Does anyone use em dashes (or two hyphens) to denote speakers in dialogue passages? Joyce does this as does William Gaddis. Many others. I practice it, but my only "conceptual understanding" is that the dash-dialogue format allows you to group a character's entire range of actions, thoughts, and words into one chunk, headed by a dash. I really like this idea; it's very dramatic.
Here's an example which will lead to a more specific question.
Rick and Nelly walked through the cathedral.
-- It always makes me feel cold when I come here, he said shivering. I think it's something in the prayers.
One thing I seldom if ever have seen with dash-dialogue is the placement of the speaker tag at the end. So never this:
-- It always makes me feel cold when I come here, Rick said shivering.
So, I have made up a sort-of rule in my head that any speech tags or character blocking written into normal dialogue should only be inserted into the middle of dash-dialogue and not at the beginning or the end. My question is: does anyone know if there are specific rules to follow in writing this kind of dialogue?