Light

google / gulava Goto Github PK

View Code? Open in Web Editor NEW

41.0 9.0 16.0 515 KB

Relational programming library for Java.

License: MIT License

Java 93.46% Starlark 6.54%

gulava's Introduction

Gulava

Relational programming library for Java.

Gulava allows you to write relational predicates in Java. You can write Prolog-style predicates and use them from normal Java code, seamlessly integrated with the magic of annotation processors.

See the GitHub wiki for some how-tos and to get started writing your own predicates and logic value types.

This repository requires Bazel to build, test, and run. After you have set up Bazel, you can run the demo:

bazel run //java/gulava:Demo

Note that Gulava is not an official Google product.

Contributing

Gulava doesn't have a particular long-term goal in mind besides exploring relational programming. Any contributions to that end are welcome! That could be something like:

New relational programming features, like constraint support.
Interesting demos, like the one in java/gulava/Demo.java but better.
Data structures or other utilities, like java/gulava/util/Queue.java.

Related

MicroKanren paper: http://webyrd.net/scheme-2013/papers/HemannMuKanren2013.pdf

gulava's People

Contributors

Stargazers

Watchers

Forkers

xornand rzs840707 mohamedmaalej kleopatra999 beifengno01 engleangs neotim yaojingguo isabella232 modsbymorgue ghas-results

gulava's Issues

Allow predicates to accept non-logic types and pass them to clauses

It would be nice to be able to pass non-logic types (e.g. int or String) to predicates and let those values pass through to clauses unchanged.

Maybe generic type arguments can be used to indicate equivalent values

Instead of this:

    final Goal order_select(Cons<?, ?> sub, Cons<?, ?> full) {
      return conj(
          same(sub.car(), full.car()),
          order(sub.cdr(), full.cdr()));
    }

It would be nice to write:

    final <A> Goal order_select(Cons<A, ?> sub, Cons<A, ?> full) {
      return order(sub.cdr(), full.cdr());
    }

This could be called an overloading of the meaning of generic type arguments. That's not a bad thing necessarily.

Implement constraints

How constraints could work:

In Subst, store instances of Constraint interface in place of actual values for vars that are constrained
Multiple variables can share the same Constraint, for instance to express (A != 5 || B != 10).
When binding a Var and it has a Constraint assigned to it, verify it is still satisfied. If so, the Constraint can choose to change the Subst and replace itself with a new Constraint, assign new Constraints to different Vars, etc.

Allow clauses to return `void` instead of Goals.UNIT

Instead of:

final Goal order_endOfLists(Void sub, Void full) {
  return UNIT;
}

It would be nice to just write:

final void order_endOfLists(Void sub, Void full) {}

Recommend Projects

React

A declarative, efficient, and flexible JavaScript library for building user interfaces.
Vue.js

🖖 Vue.js is a progressive, incrementally-adoptable JavaScript framework for building UI on the web.
Typescript

TypeScript is a superset of JavaScript that compiles to clean JavaScript output.
TensorFlow

An Open Source Machine Learning Framework for Everyone
Django

The Web framework for perfectionists with deadlines.
Laravel

A PHP framework for web artisans
D3

Bring data to life with SVG, Canvas and HTML. 📊📈🎉

Recommend Topics

javascript

JavaScript (JS) is a lightweight interpreted programming language with first-class functions.
web

Some thing interesting about web. New door for the world.
server

A server is a program made to process requests and deliver data to clients.
Machine learning

Machine learning is a way of modeling and interpreting data that allows a piece of software to respond intelligently.
Visualization

Some thing interesting about visualization, use data art
Game

Some thing interesting about game, make everyone happy.

Recommend Org

Facebook

We are working to build community through open source technology. NB: members must have two-factor auth.
Microsoft

Open source projects and samples from Microsoft.
Google

Google ❤️ Open Source for everyone.
Alibaba

Alibaba Open Source for everyone
D3

Data-Driven Documents codes.
Tencent

China tencent open source team.