Rust API Reference

oCAS's Rust API uses a layered crate architecture. The top-level ocas crate re-exports all commonly used types and functions through its prelude module, so a single import is all you need:

#![allow(unused)]
fn main() {
use ocas::prelude::*;
}

Module Hierarchy

graph TD
    OC["ocas<br/>top-level entry point + prelude"]
    CORE["ocas-core<br/>Arena, errors, fuel"]
    DOMAIN["ocas-domain<br/>coefficient domains, number theory, algebraic number fields"]
    ATOM["ocas-atom<br/>expression trees, tensors"]
    PARSE["ocas-parse<br/>string parsing"]
    POLY["ocas-poly<br/>polynomials, matrices, Gröbner bases"]
    REWRITE["ocas-rewrite<br/>pattern matching, simplification, rewriting"]
    CALC["ocas-calc<br/>calculus, ODEs, solvers"]
    EVAL["ocas-eval<br/>evaluator, JIT, numeric integration"]

    OC --> CORE
    OC --> DOMAIN
    OC --> ATOM
    OC --> PARSE
    OC --> POLY
    OC --> REWRITE
    OC --> CALC
    OC --> EVAL

    ATOM --> CORE
    ATOM --> DOMAIN
    PARSE --> CORE
    PARSE --> ATOM
    POLY --> CORE
    POLY --> DOMAIN
    REWRITE --> CORE
    REWRITE --> ATOM
    REWRITE --> PARSE
    CALC --> CORE
    CALC --> DOMAIN
    CALC --> ATOM
    CALC --> POLY
    CALC --> REWRITE
    EVAL --> CORE
    EVAL --> ATOM
    EVAL --> DOMAIN

    style OC fill:#4a9eff,stroke:#2d7ad4,color:#fff
    style CORE fill:#6c757d,stroke:#545b62,color:#fff
    style DOMAIN fill:#28a745,stroke:#1e7e34,color:#fff
    style ATOM fill:#17a2b8,stroke:#117a8b,color:#fff
    style PARSE fill:#6f42c1,stroke:#59359a,color:#fff
    style POLY fill:#fd7e14,stroke:#ca6510,color:#fff
    style REWRITE fill:#e83e8c,stroke:#b82d6e,color:#fff
    style CALC fill:#20c997,stroke:#17a085,color:#fff
    style EVAL fill:#ffc107,stroke:#d39e00,color:#333

Prelude Contents

use ocas::prelude::* imports all of the following items. The most commonly used types can also be accessed directly as ocas::TypeName.

Expression Trees

Coefficient Domains

Polynomials

Matrices

Gröbner Bases

Calculus

Solvers

Rewriting & Simplification

Evaluation & JIT

Numeric Integration

Automatic Differentiation

Tensors

Runtime

Feature Flags Quick Reference

Enable optional backends and acceleration features via the features key in Cargo.toml:

[dependencies]
ocas = { version = "0.24", features = ["gmp", "jit"] }

Tip: default = [] — all backends are off by default for maximum portability (including Windows MSVC). Recommended development configuration: features = ["gmp", "jit"].

Subpage Index

Quick Start

use ocas::prelude::*;
use ocas_core::arena::Arena;

fn main() {
    // 1. Create the arena and expression context
    let arena = Arena::new();
    let ctx = AtomArena::new(&arena);

    // 2. Build the expression sin(x)
    let x = ctx.var("x");
    let expr = ctx.fun("sin", &[x]);

    // 3. Differentiate symbolically (diff takes a Symbol as the variable)
    let deriv = diff(&ctx, expr, Symbol::new("x"));
    assert_eq!(deriv.to_string(), "cos(x)");

    // 4. Simplify (an empty rule set keeps the expression unchanged)
    let simplified = simplify(&ctx, expr, &[], 100);
    assert_eq!(simplified.to_string(), "sin(x)");

    println!("d/dx sin(x) = {}", deriv);
}

See Also

• Architecture Overview — overall design and data flow
• Mathematics Overview — background mathematics and learning paths
• Python API Reference — Python bindings
• C/C++ API Reference — C/C++ bindings