calc_manager

A Rust port of Microsoft's Windows Calculator CalcManager engine — arbitrary-precision rational arithmetic with full scientific calculator support.

Features

• Arbitrary-precision rational arithmetic — exact p/q representation with configurable display precision
• Zero dependencies — pure Rust, no unsafe, no external crates required at runtime
• Full scientific calculator math:
  • Arithmetic: add, subtract, multiply, divide, remainder, power
  • Exponential/logarithmic: exp, ln, log₁₀, nth root
  • Trigonometric: sin, cos, tan (radians, degrees, gradians)
  • Inverse trig: asin, acos, atan
  • Hyperbolic: sinh, cosh, tanh, asinh, acosh, atanh
  • Factorial via gamma function
  • Bitwise logic: and, or, xor, shifts
  • Base conversion: binary, octal, decimal, hexadecimal
• Cross-platform — builds on Windows, macOS, Linux, iOS, and Android

Quick Start

Add to your Cargo.toml:

[dependencies]
calc_manager = { git = "https://github.com/joshbw/rsCalcManager" }

use calc_manager::ratpack::{Rational, arithmetic::*, constants::RatpackConstants};
use calc_manager::ratpack::exp::{exp_rat, log_rat};
use calc_manager::ratpack::trans::sin_rat;

let precision = 128;
let radix = 10;
let constants = RatpackConstants::new(radix, precision);

// Exact rational arithmetic
let a = Rational::from(355i32);
let b = Rational::from(113i32);
let pi_approx = div_rat(&a, &b, precision).unwrap();

// Transcendental functions
let mut x = Rational::from(1i32);
exp_rat(&mut x, radix, precision, &constants).unwrap();
// x ≈ e ≈ 2.71828...

// Trigonometry (input in radians)
let mut angle = div_rat(&constants.pi, &Rational::from(6i32), precision).unwrap();
sin_rat(&mut angle, radix, precision, &constants).unwrap();
// angle ≈ 0.5

Architecture

Module	Description
ratpack	Arbitrary-precision rational number arithmetic (core math engine)
engine	Calculator state machine and command processing (stub)
manager	High-level calculator manager — mode switching, history, memory (stub)
unit_converter	Unit conversion engine (stub)

The ratpack module is fully ported and tested. It provides the same mathematical operations as the C++ Ratpack library used in Windows Calculator.

Building

cargo build          # Build the library
cargo test           # Run all tests (159 unit + 213 integration + 1 doc)
cargo doc --open     # Generate API documentation

Testing

The test suite includes 373 tests validated against the original C++ implementation:

Category	Tests
Arithmetic	46
Logic (bitwise)	25
Conversion	30
Support (int, frac, gcd)	16
Exp / Log	28
Factorial	15
Trigonometric	29
Inverse Trig	24
Unit tests	159
Doc tests	1

Design Decisions

• No unsafe — all C++ raw pointers replaced with Vec<u32> and owned types
• Result<T, CalcError> — C++ exceptions mapped to Rust Result types
• Automatic memory management — C++ destroynum/destroyrat replaced by Drop
• Trait-based callbacks — C++ virtual interfaces become Rust traits (CalcDisplay, HistoryDisplay)

License

MIT — same as the original Microsoft Calculator source.