Crate canrun

Expand description

Canrun is a logic programming library inspired by the *Kanren family of language DSLs.

Intro blog post: https://esimmler.com/announcing-canrun/
How it works (part 1): https://esimmler.com/building-canrun-part-1/

Status: Exploratory and Highly Experimental

I’m still quite new to both Rust and logic programming, so there are likely to be rough edges. At best it may be a useful implementation of something that resembles the core concepts of a Kanren while being idiomatically Rusty. At worst it may just be a poor misinterpretation with fatal flaws.

Quick Start

use canrun::{LVar, Query};
use canrun::goals::{both, unify};

let x = LVar::new();
let y = LVar::new();
let goal = both(unify(x, y), unify(1, x));

let result: Vec<_> = goal.query(y).collect();

assert_eq!(result, vec![1])

What’s next? Go read a breakdown of this example in the deeper Quick Start explanation.

Re-exports

pub use goals::cmp;

pub use goals::ops;

pub use goals::project;

pub use crate::core::*;

pub use collections::*;

Modules

Unifiable collections with supporting goal functions.

Low level implementation with basic unification, forking and constraint tracking.

Tutorials and other more in-depth documentation (mostly WIP).

Declarative relationships between values.

Macros

Create a goal that only succeeds if all sub-goals succeed.

Create a goal that yields a state for every successful sub-goal.

Create an LMap with automatic key/value Into<Value<T>> wrapping.

Create a tuple of logical values with automatic Into<Value<T>> wrapping.

Create an LVec<T> with automatic Into<Value<T>> conversion.

Structs

A Goal that always fails.

A Goal that always succeeds.

Functions

Create a goal that only succeeds if both sub-goals succeed.

Create a goal that gives access to the underlying State struct.

Create a goal that succeeds if either sub-goal succeed.

Create a goal that is generated via callback just as it is about to be evaluated.

Create a goal that attempts to unify two values with each other.