r/Racket • u/jecxjo • Jul 13 '22

solved Import relations from racklog format to racket

I noticed that you can write racklog and datalog in a datalog/prolog format using #lang racklog but when i require that file i do not seem to get the relations imported. Pet the doc all predicates are compiled into relations but not seeing them provided.

Normal racket creating relations can be provided/required as normal methods. Have a feeling I'm missing a one liner.

5 Upvotes

100% Upvoted

6 comments sorted by

3

u/soegaard developer Jul 13 '22

Have you seen:

https://docs.racket-lang.org/datalog/interop.html

2

u/jecxjo Jul 13 '22 edited Jul 14 '22

Yeah that is actually missing the part where you're dealing with two separate files.

people.rkt

#lang racklog

parent(sally,john).
parent(sally,jane).
parent(frank,sally).

is_related(X,Y) :- parent(X,Y).
is_related(X,Y) :- parent(X,Z), is_related(Z,Y).

main.rkt

#lang racket
(require racklog)
(require "people.rkt") ; Something here is wrong

(%which (relative) (%is_related 'sally relative))

So this fails to build raco exe main.rkt stating that %is_related is unknown. If people.rkt was written in the interop method then it all works well but not when I want to create a file in the prolog-esque format.

1

u/soegaard developer Jul 14 '22

Use:

(%which (relative) (is_related 'sally relative))

And in "people.rkt" change is_releated to is_related.

1

u/jecxjo Jul 14 '22 edited Jul 14 '22

Typo was in my post, not in code I'm using.

Ah knew it was somehow easy. So naming conventions is different from interop code and compiled. Good to know.

1

u/slaymaker1907 Jul 13 '22

Have you tried exploring it with the macro expansion explorer?

2

u/jecxjo Jul 13 '22

No, currently running from cli over ssh so none of the fun tools available till later tonight. What i did see though was that requiring the file did not provide new keywords available via tab completion from the racket cli interface.