smart: spacing around dashes

[avidseeker]

smart extension translates -- and --- to en and em dashes. E.g:

Lorem ipsum ---sed do--- eiusmod -- tempor -- incididunt.
↓
Lorem ipsum —sed do— eiusmod – tempor – incididunt.

However, there seems to be different conventions around the spacing of dashes.

• AP Style: Insert a space before and after the em dash, except when used to introduce items in a vertical list.
• Chicago Manual of Style: No spaces around the em dash.
• Newspapers and some magazines: Typically insert a space before and after the em dash.
• Books and journals: Often omit spacing, closing the surrounding text right up next to the em dash.

Can pandoc take an extra layer of abstraction to specify whether to include a space in the output or not?

[jgm]

I'd prefer not to complicate things too much by introducing extra options. It's easy enough to use a Lua filter to add space around all the Em dashes (you'd want nonbreaking spaces in any case, and maybe just partial spaces -- anyway, everyone will want something slightly different).

There's a discussion #10013 about configuring smart quotes. If we added a way to do that, we could in principle extend it to dashes and ellipses. But at the moment it's a low priority issue.