xxgreg

import 'dart:convert';
import 'dart:collection';
import 'dart:typed_data';

main() {
  var str = '12345☺';
  var bytes = UTF8.encode(str);
  print(decodeUtf8Slice(bytes, 5, 3));
  print(decodeUtf8Slice(bytes, 5));
  

xxgreg

import 'package:observe/observe.dart';

class ObsTest extends Observable {

  @observable int x;

  void xChanged(c) {
    print('xChanged: $c');
  }

xxgreg

import 'dart:async';
import 'dart:convert';
import 'dart:io';
import 'dart:typed_data';

const SPLIT_SENTINEL = const [42];

class Splitter extends Converter<List<int>, List<List<int>>> {

  Splitter(this._splitOnByte);

xxgreg

import 'dart:async';
import 'dart:chrome';
import 'dart:html';
import 'package:js/js.dart' as js;

void main() {
  var open = new ButtonElement()..text = 'Open';
  document.body.children.add(open);
  
  write(s) => document.body.children.add(new DivElement()..text = s);

xxgreg

Create the files shown below, make sure dart-sdk/bin is in your path and run:

  pub install

This will fetch the source for the postgresql library, and put it in a sub-directory called packages.

Then run the program:

  dart main.dart