AlexVegner

python3 -m http.server 8080

python3 -m http.server 8081

AlexVegner

// The Official Standard: RFC 5322 
final emailRegexp = RegExp(
    r"^[a-zA-Z0-9.!#$%&'*+/=?^_`{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,253}[a-zA-Z0-9])?(?:\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,253}[a-zA-Z0-9])?)*$");

void main() {
  [
    'alex.v@gmail.com',
    'v@gmail.com',
    'v@3.gmail.com',
    '@3.gmail.com',

AlexVegner

void main() {
  var now = DateTime.now();
  print(now.toUtc());
}

AlexVegner

import 'dart:async';

main() async {
  print(naturalsTo(10).toList());
  print(await asynchronousNaturalsTo(10).toList());
  print(naturalsDownFrom(10).toList());
  print(await periodicGenerator(10).toList());
}

Iterable<int> naturalsTo(int n) sync* {

AlexVegner

import 'dart:async';

main() async {
  await periodicStreamSample();
//   await streamControllerSample();
//   await streamControllerWithPeriodicEmitsAndWaiterSample();
}

Future<void> periodicStreamSample() async {
  final subscription = Stream.periodic(

AlexVegner

import 'dart:async';

main() async {
  //final version = -1;
  //final version = 0;
  final version = 1;
  
  // use then / catchError
  print('handle with then-catchError');
  checkVersion(version)

AlexVegner

abstract class Cache<T> {
  T getByKey(String key);
  void setByKey(String key, T value);
}

class StringCashe extends Cache<String> {
  var _cache = Map<String, String>();
  @override
  String getByKey(String key) {
    return _cache[key];

AlexVegner

/// Example 1
/// Enum extension
enum NetworkState {
  unknown,
  connected,
  disconnected,
}

/// NetworkStateExtension
extension NetworkStateExt on NetworkState {

AlexVegner

/// class
class Pesron {
  String name; // field
  int age;

  String description() {
    // method
    return '$name, age: $age';
  }
}

AlexVegner

import 'dart:math' as math;

class MyError extends Error {}

class MyException implements Exception {
  MyException([dynamic message]);
}

void checkValue(int value) {
  switch(value) {