A relational logic programming language embedded in Rust. It started as a yet another
miniKanren, but has already evolved into its own language with miniKanren at its core.
In addition to core miniKanren language, proto-vulcan currently provides support for: * miniKanren-like breadth-first and Prolog-like depth-first search. * Compound types (Example) * Disequality constraints CLP(Tree) * Finite-domain constraints CLP(FD) * Various operators: anyo, conda, condu, onceo, project * Pattern matching: match, matche, matcha, matchu * Writing goals in Rust embedded inline within proto-vulcan * User extension interface
The language is embedded into Rust with macros which parse the language syntax and convert it into Rust. The language looks a lot like Rust, but isn't. For example, fresh variables are presented with Rust closure syntax, and pattern matching looks like Rust match.
```rust extern crate protovulcan; use protovulcan::prelude::*;
fn main() { let query = protovulcanquery!(|q| { conde { q == 1, q == 2, q == 3, } });
for result in query.run() {
println!("q = {}", result.q);
}
}
The example program produces three solutions:
text
q = 1
q = 2
q = 3
```
To embed proto-vulcan in Rust, four macros are used: proto_vulcan!, proto_vulcan_closure!,
proto_vulcan_query!, and lterm!.
proto_vulcan!(<goal>) declares a Proto-vulcan goal, and returns a Rust
variable of type Goal.proto_vulcan_closure!(<goal>) declares a Proto-vulcan goal, and returns a Rust
variable of type Goal. The goal expression is evaluated lazily when the goal
is evaluated. The closure takes ownership of all variables referenced within the closure.proto_vulcan_query!(|a, b, c| { <goal> }) defines a Proto-vulcan query with query-variables
a, b and c. The returned value is a Query-struct, that when run, produces an
iterator that can be used to iterate over valid solutions to the logic program. The iterator
returns a struct with fields named after the query variables.lterm!(<tree-term>) declares a logic tree-term in Rust code, which can be passed to
proto-vulcan program within protovulcan! or protovulcan_query!, or compared with results.Licensed under either of
at your option.
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.