isekai_wiki_app/lib/extension/list.dart

import 'package:get/get.dart';

extension ListExtension<T> on List<T> {
  bool addOrSet(int index, T value) {
    if (length == index) {
      add(value);
      return true;
    } else if (length > index) {
      this[index] = value;
      return true;
    }
    return false;
  }

  T getWithSetCallback(int index, T Function() callback) {
    if (length > index) {
      return this[index];
    } else {
      var data = callback();
      addOrSet(index, data);
      return data;
    }
  }
}

extension RxListExtension<T> on RxList<T> {
  bool addOrSet(int index, T value) {
    if (length == index) {
      add(value);
      return true;
    } else if (length > index) {
      this[index] = value;
      return true;
    }
    return false;
  }

  T getWithSetCallback(int index, T Function() callback) {
    if (length > index) {
      return this[index];
    } else {
      var data = callback();
      addOrSet(index, data);
      return data;
    }
  }
}