Is it possible in Heirloom troff to invoke a macro from a string? There is an escape sequence: \R'R ±N' => Set number register R to ±N
This is useful, but the expression is too limiting in some cases. For example, is it possible to increase register R by 1 only if it hasn't reached a maximum value? There is also an output line trap escape sequence: \Px,\P(xx,\P[xxx] => Output-line trap x, xx, or xxx This is very useful (and very close), but there are situations where one would need for that macro to be invoked at that *exact* location, as opposed to later, when the text is printed. Thank you!
