write a FilePickerCtrl component

[jamesdbrock]

I want to write a FilePickerCtrl component. Any advice?

It seems like writing new primitive components is a bit awkward because the re.widgets.set_basic_props function has no way to amend the exclusions map. So I have to either fork re-wx or make a new set_basic_props function. Do I have that right?

[jamesdbrock]

Ah, actually, the only way to add new primitive components is to fork the re-wx repo, right? Because core.py gets the mount and update decorator registries from widgets.py.

[jamesdbrock]

I take it back, the @mount.register and @update.register decorators work anywhere in user code.

[jamesdbrock]

I'm pretty sure this is essentially an implementation of Haskell or PureScript “typeclasses” in Python.

re-wx/rewx/dispatch.py

Lines 4 to 8 in 882967e

	def dispatch(func):
	"""
	Constructs a registry for performing single dispatch based on
	the class (not instance) type
	"""

[chriskiehl]

I take it back, the @mount.register and @update.register decorators work anywhere in user code.

Yeah, correct. You can see a few examples of it in use in Gooey.

I'm pretty sure this is essentially an implementation of Haskell or PureScript “typeclasses” in Python.

Oh, interesting. I hadn't thought of it that way. The motivation here was primarily multi-methods from Clojure. They're definitely clumsier than typeclasses because of how Python treats its objects. There's actually a builtin version of this dispatch thing in functools called @singledispatch. However, it only works correctly for instances of types, which have the Type you'd expect (int, string, MyObject, etc..) whereas the type of a class, is type (which I think is sort of like Kind in Purecsript).

class Foo:
    pass  

print(type(Foo())  # <class '__main__.Foo'>
print(type(Foo))   # <class 'type'>

This quirk breaks the builtin singledispatch because everything bottoms out on Type.