece of core.logic code.
(run* [x y]
(fd/in x (fd/domain 1 2))
(fd/in y (fd/domain 1 2)))
o/p,
([1 1] [2 1] [1 2] [2 2])
I tried the below versions but none ...
- 4,250
2
votes
1
answer
136
views
pseudo-relation in core.logic
In core.logic of function, I see the below definition for clojure.core.logic/everyg.
A pseudo-relation that takes a coll and ensures that the goal g
succeeds on every element of the collection.
...
- 4,250
3
votes
1
answer
117
views
Need clarification in understanding a custom core.logic constraint
I was trying to understand a custom core.logic constraint as defined below,
(defne lefto
"x appears to the left of y in collection l."
[x y l]
([_ _ [x . tail]] (membero y tail))
([_ _ [_ . ...
- 4,250
-1
votes
2
answers
968
views
Can anyone explain me about the sh in clojure in order to execute the system command?
I'm using Mac OS. I want to execute a system command using (use '[clojure.java.shell :only [sh]]), like in How to execute system commands?. I have read https://clojuredocs.org/clojure.java.shell/sh ...
- 11
4
votes
1
answer
297
views
Using apply in core.logic Clojure (CLP) Cryptoarithmetic
(ns verbal-arithmetic
(:require
[clojure.core.logic :refer [all run* everyg lvar == membero fresh conde succeed fail conso resto]]
[clojure.core.logic.fd :as fd]))
(comment
"Solving ...
- 584
3
votes
1
answer
299
views
Clojure core.logic. Can I use complex data-structures in facts and rules?
I'm trying to get to grips with core.logic.
Can I use complex data-structures in facts and rules?
For example, I'm trying to do this :
(pldb/db-rel test a)
(defn is-wibble? [a] (= true (:wibble a)...
- 27.5k
1
vote
1
answer
117
views
Synthesize smallest map satisfying featurec constraints in core.logic?
In core.logic, is there a way to translate the outputs of a program like
(run 2 [q]
(fresh [a]
(featurec q {:foo a})
(membero a '(5))
(conde
((featurec q {:bar 2}))
((...
- 2,134
0
votes
2
answers
205
views
Function not returning (Clojure)
I am new to clojure, my function elligble voters is not returning the vector, where am i going wrong.
(def human-db
[
{:name "Kanishk" :age 28 :sex "male"}
{:name "Kanishk1" :age 29 :sex "...
- 35
0
votes
1
answer
295
views
Debugging a slow performing function in Clojure
I am trying to implement a solution for minimum-swaps required to sort an array in clojure.
The code works, but takes about a second to solve for the 7 element vector, which is very poor compared to ...
- 1,518
3
votes
1
answer
155
views
Correct use of logic languages as a tool
I'm interested in the "use the right tool for the job" philosophy in programming, and I have a problem I thought might be solvable with logic programming. I mean this in a naive way, because I haven't ...
- 41
2
votes
2
answers
356
views
How to write your own simple constraint function in core.logic?
I just read the primer for core.logic. It makes sense so far, but I'm not sure where to go to learn more.
Let's say I wanted to write my own constraint, sort of like the membero shown in the primer. ...
- 16.7k
1
vote
1
answer
125
views
Why does this implementation of sorto does not terminate?
I'm a beginner with logic programming.
I'm trying to implement a sorting relation like this:
(sorto [3 2 1][1 2 3]) -> #s
I'am using clojure and core.logic:
I don't understand why this can ...
- 1,379
1
vote
0
answers
92
views
core.logic incomplete results
I'm struggling with this simple relation, the results are incomplete, and I don't understand why.
I'm beginning with core.logic I don't know if it is a bug or my bad understanding of it.
(...
- 1,379
5
votes
2
answers
1k
views
Does MiniKanren have the "not" operator?
Does MiniKanren have the "not" operator?
For example, how would one represent Prolog's
a :- b, not(c)
a is true if b is true and c is not (Prolog uses negation as failure, i.e. not(c) is considered ...
- 12.7k
3
votes
1
answer
275
views
Is there a logical for-all in clojure.core.logic?
I'm trying to solve the first puzzle in Smullyan's To Mock a Mockingbird using clojure.core.logic, not because it is particularly hard, but rather as an exercise. The puzzle states that there's a ...
- 1,321
4
votes
1
answer
158
views
How to operate on a sequence of lvars
Say I want to get all combinations of bill/coins denominations that amount to a given value, given also a set of available denominations.
So for instance, for (change 14 #{1 2 5 10}) I'd expect
(
...
- 9,811
1
vote
0
answers
72
views
Clojure core.logic conde; quit if condition fails/succeded
does anyone know how to quit / try the next condition in a conde, when a condition fails?
As example:
(run* q (conde
[(conditionA) (conditionB) (conditionC)]
[(conditionA) (conditionD) (...
- 55
0
votes
1
answer
63
views
core.logic explain how `fresh` changes results
Just starting out with core.logic, version "0.8.11":
(q/run* [q]
(q/fresh [a]
(q/membero a [2 3]))
(q/membero q [1]))
I don't understand the result: (1 1).
My understanding is that I ...
- 18.1k
1
vote
1
answer
433
views
what algorithms does clojure's core.logic use for solving? [duplicate]
According to wikipedia, prolog uses SLD Resolution.
What are the principle algorithms driving the solving in core.logic?
- 13.9k
1
vote
1
answer
210
views
Can core.logic be used from Java directly?
Is it possible to gainfully use core.logic from Java code? If so, would greatly appreciate a simple example. If not, could someone point to a pure-Java alternative?
- 1,241
3
votes
1
answer
224
views
core.logic query for string contains
I'm curios if it is possible (and if so how should one implement) something like
string-containso
in core.logic.
an example usage would be something like
(db-rel person x)
(def database
(db
...
- 650
0
votes
2
answers
229
views
Tree search in Clojure core.logic
I've been puzzled by a modelisation problem for some time and I have to confess I have no idea how I could "properly" solve it in core.logic.
It is very easy to state: given a tree (acyclic ...
- 36
4
votes
0
answers
57
views
unexpected behavior in core.logic conjo goal
I have hard time understanding the following behavior of the conjo goal in core.logic.
First, everything seems fine.
(l/run* [q]
(l/conjo q 2 3 [1 2 3] )) => ([1])
The goal succeeds when q = [...
- 2,219
0
votes
1
answer
143
views
How do I model an order relation in core.logic?
I'm trying to model an order relation between a finite set of tasks using core logic. This is what I have so far:
(def tasks [:t0 :t1 :t2])
(defn tasko [x]
(membero x tasks))
(db-rel before-...
- 1,699
1
vote
1
answer
158
views
Using core.logic to make a simple matching function
Suppose we define a relation matches via the following table:
|-----+-----+-----+-----+-----|
| | *A* | *B* | *C* | *D* |
|-----+-----+-----+-----+-----|
| *A* | | X | X | |
|-----+---...
- 7,357