question: scheme-like identifiers

[nikomatsakis]

I've been using scheme lately and I have to say that being able to create identifiers that include all kinds of characters is...super fun and liberating? Like unify/vars or my:unification+engine or even just this-is-a-name. Combined with the fact that forcing spaces around binary operators would solve a few parsing problems, I am wondering about allowing variables to include "infix" or "postfix" punctuation. Obviously some characters (:, =, (, ), [, ], maybe a few others) would still be reserved.

I think I would still reserve punctuation at the beginning of an identifier, too, to allow for -x as the equivalent of 0 - x.