Write Linq With Eval - Convert string expressions to LINQ expressions dynamically. Supports nullable types, complex expressions, two-parameter lambdas, and comprehensive string operations.
Get Started
$ dotnet add package Linq.EvalReadme
Linq.Eval
Write Linq with Linq.Eval just like writing native C# code and Python eval
Convert string expressions to LINQ expressions dynamically with full support for nullable types, complex operations, and multi-parameter lambdas.
✨ Features
- 🎯 Dynamic Expression Parsing - Convert strings to compiled LINQ expressions
- 🔧 Nullable Type Support - Full support for
??,?.operators - 🧮 Complex Expressions - Nested arithmetic, logical operations, conditionals
- 👥 Multi-Parameter Lambdas - Two-parameter lambda support
- 🔒 Type Safe - Proper Expression Tree type checking
- 🚀 Multi-Framework - Supports .NET 6.0, 7.0, 8.0, 9.0
- ✅ Battle Tested - 970+ passing tests
📦 Installation
dotnet add package Linq.Eval
🚀 Quick Start
using Linq.Eval;
// Simple property access
var expr1 = "(x,y)=>x.Teacher.Age".ToExpression<Func<Student, Teacher, int?>>();
// Conditional expressions
var expr2 = "(x,y)=>x.Teacher.IsPrinciple ? 0 : 100".ToExpression<Func<Student, Teacher, int>>();
// Null-coalescing operator
var expr3 = "(x,y)=>x.Teacher.Age ?? 0".ToExpression<Func<Student, Teacher, int>>();
// Null-conditional operator
var expr4 = "(x,y)=>x.Teacher?.Age".ToExpression<Func<Student, Teacher, int?>>();
// Complex expressions
var expr5 = "(x,y)=>(x.Teacher?.Age ?? 36) > 35 && (x.Age > 10 || !y.IsPrinciple)".ToExpression<Func<Student, Teacher, bool>>();
📚 Advanced Examples
Single Parameter Lambda
// Arithmetic with nullable types
var expr = "x => (x.Salary ?? 0.0) / (double)x.WorkHours > 1000.0"
.ToExpression<Func<Teacher, bool>>();
// String operations
var expr = "x => x.FirstName.Length > 5 && x.LastName.StartsWith(\"S\")"
.ToExpression<Func<Teacher, bool>>();
// Complex nested conditions
var expr = "x => (x.Age ?? 0) > 30 ? (x.Salary ?? 0.0) * 2.0 : (x.Salary ?? 0.0)"
.ToExpression<Func<Teacher, double>>();
Two Parameter Lambda
// Compare two objects
var expr = "(x, y) => (x.Age ?? 0) < (y.Age ?? 0) ? x.Salary : y.Salary"
.ToExpression<Func<Teacher, Teacher, double?>>();
// Mixed type parameters
var expr = "(x, y) => (double)(x.Age ?? 0) > y ? (x.Salary ?? 0.0) : y"
.ToExpression<Func<Teacher, double, double>>();
🎯 What's New in v1.1.0
- ✅ 200+ Bug Fixes - Enhanced nullable type handling and type conversions
- 🧪 172 New Tests - Comprehensive test coverage for edge cases
- 🔧 Improved Type Safety - Better Expression Tree type matching
- 📈 99.6% Test Pass Rate - 968 passing tests across 4 frameworks
See CHANGELOG.md for detailed release notes.
🤝 Contributing
Contributions are welcome! Please feel free to submit a Pull Request.
📄 License
This project is licensed under the MIT License - see the LICENSE file for details.