CODEWITHSUNDEEP
listflutterdartgenerics
Vishnubly
Vishnubly

Reputation: 739

Check if an operator is defined for the object in dart

I want to create an extension for a list which would return an in iterable of cumulative values, my approach was like this:-

extension cumulativeList<T> on List<T> {
  Iterable<T> get cumulative {
    T? value;
    return Iterable<T>.generate(this.length, (i) {
      if (value == null) value = this[i];
      else value = value !+ this[i];  //gives and error that operator '+' is not defined for 'Object'
      return value;
    });
  }
}

So is there a way or a workaround to create a generic extension or function something like this, in which we could check if a certain operator is defined on the object?

Upvotes: 0

Views: 82

Answers (1)

Vishnubly
Vishnubly

Reputation: 739

I just needed to extend T with dynamic, so my extension looks like this:-

extension cumulativeList<T extends dynamic> on List<T> {
  Iterable<T> get cumulative {
    T? value;
    return Iterable<T>.generate(this.length, (i) {
      if (value == null) value = this[i];
      else value = value + this[i];
      return value!;
    });
  }
}

Upvotes: 1

Related Questions