open_hypergraphs/lax/var/
mod.rs

1//! A higher-level interface for building lax Open Hypergraphs, including helpers to use *rust
2//! operators* like `+`, `&`, etc. to build terms.
3//! Here's an example of using this interface to build a "full adder" circuit.
4//!
5//! ```ignore
6//! fn full_adder(a: Var, b: Var, cin: Var) -> (Var, Var) {
7//!    let a_xor_b = a.clone() ^ b.clone();
8//!    let a_and_b = a & b;
9//!
10//!    (a_xor_b, a_and_b)
11//! }
12//! ```
13//!
14//! This constructs a [`crate::lax::OpenHypergraph`] like the one below, where dashed lines
15//! indicate nodes connected by the quotient map.
16//!
17//! ```text
18//!     ┌──────┐             ┌──────┐
19//! a   │      ├───●╌╌╌╌╌●───┤      │    a ^ b
20//! ●───┤ Var  │             │ XOR  ├───●
21//!     │      ├───●     ●───┤      │
22//!     └──────┘    \   /    └──────┘
23//!                  \ /
24//!                   X
25//!                  / \
26//!     ┌──────┐    /   \    ┌──────┐
27//! b   │      ├───●     ●───┤      │    a & b
28//! ●───┤ Var  │             │ AND  ├───●
29//!     │      ├───●╌╌╌╌╌●───┤      │
30//!     └──────┘   x1    y1  └──────┘
31//! ```
32//!
33//! The purpose of a [`Var`] is to explicitly track variable usage:
34//! each time the var is used in an expression, a new node is created in the underlying
35//! OpenHypergraph, representing a *copy*.
36//! Note however that a [`Var`] correponds to a *hyperedge* rather than a node.
37//!
38//! See `examples/adder.rs` for a comprehensive example, including a definition of a simple
39//! language of simple digital circuits.
40
41mod operators;
42mod var;
43
44pub use operators::*;
45pub use var::*;
open_hypergraphs/lax/var/mod.rs

open_hypergraphs/lax/var/
mod.rs
