One of the reasons that AssignPiece is so hairy is because it handles both splitting after the operator ("=", ":", etc.) and before "in".
Splitting out for-in loops to their own Piece class lets us get rid of a little of that complexity.
Also, I thought that was the only reason that the operator is a separate Piece. That's actually not true because we also need the LHS to be its own piece for applyConstraints().
Even so, I still think it's a little easier to understand with for-in loops being their own piece.
I also slightly tweaked the formatting of for-in loops. In the rare case where the left side block splits, we now indent it and split at "in". This is consistent with the old style. I don't have a strong preference, but I think it looks a little neater this way.
One of the reasons that AssignPiece is so hairy is because it handles both splitting after the operator ("=", ":", etc.) and before "in".
Splitting out for-in loops to their own Piece class lets us get rid of a little of that complexity.
Also, I thought that was the only reason that the operator is a separate Piece. That's actually not true because we also need the LHS to be its own piece for applyConstraints().
Even so, I still think it's a little easier to understand with for-in loops being their own piece.
I also slightly tweaked the formatting of for-in loops. In the rare case where the left side block splits, we now indent it and split at "in". This is consistent with the old style. I don't have a strong preference, but I think it looks a little neater this way.