Add "in-parens" and "in-brackets" to formatting attributes?

[Denis Maier]

Currently, we add parentheses and brackets via affixes. I'm contemplating whether we should adopt a quotes-like behavior? I.e, add attributes like "in-parens" and "in-brackets" to the formatting attributes. I imagine that could also make it easier for processors to implement some sort of context sensitive parentheses-to-brackets-and-back shifting mechanism.