ExpressionEvaluator

Simple expression evaluator for C#

Getting Started

1. Install via nuget: ExpressionEvaluatorCs https://www.nuget.org/packages/ExpressionEvaluatorCs/
2. Sample code

// Returns 6
var result1 = ExpressionEvaluator.Evaluate("(1 + 2) * 2");

// Returns false
var result2 = ExpressionEvaluator.Evaluate("false and true");

For more samples, see ExpressionEvaluatorTest.cs

Why Use This Library?

• Lightweight. Single DLL < 10kb and no third party library dependencies
• Easy to get started and use
• Customization options
• Supports older .NET Framework versions

.NET Support

• Current Release: .NET Framework 4
• Future release: .NET Core (.NET Standard Library)

Expression Support

• And
• False
• Not
• Or
• True

Operator Support

• <
• >
• <=
• >=
• <>
• =
• +
• -
• *
• /
• %

Options

Specify Return Type

Sample code

// Returns 6
int result1 = ExpressionEvaluator.Evaluate<int>("(1 + 2) * 2");

// Returns false
bool result2 = ExpressionEvaluator.Evaluate<bool>("false and true");

Specify Operator Mapping

Sample code

ExpressionEvaluator.SetOperatorMap(new Dictionary<string, string>
{
    {"and", "&&"},
    {"or", "||"},
    {"<>", "!=" },
    {"not", "!" },
    {"true", "1" },
    {"false", "0" }
});

// Returns false
bool result = ExpressionEvaluator.Evaluate<bool>("0 && !1");

ExpressionEvaluator.SetOperatorMap(new Dictionary<string, string>
{
    {"+", "plus"},
    {"*", "times"},
    {"/", "divideBy"},
});

// Returns 6
int result = ExpressionEvaluator.Evaluate<int>("(1 plus 2) times 2");