[ENG-3749] type safe vars

[adhami3310]

import reflex as rx

app = rx.App()


class State(rx.State):
    x: rx.Field[bool] = rx.field(False)

    def flip(self):
        self.x = not self.x


@app.add_page
def index():
    return rx.vstack(
        rx.button("Click me", on_click=State.flip),
        rx.text(State.x),
        rx.text(~State.x),
    )

[linear]

ENG-3749 Implement rx.field to improve type hinting at static analysis

[masenf]

Cool 🤯