Primitive Collections

Primitive collections are intended to be more memory efficient than using an List<Number> to store primitive numbers, because it avoids auto-boxing.

Download

Gradle:

compile 'com.globus-ltd:collections:{latest_release}'

Maven:

<dependency>
  <groupId>com.globus-ltd</groupId>
  <artifactId>collections</artifactId>
  <version>{latest_release}</version>
</dependency>

Usage

IntArrayList and LongArrayList are resizeable-array implementations. These classes are almost equivalents to ArrayList.

Creating an instance and adding elements:

IntArrayList numbers = new IntArrayList();
numbers.add(100);
numbers.add(200); // Now 'numbers' contains 2 elements - 100 and 200
numbers.add(1, 300); // Now 'numbers' contains 3 elements - 100, 300 and 200
numbers.set(2, 400); // Now 'numbers' contains 3 elements - 100, 300 and 400

Copying elements from another instance:

IntArrayList copy = new IntArrayList(numbers); // Changes to copy instance does not affect original object

Iterating over elements:

int size = numbers.size();
for (int i = 0; i < size; i++) {
    int element = numbers.get(i);
    ...
}

Searching for a specified element:

int index = numbers.indexOf(100); 
boolean contains = numbers.contains(100);

Removing the elements:

int removedElement = numbers.removeAt(1); // returns the removed element at index = 1
...
numbers.clear(); // removes all elements from 'numbers', leaving it empty.

Serialization and deserialization:

private IntArrayList numbers;

@Override 
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    if (savedInstanceState != null) {
        numbers = savedInstanceState.getParcelable(KEY_NUMBERS);
    } else {
        numbers = new IntArrayList();
    }
}

...

@Override 
protected void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);
    outState.putParcelable(KEY_NUMBERS, numbers);
}

License

Copyright 2017 Globus Ltd.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.