mraleph

This step by step guide uses issue RegEx: add a way to get the positions of groups #42307 as a concrete example.

Step 0: Ask the team

Ask Dart team before jumping into the implementation. The best place to ask is on the issue tracker, you can also try hackers-dart channel on Flutter Discord or one of the channels on Dart Community discord - but most SDK developers are not on either of them.

Why ask the team?

• They might give you suggestions for the design and implementation
• They might warn you about potential challenges
• They might have tried implementing such feature before, faced unexpected complications and had to back out.

mraleph

class X {
  final int Function() foo;
  const X({this.foo = _defaultFoo});
  
  static int _defaultFoo() => 0;
}

void main() {
  print(const X().foo());

mraleph

// Based on Martin Kustermann's version and adding support for 
// finalization of memory mapped views.
 
import 'dart:ffi';
import 'dart:io';
import 'dart:typed_data';
import 'dart:math' as math;
 
import 'package:ffi/ffi.dart';
 

mraleph

void main() {
  final count = 1000000;
  final names = ['good', 'bad', 'whatever'];
  final tests = [_test1, _test2, _test3];
  final sw = Stopwatch();
  var repeat = 10;
  sw.start();
  while (repeat-- > 0) {
    for (var i = 0; i < tests.length; i++) {
      final name = names[i];

mraleph

+------------------------------------------------------------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------+--------------+
| Library                                                                                  | Method                                                                                                                                                 | Diff (Bytes) |
+------------------------------------------------------------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------+--------------+
| package:gallery/codeviewer/code_segments.dart                                            | CodeSegments.transformationsDemo                                                                                                                    

mraleph

+------------------------------------------------------------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------+--------------+
| Library                                                                                  | Method                                                                                                                                                 | Diff (Bytes) |
+------------------------------------------------------------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------+--------------+
| package:gallery/codeviewer/code_segments.dart                                            | CodeSegments.transformationsDemo                                                                                                                    

mraleph

diff --git a/lib/recase.dart b/lib/recase.dart
index da14cec..42a1251 100644
--- a/lib/recase.dart
+++ b/lib/recase.dart
@@ -1,44 +1,94 @@
+import 'dart:typed_data';
+
 /// An instance of text to be re-cased.
 class ReCase {
-  final RegExp _upperAlphaRegex = new RegExp(r'[A-Z]');

mraleph

First create a hello.dart file with the following content.

void main(List<String> args) {
  print('Hello, World!');
}

Next we precompile this file using PRODUCT AOT compiler (equivalent of running flutter build aot --release).

mraleph

// Copyright (c) 2020, the Dart project authors.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//     * Redistributions of source code must retain the above copyright
//       notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
//       copyright notice, this list of conditions and the following
//       disclaimer in the documentation and/or other materials provided

mraleph

void sayHello() => print('Hello, World!');