GameDevWare.Dynamic.Expressions 2.2.7

Install-Package GameDevWare.Dynamic.Expressions -Version 2.2.7
dotnet add package GameDevWare.Dynamic.Expressions --version 2.2.7
<PackageReference Include="GameDevWare.Dynamic.Expressions" Version="2.2.7" />
For projects that support PackageReference, copy this XML node into the project file to reference the package.
paket add GameDevWare.Dynamic.Expressions --version 2.2.7
The NuGet Team does not provide support for this client. Please contact its maintainers for support.
#r "nuget: GameDevWare.Dynamic.Expressions, 2.2.7"
#r directive can be used in F# Interactive, C# scripting and .NET Interactive. Copy this into the interactive tool or source code of the script to reference the package.
// Install GameDevWare.Dynamic.Expressions as a Cake Addin
#addin nuget:?package=GameDevWare.Dynamic.Expressions&version=2.2.7

// Install GameDevWare.Dynamic.Expressions as a Cake Tool
#tool nuget:?package=GameDevWare.Dynamic.Expressions&version=2.2.7
The NuGet Team does not provide support for this client. Please contact its maintainers for support.

Actions Status](https://github.com/deniszykov/csharp-eval-unity3d/actions)

Introduction

Attention! This is a paid package, you can use it anywhere if you purchased it.

This package provides the API for parsing and expression execution written in C#. It is specially designed to work with the Unity on various platforms. Since it is written in C# 3.5 and has no additional dependencies, it should work with any version of Unity (and .NET framework).

It is tested to work on:

  • IOS
  • Android
  • WebGL
  • PC/Mac

It should work on any other platforms. For AOT execution platforms (iOS, WebGL) a link.xml should be added to project's root directory. Read more about IL code stripping in official documentation.

API

  • CSharpExpression
    • Evaluate
    • Parse
  • AotCompilation
    • RegisterFunc
    • RegisterForFastCall (optional stuff)

Example

Parsing C# expression into System.Linq.Expression.Expression[T]:

var mathExpr = "Math.Max(x, y)";
var exprTree = CSharpExpression.Parse<double, double, double>(mathExpr, arg1Name: "x", arg2Name: "y") 
// exprTree -> Expression<Func<double, double, double>>

Evaluating C# expression:

var arifExpr = "2 * (2 + 3) << 1 + 1 & 7 | 25 ^ 10";
var result = CSharpExpression.Evaluate<int>(arifExpr); 
// result -> 19

Parser

The parser recognizes the C# 4 grammar only. It includes:

Nullable types are supported. Generics are supported. Enumerations are supported. Type inference is not available and your should always specify generic parameters on types and methods.

Known Types

For security reasons the parser does not provide access to any types except:

  • argument types
  • primitive types
  • Math, Array, Func<> (up to 4 arguments) types

To access other types your should pass typeResolver parameter in Parse and Evaluate method:

var typeResolver = new KnownTypeResolver(typeof(Mathf), typeof(Time));
CSharpExpression.Evaluate<int>("Mathf.Clamp(Time.time, 1.0f, 3.0f)", typeResolver); 

If you want to access all types in UnityEngine you can pass custom AssemblyTypeResolver as typeResolver parameter.

var typeResolver = new AssemblyTypeResolver(typeof(UnityEngine.Application).Assembly);

For security reasons any member invocation on System.Type will throw exceptions until System.Type is added as known type.

AOT Execution

You can compile and evaluate expression created by System.Linq.Expression and execute it in AOT environment where it is usually impossible.

var expr = (Expression<Func<Vector3>>)(() => new Vector3(1.0f, 1.0f, 1.0f));
var fn = expr.CompileAot();

fn; // -> Func<Vector3>
fn(); // -> Vector3(1.0f, 1.0f, 1.0f)

iOS, WebGL and most console platforms use AOT compilation which imposes following restrictions on the dynamic code execution:

  • only Expression<Func<...>> could be used with CompileAot() and Lambda types
  • only static methods using primitives (int, float, string, object ...) are optimized for fast calls
  • all used classes/methods/properties should be visible to Unity's static code analyser
  • ❕ An additional preparation should be made for AOT execution platforms. This link.xml should be added in project's root folder. Read more about IL code stripping in official documentation.

See Also

WebGL and iOS

  • Only Func<> (up to 4 arguments) Lambdas are supported
  • Instance methods invocation performs slowly due reflection
  • Moderate boxing for value types (see roadmap)

You can ensure that your generic Func<> pass AOT compilation by registering it with AotCompilation.RegisterFunc

AotCompilation.RegisterFunc<int, bool>(); // will enable Func<int, bool> lambdas anywhere in expressions

Improving Performance

You can improve the performance of methods invocation by registering their signatures in AotCompilation.RegisterForFastCall().

// Supports up to 3 arguments.
// First generic argument is your class type.
// Last generic argument is return type.

AotCompilation.RegisterForFastCall<InstanceT, ResultT>()
AotCompilation.RegisterForFastCall<InstanceT, Arg1T, ResultT>()
AotCompilation.RegisterForFastCall<InstanceT, Arg1T, Arg2T, ResultT>()
AotCompilation.RegisterForFastCall<InstanceT, Arg1T, Arg2T, Arg3T, ResultT>()

Example:

public class MyVectorMath
{
    public Vector4 Dot(Vector4 vector, Vector4 vector);
    public Vector4 Cross(Vector4 vector, Vector4 vector);
    public Vector4 Scale(Vector4 vector, float scale);    
}

// register Dot and Cross method signatures
AotCompilation.RegisterForFastCall<MyVectorMath, Vector4, Vector4, Vector4>();
// register Scale method signature
AotCompilation.RegisterForFastCall<MyVectorMath, Vector4, float, Vector4>();

Roadmap

You can send suggestions at support@gamedevware.com

  • Expression serialization (in-progress)
  • Void expressions (System.Action delegates) (done)
  • Parser: Delegate construction from method reference
  • Parser: Type inference for generics
  • Parser: Full C#6 syntax
  • Parser: Extension methods
  • Parser: Type initializers, List initializers
  • Custom editor with auto-completion for Unity
  • .NETCoreApp 2.0

    • No dependencies.
  • .NETFramework 3.5

    • No dependencies.
  • .NETFramework 4.5

    • No dependencies.
  • .NETStandard 1.3

NuGet packages

This package is not used by any NuGet packages.

GitHub repositories

This package is not used by any popular GitHub repositories.

Version Downloads Last updated
2.2.7 862 11/29/2020
2.2.6 874 9/15/2019
2.2.5 637 4/20/2019
2.2.4 646 9/3/2018
2.2.2 1,244 5/16/2018
2.2.1 933 12/19/2017
2.2.0 915 11/30/2017
2.1.4 895 10/22/2017
1.0.1.10 963 11/18/2016

# 2.2.7
- added public CSharpExpression.Format method for SyntaxTreeNode
# 2.2.6
- changed order or SyntaxTreeNode fields and added "original C# expression" field to parsed AST.
- refactored C# expression rendering to support null-propagation expressions, type aliases (int, byte, object ...),
- renamed "Render" methods to "FormatAsCSharp". Now it is "formatting"
- moved c# "formatting" methods to CSharpExpression class
- mark old "Parse" functions as errors
- mark old "Render" methods as obsolete
- renamed CSharpExpressionFormatter to CSharpExpressionFormatter
- fixed indexer experssion rendering
- refactored NameUtils to properly render C# type names
# 2.2.5
renamed ParseTreeNode.Lexeme to .Token
renamed few member of TokenType for better clarity
added documentation file in Unity project assets
changed 'propertyOrFieldName' attribute to 'name' in SyntaxTreeNode
renamed PropertyOfFieldBinder to MemberBinder
changed 'PropertyOrField' expression type to 'MemberResolve' in SyntaxTreeNode
added backward compatibility checks in all related classes
# 2.2.4
added protection against wrong expressions like 'a b' which later bound as 'b'
fixed some tokenization errors:
- 'issa'scanned as 'is'[Operator] and 'sa'[Identifier], now as 'issa'
- '.09' scanned as '.'[Operator] and '09'[Number], now as '0.09'
- '0.1x' scanned as '0.1'[Number] and 'x'[Identifier], now cause error
added method call support for numbers (example 1.ToString())
added short number notation (examples '.9' for '0.9')
added '@' prefix for identifiers (example '@is') https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/tokens/verbatim
done small Tokenizer optimization (reduced string allocation during scanning)
# 2.2.3
added ExpressionPacker type. This type allows packing/unpacking expressions into primitive structures (Dictionaries, Arrays...). These structures  could be serialized and wired by network or stored for future use.
added better error message for some binding cases
denying call to 'Type.InvokeMember' if 'Type' is not within 'known types'.
# 2.2.2
* fixed conditional operator (a ? b : c) parsing with method call in place of 'b'
# 2.2.1
* fixed IL2CPP compilation error due _Attribute interface complilation failure
* added few interfaces to AOT.cs file for better AOT coverage
# 2.2.0
Features
* added support for void expressions (Action<> delegates)
* added support of '.NET Standart 1.3' and '.NET Core 2.0' platforms