public override void Emit(Type sourceType, Type targetType, CompilationContext context)
{
context.LoadSource(LoadPurpose.Parameter);
context.CurrentType = sourceType;
context.EmitCast(typeof(IEnumerable <>).MakeGenericType(_sourceElementType));
context.LoadTarget(LoadPurpose.Parameter);
context.CurrentType = targetType;
context.EmitCast(typeof(IEnumerable <>).MakeGenericType(_targetElementType));
_invokerBuilder.Emit(context);
}
public override void Emit(Type sourceType, Type targetType, CompilationContext context)
{
var reflectingTargetType = targetType.GetTypeInfo();
context.EmitCast(typeof(IEnumerable <>).MakeGenericType(_sourceElementType));
_invokerBuilder.Emit(context);
if (reflectingTargetType.IsGenericType)
{
var genericTypeDefinition = targetType.GetGenericTypeDefinition();
if (genericTypeDefinition == typeof(IList <>) || genericTypeDefinition == typeof(ICollection <>) || genericTypeDefinition == typeof(IEnumerable <>))
{
context.EmitCast(targetType);
return;
}
}
else if (targetType.IsArray)
{
context.EmitCast(targetType);
return;
}
if (targetType.IsEnumerable(out var targetElementType))
{
var constructor = reflectingTargetType.GetConstructor(new[] { typeof(IEnumerable <>).MakeGenericType(targetElementType) }) ??
reflectingTargetType.GetConstructor(new[] { typeof(IList <>).MakeGenericType(targetElementType) }) ??
reflectingTargetType.GetConstructor(new[] { typeof(ICollection <>).MakeGenericType(targetElementType) }) ??
reflectingTargetType.GetConstructor(new[] { targetElementType.MakeArrayType() });
if (constructor != null)
{
context.EmitCast(constructor.GetParameters()[0].ParameterType);
context.Emit(OpCodes.Newobj, constructor);
context.CurrentType = targetType;
}
else
{
var defaultConstructor = reflectingTargetType.GetConstructor(Type.EmptyTypes);
var addMethod = reflectingTargetType.GetMethods(BindingFlags.Instance | BindingFlags.Public).Where(method =>
{
if (method.Name != "Add")
{
return(false);
}
var parameters = method.GetParameters();
return(parameters.Length == 1 && parameters[0].ParameterType == targetElementType);
}).FirstOrDefault();
if (defaultConstructor != null && addMethod != null)
{
var targetArrayType = targetElementType.MakeArrayType();
var targetArray = context.DeclareLocal(targetArrayType);
var targetInstance = context.DeclareLocal(targetType);
var index = context.DeclareLocal(typeof(int));
context.EmitCast(targetArrayType);
context.Emit(OpCodes.Stloc, targetArray);
context.Emit(OpCodes.Newobj, defaultConstructor);
context.Emit(OpCodes.Stloc, targetInstance);
// var i = 0;
context.Emit(OpCodes.Ldc_I4_0);
context.Emit(OpCodes.Stloc, index);
var labelEnd = context.DefineLabel();
context.Emit(OpCodes.Br_S, labelEnd);
var labelStart = context.DefineLabel();
context.MakeLabel(labelStart);
// target.Add(array[i]);
context.Emit(OpCodes.Ldloc, targetInstance);
context.Emit(OpCodes.Ldloc, targetArray);
context.Emit(OpCodes.Ldloc, index);
var targetElementTypeInfo = targetElementType.GetTypeInfo();
if (targetElementTypeInfo.IsValueType && !targetElementTypeInfo.IsPrimitive)
{
context.Emit(OpCodes.Ldelema, targetElementType);
}
else
{
context.Emit(OpCodes.Ldelem, targetElementType);
}
context.EmitCall(addMethod);
// i++
context.Emit(OpCodes.Ldloc, index);
context.Emit(OpCodes.Ldc_I4_1);
context.Emit(OpCodes.Add);
context.Emit(OpCodes.Stloc, index);
context.MakeLabel(labelEnd);
context.Emit(OpCodes.Ldloc, index);
context.Emit(OpCodes.Ldloc, targetArray);
context.Emit(OpCodes.Ldlen);
context.Emit(OpCodes.Conv_I4);
context.Emit(OpCodes.Blt_S, labelStart);
context.Emit(OpCodes.Ldloc, targetInstance);
context.CurrentType = targetType;
}
}
}
}
