MicroExpressionEvaluator

High-Performance C# Logical Expression Parser and Evaluator

MicroExpressionEvaluator is a blazing-fast, lightweight .NET library for parsing and evaluating complex nested logical expressions in C#. Designed for real-time applications, it delivers unparalleled performance with minimal CPU usage, making it perfect for dynamic rule evaluation in financial modeling, gaming logic, automation systems, and more.

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Table of Contents

• Features
• Why MicroExpressionEvaluator?
• Usage
• Examples
• Real-World Applications
• Performance Comparison
• Roadmap
• Contributing

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Features

• Blazing Fast Performance: Executes complex logical expressions with minimal CPU overhead.
• Multi-Type Support: Handles decimal, bool, and string data types.
• Comprehensive Operator Support: Includes logical (||, &&, !) and comparison (==, !=, <, >, <=, >=) operators.
• Nested and Grouped Expressions: Efficiently evaluates expressions with multiple nesting levels and logical groupings.
• Secure and Lightweight: No reliance on regular expressions or scripting engines, reducing security risks and external dependencies.

Why MicroExpressionEvaluator?

MicroExpressionEvaluator significantly outperforms traditional methods:

• Up to 100x Faster Than Regular Expressions: Avoids the overhead of regex-based parsing.
• Up to 1000x Faster Than Scripting Engines: Eliminates latency from external scripting engines like Roslyn or NLua.
• Optimized for Real-Time Applications: Ideal for scenarios requiring instantaneous logic evaluation without compromising accuracy.

Usage

Using MicroExpressionEvaluator is straightforward. Pass your logical expression as a string to the Evaluate method:

using MicroExpressionEvaluator;

bool result = MicroEx.Evaluate("your_logical_expression");

Example

bool result = MicroEx.Evaluate("false != true && !(-0.2 <= 0.1 || \"a\" == \"b\")");
// result will be true

Examples

Valid Expressions

Expression	Output
7 > -7	true
true == true != false	true
(true || true) && false	false
!true == !(true || false)	true
("text123" == "text123") && (7.00000 < 7.00001)	true
10000000000.00000000000 < 10000000000.00000000001	true
(false != true) && ((true || false) || (true == false))	true
(false || (true == (false || (true == (false || true)))))	true

Invalid Expressions

Invalid expressions throw descriptive exceptions:

Expression	Exception Message
(true	Invalid input! ')' expected.
-7 && 7	Invalid input! Operator '&&' can only be applied to operands of type 'bool'.
"text123" == true	Invalid input! Operator '==' can only be applied to operands of type 'string' or 'bool'.

Real-World Applications

• Financial Modeling: Real-time evaluation of complex financial conditions and business rules.
• Game Development: Efficient processing of game logic and AI decision-making.
• Automation Systems: Dynamic decision-making in automated workflows and processes.
• System Monitoring: Rapid validation and enforcement of system configurations and policies.

Performance Comparison

Compared to other tools like NCalc, Jint, NLua, and Roslyn, MicroExpressionEvaluator offers:

• Superior Speed: Outperforms in execution time, making it ideal for performance-critical applications.
• Enhanced Security: Reduces risks by not relying on external scripting engines or regular expressions.
• Lightweight Footprint: Minimal dependencies ensure easy integration and deployment.

Roadmap

Upcoming enhancements:

• Mathematical Operations: Support for arithmetic operators (+, -, *, /, ^, %).
• Extended Data Types: Enhanced handling of various numeric types and collections.
• Custom Functions and Variables: Ability to define custom functions and variables within expressions.

Contributing

We welcome contributions! If you have ideas, suggestions, or encounter any issues, please open an issue or submit a pull request.

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We appreciate your feedback and hope MicroExpressionEvaluator becomes an invaluable tool in your projects!