A clone of NCalc from http://ncalc.codeplex.com/ with the following changes:
- added support for CoreCLR (.NET Standard 1.3+)
- embedded portable version of Antlr (no extra library/dependency required)
- added compilation of expressions to actual CLR lambdas
Simply install the package via NuGet
PM> Install-Package CoreCLR-NCalcvar expr = new Expression("1 + 2");
Func<int> f = expr.ToLambda<int>();
Console.WriteLine(f()); // will print 3class 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 TrueThe 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%).
| Formula | Description | Expression Evaluations / sec | Lambda Evaluations / sec | Speedup |
|---|---|---|---|---|
| (4 * 12 / 7) + ((9 * 2) % 8) | Simple Arithmetics | 474,247.87 | 32,691,490.41 | 6,793.33% |
| 5 * 2 = 2 * 5 && (1 / 3.0) * 3 = 1 | Simple Arithmetics | 276,226.31 | 93,222,709.05 | 33,648.67% |
| [Param1] * 7 + [Param2] | Constant Values | 707,493.27 | 21,766,101.47 | 2,976.51% |
| [Param1] * 7 + [Param2] | Dynamic Values | 582,832.10 | 21,400,445.13 | 3,571.80% |
| Foo([Param1] * 7, [Param2]) | Dynamic Values and Function Call | 594,259.69 | 17,209,334.34 | 2,795.93% |