Flee is an expression parser and evaluator for the .NET framework. It allows you to compute the value of string expressions such as sqrt(a^2 + b^2) at runtime. It uses a custom compiler, strongly-typed expression language, and lightweight codegen to compile expressions directly to IL. This means that expression evaluation is extremely fast and efficient. Try out the demo, which lets you generate images based on expressions, and see for yourself.
- Fast and efficient expression evaluation
- Small, lightweight library
- Compiles expressions to IL using a custom compiler, lightweight codegen, and the DynamicMethod class
- Expressions (and the IL generated for them) are garbage-collected when no longer used
- Does not create any dynamic assemblies that stay in memory
- Backed by a comprehensive suite of unit tests
- Culture-sensitive decimal point
- Fine-grained control of what types an expression can use
- Supports all arithmetic operations including the power (^) operator
- Supports string, char, boolean, and floating-point literals
- Supports 32/64 bit, signed/unsigned, and hex integer literals
- Features a true conditional operator
- Supports short-circuited logical operations
- Supports arithmetic, comparison, implicit, and explicit overloaded operators
- Variables of any type can be dynamically defined and used in expressions
- CalculationEngine: Reference other expressions in an expression and recalculate in natural order
- Expressions can index arrays and collections, access fields and properties, and call functions on various types
- Generated IL can be saved to an assembly and viewed with a disassembler
Examples to learn how to create and evaluate expressions. Language Reference for information on the expression language. Frequently Asked Questions about using Flee. Article on CodeProject for a more detailed overview.
Flee is licensed under the LGPL. This means that as long as you dynamically link (ie: add a reference) to the officially released assemblies, you can use it in commercial and non-commercial applications.