Create Collections from Tlist and TObjectList

[Alexandre Santanna]

Today is possible to create a Collection from an Array, so I can do that:

var SpringList : IList<TPessoa>; DelphiList : TList<TPessoa>; begin DelphiList := TList<TPessoa>.create; DelphiList.Add(TPessoa.create(1, 'ALEXANDRE'));

SpringList := TCollections.CreateList<TPessoa>(DelphiList.ToArray);

Why not create directly from TList?

SpringList := TCollections.CreateList<TPessoa>(DelphiList);

[Stefan Glienke]

I consider adding some overloads to an extension (helper) for TCollections for a next version.

However not on the TCollections from Spring.Collections because of some issue on how the compiler treats overloads of generic methods. That means it produces every overload to a method being called into the dcu including any types - see https://quality.embarcadero.com/browse/RSP-18080

That is why in 1.3 I will remove any dependencies on System.Generics.Collections from any Spring.Collections unit. In a current develop version this already reduces binary bloat and compile time significantly.

[Stefan Glienke]

Here is some example code how to achieve this because currently I am hesitating to add such methods into a new unit and make it complete for all eligible types - so feel free to make your own interop helper to transfer data from existing RTL collections into Spring4D ones:

type
  TCollectionsHelper = class helper for Spring.Collections.TCollections
    class function CreateList<T>(const source: TEnumerable<T>): IList<T>; overload; static;
  end;

class function TCollectionsHelper.CreateList<T>(
  const source: TEnumerable<T>): IList<T>;
var
  item: T;
begin
  Result := TCollections.CreateList<T>;
  for item in source do
    Result.Add(item);
end;