Helper design validation

[kiyui]

Currently the way patching works is by making the h() function return reducers that will patch widgets stored in the gtkDriver.

As can be seen in #1, even very basic tasks already require custom use-case reducers via overloading a addReducer property in h() and I can imagine a use case for an updateReducer in the future.

Validations required:

• Is the current reducer pattern valid at all?
• Is the current widgets and widgetsProxy storage in gtkDriver robust enough to handle potential issues in the future?
• Should I develop custom helpers such as StackSidebar that handle all the custom reducers that may be required?
• Is the data passed to the patch function sufficient for a higher-order helper to infer how it should patch the widgets?

[kiyui]

Reducer approach (make current code more efficient):

• Use a make_helper factory that already has add, update, delete reducers that can handle additional use-cases where just removing the child widget is not good enough. These reducers are similar enough to snabbdom modules, though in a sense much more limited.
• Maybe we should not pass the global widgets object to reducers because it may encourage sloppy coding
• We can make patching more efficient by formatting children to separate props from reducers so checking is faster.

Module approach (rewrite everything):

• Instead of current performPatch and destroyWidget functions, perhaps I can represent the data in the following form without any deep hierarchies so determining add, update, or delete is just a matter of running a diff.

  {
  '#container': { ...options },
  '#button': { ...options}
  }

• We can keep data structure as is but instead of performPatch calling the reducer stored inside the child, we call modules that perform the side effects instead.
• Children can set which modules they are compatible with, so a StackSidebar child does not run the default module that uses add instead of attach instead for example.
• The make_helper in this case will just pre-define which modules it is compatible with