4 ms·

While I love null safety, It's hardly a given. For Dart in particular, it sounds like there was a serious discussion about the choice, and it could have gone th

While I love null safety, It's hardly a given. For Dart in particular, it sounds like there was a serious discussion about the choice, and it could have gone the other way. (edit: removed incorrect statement about Python's type safety)

masklinn 4y ago
> languages like Python that don't provide any static type safety https://docs.python.org/3/library/typing.html https://docs.python.org/3/library/typing.html https://github.com/python/mypy https://github.com/python/mypy > let alone null safety https://docs.python.org/3/library/typing.html#typing.Optional https://docs.python.org/3/library/typing.html#typing.Optiona...
- The_Colonel 4y ago
  FWIW my (1 year old) experience with mypy was very poor. Stuff breaking between releases, wrong resolution, bugs. It kinda felt like a 3rd party fun project, not an official high quality solution. The fact that the source can contain completely wrong declarations and Python will happily run it anyway felt really bad. It's kinda like JavaDoc rather than a classic type system.
IshKebab 4y ago
Languages like Java, Go and C were all designed before it became obvious that `Option<>` or `?` were obviously the right thing to do. You can live with it, but most language eventually add some way to deal with it. Java has @NonNull. Javascript and Python both have static type annotations that are non-nullable. Even C++ has some attempt at it (std::option<>). The only one I know of that hasn't bothered trying is Go.
- mrkeen 4y ago
  But the absence of nulls is the feature, not the presence of Option.
  - the_gipsy 4y ago
    Zero-values and pointers-as-options is not even half as good as Option<T>. At best, it was easy to implement, and convenient to use, until you actually had to run the program.
- Quekid5 4y ago
  Go absolutely wasn't. It has been obvious since ML and Haskell.
  - IshKebab 4y ago
    But only to ML and Haskell programmers. Not it is obvious to basically everyone. (Excluding people who just haven't discovered static typing at all yet.)
    - Quekid5 4y ago
      The designers of Go should have known this. It was designed 20-30 years after ML/Haskell.
- pjmlp 4y ago
  C yes, Standard ML was already a thing when Java and Go came to be, and even plenty of other ML derived languages.
munificent 4y ago
> For Dart in particular, it sounds like there was a serious discussion about the choice Yes, we debated it for years. Literally the day we launched, a user filed an issue requesting support for null safety: https://github.com/dart-lang/sdk/issues/22 https://github.com/dart-lang/sdk/issues/22 For most of Dart's history, that was the #1 upvoted issue on the issue tracker. Back in 2011 before I worked directly the language, I proposed null safety: http://journal.stuffwithstuff.com/2011/10/29/a-proposal-for-null-safety-in-dart/ http://journal.stuffwithstuff.com/2011/10/29/a-proposal-for-... I'm immensely glad we finally did it, even though the migration has been a ton of work.

masklinn 4y ago

> languages like Python that don't provide any static type safety https://docs.python.org/3/library/typing.html https://docs.python.org/3/library/typing.html https://github.com/python/mypy https://github.com/python/mypy > let alone null safety https://docs.python.org/3/library/typing.html#typing.Optional https://docs.python.org/3/library/typing.html#typing.Optiona...

The_Colonel 4y ago
FWIW my (1 year old) experience with mypy was very poor. Stuff breaking between releases, wrong resolution, bugs. It kinda felt like a 3rd party fun project, not an official high quality solution. The fact that the source can contain completely wrong declarations and Python will happily run it anyway felt really bad. It's kinda like JavaDoc rather than a classic type system.

IshKebab 4y ago

Languages like Java, Go and C were all designed before it became obvious that `Option<>` or `?` were obviously the right thing to do. You can live with it, but most language eventually add some way to deal with it. Java has @NonNull. Javascript and Python both have static type annotations that are non-nullable. Even C++ has some attempt at it (std::option<>). The only one I know of that hasn't bothered trying is Go.

mrkeen 4y ago
But the absence of nulls is the feature, not the presence of Option.
- the_gipsy 4y ago
  Zero-values and pointers-as-options is not even half as good as Option<T>. At best, it was easy to implement, and convenient to use, until you actually had to run the program.
Quekid5 4y ago
Go absolutely wasn't. It has been obvious since ML and Haskell.
- IshKebab 4y ago
  But only to ML and Haskell programmers. Not it is obvious to basically everyone. (Excluding people who just haven't discovered static typing at all yet.)
  - Quekid5 4y ago
    The designers of Go should have known this. It was designed 20-30 years after ML/Haskell.
pjmlp 4y ago
C yes, Standard ML was already a thing when Java and Go came to be, and even plenty of other ML derived languages.

munificent 4y ago

> For Dart in particular, it sounds like there was a serious discussion about the choice Yes, we debated it for years. Literally the day we launched, a user filed an issue requesting support for null safety: https://github.com/dart-lang/sdk/issues/22 https://github.com/dart-lang/sdk/issues/22 For most of Dart's history, that was the #1 upvoted issue on the issue tracker. Back in 2011 before I worked directly the language, I proposed null safety: http://journal.stuffwithstuff.com/2011/10/29/a-proposal-for-null-safety-in-dart/ http://journal.stuffwithstuff.com/2011/10/29/a-proposal-for-... I'm immensely glad we finally did it, even though the migration has been a ton of work.