Skip to main content

Notes from weekly Dart language review

Posted by Bob Nystrom


Here's my notes from this week's meeting. As usual, the meetings are fairly low key as we move towards M1.

Instantiating abstract classes

We're starting to move code from interfaces to abstract classes. We noticed a nasty pattern some people were doing where they made a private factory constructor just to get rid of the default constructor so that a class couldn't be constructed.

We don't want people doing that. So, instead, we'll make it a dynamic error to instantiate an abstract class. (Abstract class meaning a class that defines an abstract method or is explicitly marked "abstract".)

This is already a static warning in the editor, but we will make it an outright error at runtime. If you relied on this behavior, now you'll just override any abstract methods with empty bodies or throws or something.

Kasper pointed out that we can always loosen this up later if the above proves to be problematic.

Markdown doc comments

We've generated a histogram of which markdown features are currently being used in doc comments in the repository. Markdown is so rich that we don't think we can specify everything, so we want to pick just the subset we use.

The plan is that this will be an appendix to the language spec. Specifying this means the Editor can parse doc comments and style them appropriately.

I pointed out that most of the docs in the repo were written before any markdown was supported, so they may not be a representative set. I asked that we also take a look at some of the newer Dart stuff on github, in particular dartlib and the web components stuff.

Cheers!

Popular posts from this blog

Dart in 2016: The fastest growing programming language at Google, 2nd fastest growing in TIOBE Index

Dart was the fastest growing programming language at Google in 2016 with millions of lines of code written. It also made it to TIOBE Index Top 20 this month (see TIOBE's methodology).

It takes time to build something as ambitious as Dart and, in some ways, Dart is still in its infancy. But we're glad the hard work is starting to pay off.

Many thanks to our amazing community!

We're going to celebrate by ... releasing 1.22 next week (as per our usual 6 week release schedule).

The new Google AdSense user interface: built with AngularDart

AdSense is a free, simple way to earn money by placing ads on your website. The team just launched a completely new version of their app for publishers. Read all about it here. We asked Daniel White, the tech lead for the project, some questions because the new UI happens to be built with Dart and Angular2.


AdSense launched way back in 2003. How long is it since the last big redesign?
Last big redesign was called ‘AdSense 3’ and launched about 6 years ago. It was written in Google Web Toolkit (GWT) and the UI has evolved through several iterations - but this is the first ground-up redesign in 6 years. There are a number of long-standing UX issues that we’ve taken the opportunity to solve. A big shout-out to our UX team who’ve been 100% behind this project. We couldn’t have done it without them!

How many software engineers worked on the project?
Purely on the AdSense applications, we have a team of close to 100. Around 25% of them write Dart.

How many lines of code?
We have around 160K LO…

A stronger Dart for everyone

We are constantly asking ourselves:
How do we make developers even more productive when writing Dart apps? We believe that a critical part of the answer to this question is to make strongmode – a sound static type system for Dart – the standard for all Dart developers.

Teams that use Dart to build apps like Soundtrap, AdWords, AdSense, and Greentea say they really enjoy using strong mode features, such as early error detection. In fact, teams that have switched completely to strong mode cite not only early error detection but also better code readability and maintainability as major benefits. We hear this both from small teams and Рeven more so Рfrom large teams with hundreds of developers writing and maintaining millions of lines of Dart code. As Björn Sperber from Soundtrap says,
Strong mode and the smooth integration with IntelliJ is a joy to use and a huge improvement. If you’ve tried out Flutter, you’ve already used strong mode checks from the Dart analyzer.

Given the benefits …