Continuing the discussion from Macro Keyword:
If we allowed macros that take exactly 1 token to be called as
macro! token then we would effectively have custom literals. This could be as simple as
s!"custom String literals" or as complex as other programming languages as literals. A token being something matched by the
tt macro specifier, but excluding grouping tokens for back-conpat.
This is a rather small change, but it opens the door to some very interesting and useful idioms. (For example,