A Pair Class in Dart That Inspired Pair From Java

pair

A Pair class in dart that inspired from Pair in java

Features

• Create New Pair
• Transform pair to Map
• Transfor pair to list (if pair has same type between key and value)
• Mutate to other Pair
• Transform to single new type

Getting started

dart pub add pair

Usage

Intialize new pair

import 'package:pair/pair.dart';

void main() {
  var pair = Pair<int, int>(
    1, // key
    2, // value
  );

  print("pair: $pair");
  print("pair.toList(): ${pair.toList}");
  print("pair.toMap(): ${pair.toMap}");

  // transform pair to new value with difference type
  //
  // by passing transform function
  var tranformed = pair.transform(tranformFunction);

  print("transformed pair : $tranformed");

  // mutate pair to another pair
  //
  // by passing mutate function
  var mutated = pair.mutate(mutateFunction<int, int>);

  print("mutated pair : $mutated");

  var reversedPair = pair.reverse;

  print("reversedPair $reversedPair");

  // deserialized pair
  var (a, b) = pair();

  print("deserialized value. a=$a, b=$b");

  // Pair with difference type between key and val
  var pair2 = Pair<String, int>(
    "index", // key
    1, // value
  );
  print("pair $pair2");

  var pairToList =
      pair2.toList; // it will throw because key and value do not have same type
}

int tranformFunction(int a, int b) {
  return a + b;
}

Pair<String, String> mutateFunction<K, V>(K key, V value) {
  return Pair(
    key.toString(),
    value.toString(),
  );
}

Additional information

You can make a pull request to create a new feature or bug fixing

Use this package as a library

Depend on it

Run this command:

With Dart:

 $ dart pub add pair

With Flutter:

 $ flutter pub add pair

This will add a line like this to your package's pubspec.yaml (and run an implicit dart pub get):

dependencies:
  pair: ^0.1.2

Alternatively, your editor might support dart pub get or flutter pub get. Check the docs for your editor to learn more.

Import it

Now in your Dart code, you can use:

import 'package:pair/pair.dart'; 

example/pair_example.dart

// ignore_for_file: unused_local_variable

import 'package:pair/pair.dart';

void main() {
  var pair = Pair<int, int>(
    1, // key
    2, // value
  );

  print("pair: $pair");
  print("pair.toList(): ${pair.toList}");
  print("pair.toMap(): ${pair.toMap}");

  // transform pair to new value with difference type
  //
  // by passing transform function
  var tranformed = pair.transform(tranformFunction);

  print("transformed pair : $tranformed");

  // mutate pair to another pair
  //
  // by passing mutate function
  var mutated = pair.mutate(mutateFunction<int, int>);

  print("mutated pair : $mutated");

  var reversedPair = pair.reverse;

  print("reversedPair $reversedPair");

  // deserialized pair
  var (a, b) = pair();

  print("deserialized value. a=$a, b=$b");

  // Pair with difference type between key and val
  var pair2 = Pair<String, int>(
    "index", // key
    1, // value
  );
  print("pair $pair2");

  var pairToList =
      pair2.toList; // it will throw because key and value do not have same type
}

int tranformFunction(int a, int b) {
  return a + b;
}

Pair<String, String> mutateFunction<K, V>(K key, V value) {
  return Pair(
    key.toString(),
    value.toString(),
  );
} 

Download details:

Author: nandanurseptama

Source: https://github.com/nandanurseptama/dart_pair

#dart #android #flutter