oso 0.6.0

Major news

Rust support!

Oso now supports applications written in Rust, using our Rust library. Download here.

Breaking changes


This release contains breaking changes. Be sure to follow migration steps before upgrading.

Updated new operator syntax

Previously, the new operator could take one of two forms:

new Foo()

new Foo{}

The former accepted positional arguments, and the latter accepted keyword arguments. In this release, the two forms have combined their powers, and positional and keyword arguments can both be passed via the parenthetical syntax:

new Foo(1, 2, foo: 3, bar: 4)

Keyword arguments must follow positional arguments, and they are not supported in languages that themselves do not support keyword arguments, such as Java and JavaScript (Node.js).

The curly brace syntax (new Foo{}) is no longer valid Polar and will fail to parse.

Migrate to the new constructor syntax by replacing curly braces with parentheses.

Renamed Python error type

The main Python error type is now called OsoError to be more consistent with the other libraries.

Any error handling catching OsoException should be updated to instead catch OsoError.

New features

Keyword arguments now supported in method calls

In languages that support keyword arguments, they may now be passed to method calls using the following syntax:

foo.bar(1, 2, foo: 3, bar: 4)

See Application Field or Method Access.

Other bugs & improvements

  • Java instances may now be unified against other Java instances:

    new Foo() = new Foo()
  • Fixed rule filtering when the input arguments are bound variables. Fixes a performance regression for certain types of policy.

  • The Polar Variable type in Python is now printed as Variable(name).

  • Any rule with a specializer is ordered above a rule without a specializer.

  • Error handling in Python is now more consistent with the other libraries.

django-oso 0.2.0

Bumped the minimum required version of the oso dependency.

flask-oso 0.3.0

Bumped the minimum required version of the oso dependency.

Connect with us on Slack

If you have any questions, or just want to talk something through, jump into Slack. An Oso engineer or one of the thousands of developers in the growing community will be happy to help.