This is a talk that I presented at 9th Flutterando Online Meetup, on 2020-04-30.
It was based on a article I published on medium: Dart e Null-safety: uma alternativa funcional
Null-references has been a historical problem. No wonder that Tony Hoare, considered their creator, stated that its existence and usage was the cause of massive losses, maybe to the billion dollars.
Much of the null-references issues can be solved by having a null-safe type system. Therere are many ways to accomplish it. The Dart team decided to implement a new feature called non-null by default, where a type have to be explicitly stated to be nullable.
This presentation deals with two related subjects. (1) How the new non-nullable type system of Dart works, and how it
allow us to write safer code, and (2) how to use the Option monad as an functional alternative to the null using its
map and bind methods as a way of composing functions.
The code presented in the presentation are located at the project directory.
All code and comments are written in english.
In the lib folder within project are all the files used during the presentation. All of them, with exeption of number 1,
requires Dart to use it's experimental feature non-nullable.
The presentation slides are in the slide directory. The slides are written in brazilian portuguese. They have been written
with Beamer through org-mode. Thus, if you want to compile them, you will have to have a working LaTeX and org-mode
environment set up on your system.
The slides are using the metropolis theme. However, the precompile .sty files are present
in the directory, so you won't have to compile by yourself.
The precompiled slides can be found in the releases page.