public static string DefaultArgName(Type argType)
{
if (argType.IsArray)
{
return(DefaultArgName(argType.GetElementType()) + "Array");
}
if (EnumerablePolicy.IsEnumerable(argType))
{
var argPrefix = DefaultArgName(EnumerablePolicy.DetermineElementType(argType));
var suffix = argType.GetGenericTypeDefinition().Name.Split('`').First();
return(argPrefix + suffix);
}
var parts = argType.Name.SplitPascalCase().Split(' ');
if (argType.GetTypeInfo().IsInterface&& parts.First() == "I")
{
parts = parts.Skip(1).ToArray();
}
var raw = (parts.First().ToLower() + parts.Skip(1).Join("")).Split('`').First();
return(raw);
}
public static (Delegate func, Type funcType) LambdaTypeFor(Type serviceType, Type concreteType,
ConstructorInfo ctor)
{
var length = ctor.GetParameters().Length;
var openType = _openTypes[length];
var parameters = ctor.GetParameters();
var arguments = new ParameterExpression[parameters.Length];
var ctorParams = new Expression[parameters.Length];
var parameterTypes = new List <Type>();
for (var i = 0; i < parameters.Length; i++)
{
var parameter = parameters[i];
if (parameter.ParameterType.MustBeBuiltWithFunc())
{
arguments[i] = Expression.Parameter(typeof(object));
if (EnumerablePolicy.IsEnumerable(parameter.ParameterType))
{
var elementType = EnumerablePolicy.DetermineElementType(parameter.ParameterType);
var coerceMethod = (parameter.ParameterType.IsArray ? _coerceToArray : _coerceToList)
.MakeGenericMethod(elementType);
ctorParams[i] = Expression.Call(coerceMethod, arguments[i]);
}
else
{
ctorParams[i] = Expression.Convert(arguments[i], parameter.ParameterType);
}
parameterTypes.Add(typeof(object));
}
else
{
ctorParams[i] = arguments[i] = Expression.Parameter(parameter.ParameterType);
parameterTypes.Add(parameter.ParameterType);
}
}
var parameterType = serviceType.MustBeBuiltWithFunc() ? typeof(object) : serviceType;
parameterTypes.Add(parameterType);
var funcType = openType.MakeGenericType(parameterTypes.ToArray());
if (funcType.MustBeBuiltWithFunc())
{
throw new InvalidOperationException(
$"The Func of signature {funcType.NameInCode()} is not publicly accessible for type {serviceType.FullNameInCode()}");
}
var callCtor = Expression.New(ctor, ctorParams);
var lambda = Expression.Lambda(funcType, callCtor, arguments);
const int FastExpressionCompilerParameterLimit = 8;
if (parameterTypes.Count > FastExpressionCompilerParameterLimit)
{
var bigAssFunc = lambda.Compile();
return(bigAssFunc, funcType);
}
var func = lambda.CompileFast();
return(func, funcType);
}