private static IEnumerable <Expression> GetArrayBounds(Expression source, Type destinationType)
{
var destRank = destinationType.GetArrayRank();
if (!source.Type.IsArray)
{
for (int i = 0; i < destRank - 1; i++)
{
yield return(Expression.Constant(1));
}
yield return(ExpressionEx.CreateCountExpression(source, true));
}
else
{
var srcRank = source.Type.GetArrayRank();
var method = typeof(Array).GetMethod("GetLength", new[] { typeof(int) });
for (int i = srcRank; i < destRank; i++)
{
yield return(Expression.Constant(1));
}
for (int i = 0; i < srcRank; i++)
{
yield return(Expression.Call(source, method, Expression.Constant(i)));
}
}
}
protected override Expression CreateInstantiationExpression(Expression source, Expression destination, CompileArgument arg)
{
var destinationElementType = arg.DestinationType.ExtractCollectionType();
var count = ExpressionEx.CreateCountExpression(source, false);
var listType = arg.DestinationType.GetTypeInfo().IsInterface
? typeof(List <>).MakeGenericType(destinationElementType)
: arg.DestinationType;
if (count == null)
{
return(Expression.New(listType)); //new List<T>()
}
var ctor = (from c in listType.GetConstructors()
let args = c.GetParameters()
where args.Length == 1 && args[0].ParameterType == typeof(int)
select c).FirstOrDefault();
if (ctor == null)
{
return(Expression.New(listType)); //new List<T>()
}
else
{
return(Expression.New(ctor, count)); //new List<T>(count)
}
}
protected override Expression CreateInstantiationExpression(Expression source, Expression?destination, CompileArgument arg)
{
var destinationElementType = arg.DestinationType.ExtractCollectionType();
return(Expression.NewArrayBounds(
destinationElementType,
ExpressionEx.CreateCountExpression(source, true))); //new TDestinationElement[count]
}
protected override Expression CreateInstantiationExpression(Expression source, Expression?destination, CompileArgument arg)
{
var listType = arg.DestinationType;
if (arg.DestinationType.GetTypeInfo().IsInterface)
{
var dict = arg.DestinationType.GetDictionaryType();
if (dict != null)
{
var dictArgs = dict.GetGenericArguments();
listType = typeof(Dictionary <,>).MakeGenericType(dictArgs);
}
else if (arg.DestinationType.IsAssignableFromList())
{
var destinationElementType = arg.DestinationType.ExtractCollectionType();
listType = typeof(List <>).MakeGenericType(destinationElementType);
}
else // if (arg.DestinationType.IsAssignableFromSet())
{
var destinationElementType = arg.DestinationType.ExtractCollectionType();
listType = typeof(HashSet <>).MakeGenericType(destinationElementType);
}
}
var count = ExpressionEx.CreateCountExpression(source, false);
if (count == null)
{
return(Expression.New(listType)); //new List<T>()
}
var ctor = (from c in listType.GetConstructors()
let args = c.GetParameters()
where args.Length == 1 && args[0].ParameterType == typeof(int)
select c).FirstOrDefault();
if (ctor == null)
{
return(Expression.New(listType)); //new List<T>()
}
else
{
return(Expression.New(ctor, count)); //new List<T>(count)
}
}
protected override Expression CreateBlockExpression(Expression source, Expression destination, CompileArgument arg)
{
if (source.Type.IsArray &&
source.Type.GetArrayRank() == 1 &&
source.Type.GetElementType() == destination.Type.GetElementType() &&
source.Type.GetElementType() !.IsPrimitiveKind())
{
//Array.Copy(src, 0, dest, 0, src.Length)
var method = typeof(Array).GetMethod("Copy", new[] { typeof(Array), typeof(int), typeof(Array), typeof(int), typeof(int) });
var len = arg.UseDestinationValue
? Expression.Call(typeof(Math).GetMethod("Min", new[] { typeof(int), typeof(int) }) !,
ExpressionEx.CreateCountExpression(source) !,
ExpressionEx.CreateCountExpression(destination) !)
: ExpressionEx.CreateCountExpression(source);
return(Expression.Call(method !, source, Expression.Constant(0), destination, Expression.Constant(0), len !));
}
return(CreateArraySet(source, destination, arg));
}
protected override Expression TransformSource(Expression source)
{
if (ExpressionEx.CreateCountExpression(source) != null)
{
return(source);
}
var transformed = source;
var elemType = source.Type.ExtractCollectionType();
var type = typeof(IEnumerable <>).MakeGenericType(elemType);
if (!type.IsAssignableFrom(source.Type))
{
var cast = typeof(Enumerable).GetMethod(nameof(Enumerable.Cast)) !
.MakeGenericMethod(elemType);
transformed = Expression.Call(cast, transformed);
}
var toList = typeof(Enumerable).GetMethod(nameof(Enumerable.ToList)) !
.MakeGenericMethod(elemType);
return(Expression.Call(toList, transformed));
}
protected override Expression CreateBlockExpression(Expression source, Expression destination, CompileArgument arg)
{
if (source.Type.IsArray &&
source.Type.GetArrayRank() == destination.Type.GetArrayRank() &&
source.Type.GetElementType() == destination.Type.GetElementType() &&
source.Type.GetElementType().IsPrimitiveKind())
{
//Array.Copy(src, 0, dest, 0, src.Length)
var method = typeof(Array).GetMethod("Copy", new[] { typeof(Array), typeof(int), typeof(Array), typeof(int), typeof(int) });
return(Expression.Call(method, source, Expression.Constant(0), destination, Expression.Constant(0), ExpressionEx.CreateCountExpression(source, true)));
}
else
{
return(CreateArraySet(source, destination, arg));
}
}
