Boolean and Math Expression Parser

Question

I am writing an application that allows a user to enter a boolean expression. I need the ability to evaluate the entered boolean expression at runtime and am looking for both a parser and a expressoin validator.

Parser
The parser needs to take a boolean expression as a string and return true/false.

Example:

string expression = "(1 == 1) && (1 > 0)";
Parser parser = new Parser();
boolean result = parser.parse(expression);  // Result should be True.

In addition to handling boolean expressions I also need it to handle Math.

expression = "((1 + 1 * 2) == 1)";
result = parser.parse(expression);  // Result should be False.

Validate
So that I can tell the user if there is a problem with the expression being entered I also need a way to validate the syntax.

I am working in C# using the .NET Compact Framework, but if you know of something written in another language that may be helpful.

Thanks for any help you can provide. Tom

Answer 1

Our project is using NCalc (with ANTLR underneath for lexing/parsing) and we're very happy with it.

NCalc is a mathematical expressions evaluator in .NET. NCalc can parse any expression and evaluate the result, including static or dynamic parameters and custom functions.

Our application requires that it be cross-compiled for both Full and Compact Frameworks. With relatively simple tweaks we were able to make both NCalc and ANTLR work for both framework flavours.