Ecng.Compilation

Dynamic code compilation infrastructure for C#, F#, and Python. Compile code at runtime, manage references, and cache assemblies.

Overview

This library provides a unified interface for runtime code compilation supporting multiple languages through specialized providers.

Core Types

ICompiler Interface

The main abstraction for compilers.

public interface ICompiler { string Extension { get; } // e.g., ".cs", ".fs", ".py" bool IsAssemblyPersistable { get; } // Can save compiled assembly bool IsTabsSupported { get; } // Language supports tabs bool IsCaseSensitive { get; } // Language is case-sensitive bool IsReferencesSupported { get; } // Supports external references ICompilerContext CreateContext(); Task<CompilationResult> Compile( string name, IEnumerable<string> sources, IEnumerable<(string name, byte[] body)> refs, CancellationToken ct = default); Task<CompilationError[]> Analyse( object analyzer, IEnumerable<object> analyzerSettings, string name, IEnumerable<string> sources, IEnumerable<(string name, byte[] body)> refs, CancellationToken ct = default); }

CompilationResult

Result of a compilation operation.

var result = await compiler.Compile("MyCode", sources, references); if (result.HasErrors) { foreach (var error in result.Errors) { Console.WriteLine($"{error.Type}: {error.Message}"); Console.WriteLine($" Line {error.Line}, Column {error.Column}"); } } else { // Get compiled assembly Assembly assembly = result.Assembly; // Or get as bytes for storage byte[] assemblyBytes = result.AssemblyBytes; }

CompilationError

Represents a compilation error or warning.

public class CompilationError { public CompilationErrorTypes Type { get; } // Error, Warning, Info public string Id { get; } // e.g., "CS0001" public string Message { get; } public int Line { get; } public int Column { get; } }

Reference Types

AssemblyReference

Reference to a .NET assembly.

// From file path var fileRef = new AssemblyReference("path/to/assembly.dll"); // From loaded assembly var loadedRef = new AssemblyReference(typeof(SomeClass).Assembly);

NuGetReference

Reference to a NuGet package.

var nugetRef = new NuGetReference { PackageId = "Newtonsoft.Json", Version = "13.0.1" };

Compiler Provider

Manages available compilers and provides access to them.

// Get registered compilers IEnumerable<ICompiler> compilers = CompilerProvider.Compilers; // Get compiler by extension ICompiler csCompiler = CompilerProvider.GetCompiler(".cs"); ICompiler fsCompiler = CompilerProvider.GetCompiler(".fs"); ICompiler pyCompiler = CompilerProvider.GetCompiler(".py");

Compiler Implementations

Package	Language	Extension
Ecng.Compilation.Roslyn	C#	.cs
Ecng.Compilation.FSharp	F#	.fs
Ecng.Compilation.Python	Python	.py

Expression Formulas

Parse and evaluate mathematical expressions at runtime.

using Ecng.Compilation.Expressions; // Parse expression var formula = ExpressionHelper.Parse("(a + b) * 2"); // Get variables used IEnumerable<string> vars = formula.Variables; // ["a", "b"] // Evaluate with values var values = new Dictionary<string, decimal> { ["a"] = 10, ["b"] = 5 }; decimal result = formula.Calculate(values); // 30

Supported Operations

• Arithmetic: +, -, *, /, %
• Comparison: <, >, <=, >=, ==, !=
• Logical: &&, ||, !
• Functions: abs, sqrt, min, max, pow, etc.

Assembly Load Context

Manage assembly loading for isolation.

using Ecng.Compilation; // Track loaded assemblies var tracker = new AssemblyLoadContextTracker(); // Load assembly in isolated context var context = tracker.CreateContext("MyPlugin"); Assembly asm = context.LoadFromAssemblyPath("plugin.dll"); // Unload when done tracker.Unload("MyPlugin");

Compiler Cache

Cache compiled assemblies for reuse.

public interface ICompilerCache { bool TryGet(string key, out byte[] assembly); void Set(string key, byte[] assembly); void Remove(string key); void Clear(); }

Usage Examples

Compile C# Code

var compiler = CompilerProvider.GetCompiler(".cs"); string code = @" public class Calculator { public int Add(int a, int b) => a + b; }"; var result = await compiler.Compile( name: "Calculator", sources: new[] { code }, refs: Array.Empty<(string, byte[])>()); if (!result.HasErrors) { var type = result.Assembly.GetType("Calculator"); var instance = Activator.CreateInstance(type); var method = type.GetMethod("Add"); int sum = (int)method.Invoke(instance, new object[] { 2, 3 }); Console.WriteLine(sum); // 5 }

Compile with References

var refs = new List<(string, byte[])>(); // Add reference var asmBytes = File.ReadAllBytes("MyLibrary.dll"); refs.Add(("MyLibrary.dll", asmBytes)); var result = await compiler.Compile("MyCode", sources, refs);

NuGet

Install-Package Ecng.Compilation Install-Package Ecng.Compilation.Roslyn # For C# support Install-Package Ecng.Compilation.FSharp # For F# support Install-Package Ecng.Compilation.Python # For Python support