- (Nothing, Just (r,i)) -> pp_off (hcat [pp_reg r, comma, int i])
- (Just b, Just (r,i)) -> pp_off (hcat [pp_reg b, comma, pp_reg r, comma, int i])
+ (Nothing, Just (r,i)) -> pp_off (pp_reg r <> comma <> int i)
+ (Just b, Just (r,i)) -> pp_off (pp_reg b <> comma <> pp_reg r
+ <> comma <> int i)