On Thu, 2020-05-21 at 11:46 -0400, Paul Smith wrote: > In my discussion of the way to handle conditions I even mentioned > allowing just one operand which would give the identity function. > > After sleeping on it, though, I'm not sure if that's the best idea. > Maybe we should assume "0" for a missing operand regardless of the > operator. > > That would mean $(op + 7 $(op < 10 5)) would be 7, but > $(op * 7 $(op < 10 5)) would be 0. That seems like it would be more > useful behavior than always choosing identity.
Or if this seems like too much magic, we could throw an error for a single operand and people could play a trick like this: $(op * 7 0$(op < 10 5)) (this means we cannot use leading 0 to mean octal form of course... I think that is going out of style anyway as too ambiguous). Or just write it all the way out: $(op * 7 $(if $(op < 10 5),1,0))
