public static ConfiguredLambdaInfo For(LambdaExpression lambda)
{
var funcArguments = lambda.Parameters.ProjectToArray(p => p.Type);
var contextTypes = GetContextTypes(funcArguments);
var parameterSwapper = ParametersSwapper.For(contextTypes, funcArguments);
return(new ConfiguredLambdaInfo(lambda, contextTypes, lambda.ReturnType, parameterSwapper));
}
public static ConfiguredLambdaInfo For(LambdaExpression lambda)
{
var funcArguments = lambda.Parameters.Select(p => p.Type).ToArray();
var contextTypes = (funcArguments.Length != 1) ? funcArguments : funcArguments[0].GetGenericArguments();
var parameterSwapper = ParametersSwapper.For(contextTypes, funcArguments);
return(new ConfiguredLambdaInfo(lambda, lambda.ReturnType, parameterSwapper));
}
private static ConfiguredLambdaInfo For <T>(
T func,
Type[] contextTypes,
Func <Type[], Type[]> funcArgumentsFactory,
Func <Type[], Type> returnTypeFactory,
params Type[] allowedTypes)
{
var funcType = typeof(T);
if (!funcType.IsGenericType())
{
return(null);
}
var funcTypeDefinition = funcType.GetGenericTypeDefinition();
if (!allowedTypes.Contains(funcTypeDefinition))
{
return(null);
}
var funcTypes = funcType.GetGenericTypeArguments();
var funcArguments = funcArgumentsFactory.Invoke(funcTypes);
var parameterSwapper = ParametersSwapper.For(contextTypes, funcArguments);
if (parameterSwapper == null)
{
return(null);
}
var parameters = funcArguments.ProjectToArray(Parameters.Create);
var valueFactory = func.ToConstantExpression();
var valueFactoryInvocation = Expression.Invoke(valueFactory, parameters.Cast <Expression>());
var valueFactoryLambda = Expression.Lambda(funcType, valueFactoryInvocation, parameters);
return(new ConfiguredLambdaInfo(
valueFactoryLambda,
contextTypes,
returnTypeFactory.Invoke(funcTypes),
parameterSwapper));
}
