State management without boilerplate by introducing new language features

@jascodes commented on [Sat Jul 13 2019](https://github.com/dart-lang/sdk/issues/37525)

Setting state should be easy and without boiler plate. Check out awesome Svelte 3 feature so fundamental should be built in at compiler level.

Check out https://svelte.dev/examples#reactive-assignments

Svelte 3 is awesome at using simple variables as state which can be used in UI. They do it by using reactive assignments. In order to be complaint with javascript they use `$:` label to mark assignment as reactive(i.e setstate). In dart we can use `<= ` or something else you fancy.

Thx

Start by reading the issue proposal and the linked Svelte 3 reactive-assignments example to understand the requested state-management behavior. Done would require an accepted Dart language and compiler design for reactive assignments, but the issue names no implementation files or tests.

Written by the indexing model from the issue text.