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A Simple Math and Pseudo C# Expression Evaluator in One C# File. Can also execute small C# like scripts


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⚠️ For now, I don't have time to maintain this repository. So if you have PR to fix some bugs. I'll be happy to review and merge it. Otherwise, I will no longer actively develop ExpressionEvaluator. If the current state of the lib do not suite your needs I suggest you look the list of great alternative projects below.

A Simple Math and Pseudo C# Expression Evaluator in One C# File.

And from version 1.2.0 can execute small C# like scripts

It is largely based on and inspired by the following resources this post on stackoverflow, NCalc, C# Operators and C# Statement Keywords


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And with ScriptEvaluate method

  • Small C# like script evaluation (Multi expressions separated by ; )
  • Some conditional and loop blocks keywords (if, while, for, foreach ...)
  • Multi-line (multi expression) Lambda expressions. (Can be use as method See #72 Declare methods in scripts and the doc)


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Reading and resources

I would say every C# evaluation libraries have drawbacks and benefits, ExpressionEvaluator is not an exception so choose wisely (Read docs and licences).

The biggest difference of ExpressionEvaluator is that everything is evaluated on the fly, nothing is compiled or transpile nor in CLR/JIT/IL nor in lambda expressions nor in javascript or other languages stuffs. So it can be slower in some cases (sometimes not) but it also avoid a lot of memory leaks. It is clearly not optimized for big reuse of expressions as the expression is reevaluated every time (Filtering on big dataset for example). It already allow to evaluate some small scripts. If you don't want an another .dll file in your project, you only need to copy one C# file in your project. And it's MIT licence


Expression Evaluator is free and will always be.
But if you want to say thanks for this lib with a donation or small sponsoring here you can :

Thank you anyway for using ExpressionEvaluator