Scopes

In Teisu, you create a lot of objects: Instances, signals, connections, threads, etc. These objects need to be destroyed when you're done with them.

Teisu's scopes allow you to do so with a minimal, clean API. With that said, there are things you need to know:

1. There are two types of scopes: stable and reactive.

   • Stable scopes never rerun.
   • Reactive scopes can rerun.

   root() creates a stable scope under the hood, and effect() and computed() create a reactive scope.

2. An effect cannot be created within a computed object or another effect.

3. Whenever a scope is destroyed, any scope created within that scope is also destroyed.

   It doesn't matter how nested a scope is, it will get cleaned up.

   local flec = teisu.flec
   local effect = teisu.effect
   local root = teisu.root
   
   local count = flec(0)
   
   local destroy = root(function()
       effect(function()
           print(count())
       end)
   end)
   
   while count() < 5 do
       count(function(old)
           return old + 1
       end)
   
       task.wait(1)
   end
   
   destroy() -- destroys the reactive scope created by effect()

4. Reactive scopes don't have to be created underneath a stable scope.

   Effects and computeds can be used anywhere!

   local flec = teisu.flec
   local effect = teisu.effect
   
   local count = flec(0)
   
   effect(function()
       print(count())
   end)
   
   while count() < 5 do
       count(function(old)
           return old + 1
       end)
   
       task.wait(1)
   end

Scopes may seem tricky to understand, but they're designed so that as long as you understand the things mentioned above, you won't have to worry about them.

In the next section, you'll learn how to clean up a scope.