Building Expression Trees

The expression tree can be constructed using dynamic type provided by C# programming language or similar feature in other .NET languages. As a result, expression tree looks like a true language expression or statement without method calls such as Property() or Field() for member access.

This feature converts any dynamic expression into expression tree. The starting point is ExpressionBuilder.AsDynamic extension method. After all necessary manipulations with expression tree it is possible to convert dynamic type to Expression type back again.

using DotNext.Linq.Expressions;
using System.Linq.Expressions;

dynamic expr = "Hello, world".Const().AsDynamic();
expr = expr.Length;
Expression e = expr;    //equivalent is "Hello, world".Length
expr = 10L.Const().AsDynamic();
expr = expr + 42L;      //equivalent is 10L + 42L

Unfortunately, due to limitations of C# programming language, construction of new expression or type cast is not available. Delegate invocation expression, method call expression, indexer properties and fields are fully supported.