Proposal: Add Text.PrettyPrint.HughesPJ.zeroText

[Neil Mitchell]

Hi

> > I would have thought the term zeroText more accurately signifies the
> > meaning, partly because out-of-band isn't such a commonly known
> > phrase. If anyone can suggest anything better than zeroText, then I'm
> > happy to hear it.
>
> I don't know if I prefer one over the other, but in my attached
> implementation of Wadler's pretty printer (basically stolen directly
> from the paper), I'd called this control.

I don't like control because of Control.Monad

Cale on IRC suggested invisible, so far thats the best name I think.

Thanks

Neil