Consider the following sentence — which I’ve italicized — from James S.A. Corey’s Leviathan Wakes: Earth’s imitation of a snail was picking up the pace as Earth- and Luna-based companies pulled back down the gravity well. I noticed that ‘based’ wasn’t needed/attached to the second Earth. Is that generally the rule or trend when stringing together similar compound modifiers?
I don't know that there's a rule, but that's probably the way I would have written that sentence. It wouldn't bother me to see it written with the extra 'based'.
Yeah, when the second word (like "based") is the same. Cf. "both high- and low-voltage" instead of "both high-voltage and low-voltage".
My question is whether the first en dash is needed. I'd probably exclude it, but it looks to be incorrect or nonstandard.
It's called a suspended hyphen. You just leave it floating after the first word like in the original line. There is a trick with it in some cases that I wasn't aware of. If you have a solid compound, a compound word that's connected without a hyphen, and you try the same trick there, a hyphen will appear where none was before. Chicago Manual gives this example as the trick case: both over- and underfed cats Which makes sense when I think about it. I probably wouldn't have done that on my own though, so I've learned something! It's a rare day when I do, haha. I need to study more.
