On Sun, 28 Jan 2024 19:36:29 +0000 Donald Hunter wrote:
> > from collections import ChainMap
> >
> > class LevelChainMap(ChainMap):
> > def __getitem__(self, key):
> > for mapping in self.maps:
> > try:
> > return mapping[key], self.maps[::-1].index(mapping)
> > except KeyError:
> > pass
> > return self.__missing__(key)
> >
> > def get(self, key, default=None, level=None):
> > val, lvl = self[key] if key in self else (default, None)
> > if level:
> > if lvl != level:
> > raise Exception("Level mismatch")
> > return val, lvl
> >
> > # example usage
> > c = LevelChainMap({'a':1}, {'inner':{'a':1}}, {'outer': {'inner':{'a':1}}})
> > print(c.get('a', level=2))
> > print(c.get('a', level=1)) #raise err
> >
> > This will leave the spec as it is and will require small changes.
> >
> > What do you think?
>
> The more I think about it, the more I agree that using path-like syntax
> in the selector is overkill. It makes sense to resolve the selector
> level from the spec and then directly access the mappings from the
> correct scope level.
Plus if we resolve from the spec that's easily reusable in C / C++
code gen :)
