Modern C++ Calculator v2.1

A modern, high-performance C++ header-only calculator library for evaluating mathematical expressions. Built with C++17/20 features, this library provides a robust and flexible expression parser that supports variables, functions, comparison/logical operators, conditional expressions, complex numbers, symbolic differentiation, and a REPL interface.

📖 Complete Documentation | 🚀 Quick Start Guide | 📋 API Reference

✨ Key Features

• 🚀 Header-only: Modular design, easy integration
• 🔢 Multiple numeric types: Support for int, float, double, and std::complex<double>
• ⚡ High performance: Optimized expression parsing and evaluation
• 🧮 Comprehensive operations: Arithmetic, bitwise, comparison, logical, and power operations
• 📐 Mathematical functions: 60+ built-in functions (trigonometric, hyperbolic, combinatorics, etc.)
• 🔀 Conditional expressions: Ternary operator support (condition ? true : false)
• 📝 User-defined functions: Define custom functions like f(x) = x^2 + 2*x + 1
• 🔣 Complex numbers: Full complex number arithmetic support
• 📊 Symbolic differentiation: Compute derivatives symbolically
• 💻 REPL interface: Interactive calculator with history support
• 🛡️ Robust error handling: Detailed error messages with position information
• 📏 Operator precedence: Follows standard mathematical precedence rules
• 🔧 Template-based: Type-safe generic implementation
• 🔬 Physics constants: Built-in physical constants (c, G, h, Na, etc.)

🚀 Quick Start

Installation

Simply download and include the header file:

curl -O https://raw.githubusercontent.com/ElementAstro/calculator/main/calculator.hpp

Basic Usage

#include "calculator.hpp"
#include <iostream>

int main() {
    // Simple expression evaluation
    double result = calculator::eval("3 + 4 * 2 / (1 - 5) ** 2");
    std::cout << "Result: " << result << std::endl;  // Output: 3.5

    // Using variables and functions
    calculator::ExpressionParser<double> parser;
    parser.set("x", 5.0);
    parser.set("square", [](double x) { return x * x; });

    double advanced_result = parser.eval("square(x) + 10");
    std::cout << "Advanced result: " << advanced_result << std::endl;  // Output: 35

    return 0;
}

📖 See complete examples and tutorials →

📚 Supported Operations

Category	Operators	Example	Types
Arithmetic	+, -, *, /, %	3 + 4 * 2	All
Floor Division	//	7 // 3 → 2	All
Power	^, **	2^3, 2**3	All
Comparison	>, <, >=, <=, ==, !=	5 > 3	All
Logical	&&, ||, !	(5>3) && (2<4)	All
Bitwise	&, |, ~, <<, >>	5 & 3	int only
Conditional	? :	x > 0 ? x : -x	All
Assignment	=	x = 10	All
Grouping	(, )	(2 + 3) * 4	All

Built-in Functions

Category	Functions
Trigonometric	sin, cos, tan, cot, sec, csc
Inverse Trig	asin, acos, atan, acot, asec, acsc
Hyperbolic	sinh, cosh, tanh, coth, sech, csch
Inverse Hyperbolic	asinh, acosh, atanh
Logarithmic	log, log10, log2, ln, exp, exp2, expm1, log1p
Power/Root	sqrt, cbrt, sqr, cube, pow(x,y), hypot(x,y)
Rounding	floor, ceil, round, trunc, frac, abs
Factorial/Gamma	fact, factorial, gamma, lgamma
Combinatorics	nCr(n,r), nPr(n,r), comb, perm
Number Theory	gcd(a,b), lcm(a,b)
Error Functions	erf, erfc
Utility	sign, heaviside, recip, inv, deg, rad
Two-Argument	max, min, mod, atan2, logb, avg, clamp, wrap

Built-in Constants

Category	Constants
Mathematical	pi, e, phi (golden ratio), tau (2π), sqrt2, sqrt3, ln2, ln10
Special	inf (infinity), nan (not a number)
Physics (SI)	c (speed of light), G (gravitational), h (Planck), kb (Boltzmann), Na (Avogadro), qe (elementary charge)

Advanced Features

• Variables: x = 10 then use x + 5
• User-defined functions: f(x) = x^2 + 2*x + 1 then call f(3)
• Complex numbers: (3 + 4*i) * (1 + 2*i) with std::complex<double>
• Symbolic differentiation: parser.diff("x^2", "x") returns "2 * x"
• REPL interface: Interactive calculator with command history

📋 Complete operator reference and examples →

🎯 Use Cases

• Scientific Computing: Mathematical expression evaluation with variables and functions
• Configuration Systems: Dynamic formula parsing for application settings
• Game Development: Damage calculations, physics formulas, procedural generation
• Financial Applications: Interest calculations, custom metrics, business rules
• Educational Tools: Teaching mathematical concepts and expression evaluation

🔍 See real-world examples →

📖 Documentation

Section	Description
Getting Started	Installation, quick start, and building
User Guide	Comprehensive usage instructions
API Reference	Complete class and function documentation
Examples	Practical code examples and patterns
Reference	Operators, types, and limitations

🔧 Requirements

• C++ Standard: C++17 minimum, C++20 recommended
• Compilers: GCC 8+, Clang 8+, MSVC 19+ (VS 2015+)
• Dependencies: None (header-only, standard library only)
• Platforms: Linux, Windows, macOS, FreeBSD

📄 License

This project is licensed under the MIT License - see the LICENSE file for details.

🤝 Contributing

We welcome contributions! Please see our Contributing Guide for details on how to get started.

• 🐛 Report bugs
• 💡 Request features
• 🔧 Submit pull requests
• 💬 Join discussions

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