Ecng.Compilation 1.0.317

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

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