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CoreCLR-NCalc 3.1.253

NCalc

👁 Build status
👁 NuGet
👁 NuGet

A clone of NCalc from http://ncalc.codeplex.com/ with the following changes:

• added support for .NET Standard 2.0+
• added compilation of expressions to actual CLR lambdas

Installation

Simply install the package via NuGet

PM> Install-Package CoreCLR-NCalc

Creating Lambdas

Simple Expressions

var expr = new Expression("1 + 2");
Func<int> f = expr.ToLambda<int>();
Console.WriteLine(f()); // will print 3

Expressions with Functions and Parameters

class ExpressionContext
{
 public int Param1 { get; set; }
 public string Param2 { get; set; }
 
 public int Foo(int a, int b)
 {
 return a + b;
 }
}

var expr = new Expression("Foo([Param1], 2) = 4 && [Param2] = 'test'");
Func<ExpressionContext, bool> f = expr.ToLambda<ExpressionContext, bool>();

var context = new ExpressionContext { Param1 = 2, Param2 = "test" };
Console.WriteLine(f(context)); // will print True

Performance Comparison

The measurements were done during CI runs on AppVeyor and fluctuate a lot in between runs, but the speedup is consistently in the thousands of percent range. The speedup measured on actual hardware was even higher (between 10,000% and 35,000%).