c# convert string expression to a boolean expression [closed]

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Is it possible to convert a string expression into a boolean condition?

For example, I get the following string:

var b = "32 < 45 && 32 > 20"

I would like to create a bool expression out of this and invoke it. The string representation is also flexible (to make it more fun), so it allows ||, &&, ().

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Have a look at Flee (Fast Lightweight Expression Evaluator) on CodePlex.

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I would use Irony, the .NET language kit. You could construct a simple grammar with Irony and then parse the string into executable command. There's a decent example of an arthmetic grammar in this tutorial and in the Expression Grammar Sample, its a pretty common request ;)

I definitely suggest using a proper compiler as opposed to Regex or a roll your own approach - it will be much more extensible if you ever want to add more rules.

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If it follows all C# expression rules then compile it as dynamic code as per http://www.west-wind.com/presentations/dynamiccode/dynamiccode.htm

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If you're dealing with relatively simple mathematical expressions then a straightforward implementation of the shunting-yard algorithm should do the trick.

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Take a look at my library, Proviant. It's a .NET Standard library using the Shunting Yard algorithm to evaluate boolean expressions. You could also implement your own grammar.

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I think creating an interpreter for this string would not take too long time.

http://www.industriallogic.com/xp/refactoring/implicitLanguageWithInterpreter.html

here you can find information about design that can be used to create it.

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You could take a look at JINT (Javascript Interpreter for .NET) http://jint.codeplex.com/