act/state

Combining _state functions with do is so common that we have this simple module to make things easier.

If you were previously writing actions like this:

import act.{do}

use state <- do(act.get_state())
use _ <- do(act.set_state("foo"))
use _ <- do(act.update_state(my_update_function))

Using the state module you can write this instead:

import act/state

use state <- state.get()
use <- state.set("foo")
use <- state.update(my_update_function)

Ah, much better! The functions read very nicely and eliminate some visual complexity.

pub fn get(f: fn(a) -> fn(a) -> #(a, b)) -> fn(a) -> #(a, b)

pub fn set(
  state: a,
  f: fn() -> fn(a) -> #(a, b),
) -> fn(a) -> #(a, b)

pub fn update(
  updater: fn(a) -> a,
  f: fn() -> fn(a) -> #(a, b),
) -> fn(a) -> #(a, b)