0.19.0

Moving to this minor version is greatly recommended, since contract sizes and costs are likely to experience 70% decrease or more due to #297

What's Changed

🏕 Features

• Extend assert sum example and ensure determinism among union types by @nielstron in #285
• Copy in right places to avoid reference capturing by @nielstron in #293
• Make binary operations more accessible by @nielstron in #294
• Add support for builtin list slicing by @nielstron in #295
• Improve error messages for union type and make merging stronger by @nielstron in #296
• Remove the need for an explicit statemonad by @nielstron in #297
• Add proper tests for return statements by @nielstron in #302
• Use constant nth field access where possible by @nielstron in #304
• New minor version by @nielstron in #303

🐛 Bug Fixes

• Disallow retyping of variables to incompatible types by @nielstron in #298
  • This patches a slip-through in the typechecker where a function could capture variables of invalid type.

💔 Breaking Changes

Retyping of variables is now allowed anymore (categorically) since #298 . Assertions on a variable type will still factually change the type but can only narrow down the type (thus compatible with the previously declared type) and are hence still allowed.

👒 Dependencies

• Bump black from 23.10.1 to 23.11.0 by @dependabot in #286

Full Changelog: 0.18.1...0.19.0