ExpressParser 1.1.0

ExpressionParser

Simple mathematical expression parser capable of generating IL code to speed up calculations. For more info see GitHub repository

Versions log:

[1.1.0] Extension operations

Allows you to define some operations that can be used in expression string like functions: a+c*f(100,a) where f(,) is user-defined operaion. Also allows you to add expressions as extension operation in other expression.

Example:

using ExpressParser;
using ExpressParser.Operations;
using System.Reflection;
using System.Reflection.Emit;

Dictionary<string, ExtensionProvider> extesions = new();
extesions.Add("sqrt", (context, args) => new SqrtOperation(context, args.Single()));
Expression expr = new("sqrt(a)", extesions);
expr.SetArgument("a", 1048576);
expr.Evaluate(); //1024

class SqrtOperation : Operation
{
    private Operation value;
    public SqrtOperation(Expression expression, Operation value) 
        : base(expression) => this.value = value;

    public override double Evaluate() => Math.Sqrt(value.Evaluate());

    private static MethodInfo sqrt = typeof(Math).GetMethod("Sqrt");
    public override void GenerateIL(ILGenerator il)
    {
        value.GenerateIL(il);
        il.Emit(OpCodes.Call, sqrt);
    }

    public override Operation Clone(Expression newExpr) => 
        new SqrtOperation(newExpr, value.Clone());
}

using ExpressParser;
using System.Collections.Generic;

Expression sum = new("3*a+c");
sum.SetArgument("a", 2);
sum.SetArgument("c", 4);
sum.Evaluate(); //10

Dictionary<string, ExtensionProvider> ext = new();
ext.AddExpression("f", sum);

Expression smth = new("a+f(c,5)", ext);
smth.SetArgument("a",10000);
smth.SetArgument("c",100);
smth.Evaluate(); //10305

[1.0.0] First release

First version of library. Features:

• Parse string to expression
• Set arguments of expression
• Evaluate expression
• Compile expression to IL code, evaluate compiled version

Example:

using ExpressParser;

Expression expr = new("(1+1/a)^pow");
expr.SetArgument("a", 2);
expr.SetArgument("pow", 4);
expr.Evaluate(); //5.0625
expr.Compile();
expr.EvaluateIL(); //5.0625