Listable class: accessing a class as if it were a list

[Gonzalo Chumillas]

Is there any way to access an instance of a class as if it were a List. I know that when a class extends the IterableBase class, it can be accessed as if it were a collection of values. What I mean:

// ListableBase does not exist, of course
class MyArrayLikeClass extends ListableBase<int> {
   // some code here
}


var myVar = new MyArrayLikeClass();
print(myVar[10]);

[Bob Nystrom]

ListBase<T> in dart:collection is what you want. :)

Cheers!

– bob

On Tue, Jun 21, 2016 at 12:44 PM, Gonzalo Chumillas <gonzalo....@gmail.com> wrote:

Is there any way to access an instance of a class as if it were a List. I know that when a class extends the IterableBase class, it can be accessed as if it were a collection of values. For example:

// ListableBase does not exist, of course
class MyArrayLikeClass extends ListableBase<int> {
   // some code here
}


var myVar = new MyArrayLikeClass();
print(myVar[10]);

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[Lasse R.H. Nielsen]

I'm not sure exactly what you want to achieve. If you just want the index operator, you can implement just that:

   class MyArrayLikeClass {

     operator[](int index) => returnSomeValue(basedOn: index);

     ...

   }

If you want the full List behavior, you can extend ListBase from dart:collection (https://api.dartlang.org/stable/1.17.1/dart-collection/ListBase-class.html)

   class MyArrayLikeClass<T> extends ListBase<T> {

      T operator(int index) => ...;

      int get length => ...

      ...

   }

In that case you have to implement a number of methods (documented in ListBase).

/L

On Tue, Jun 21, 2016 at 9:44 PM, Gonzalo Chumillas <gonzalo....@gmail.com> wrote:

Is there any way to access an instance of a class as if it were a List. I know that when a class extends the IterableBase class, it can be accessed as if it were a collection of values. For example:

// ListableBase does not exist, of course
class MyArrayLikeClass extends ListableBase<int> {
   // some code here
}


var myVar = new MyArrayLikeClass();
print(myVar[10]);

--
For other discussions, see https://groups.google.com/a/dartlang.org/
 
For HOWTO questions, visit http://stackoverflow.com/tags/dart
 
To file a bug report or feature request, go to http://www.dartbug.com/new
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Lasse R.H. Nielsen - l...@google.com  

'Faith without judgement merely degrades the spirit divine'
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[Gonzalo Chumillas]

Thanks. That's what I was looking for.