ppr_offset :: Int -> SDoc
ppr_offset i
    | i==0      = empty
    | i>=0      = char '+' <> int i
    | otherwise = char '-' <> int (-i)
ppr_offset :: Int -> SDoc
ppr_offset i
    | i==0      = empty
    | i>=0      = char '+' <> int i
    | otherwise = char '-' <> int (-i)
ppr_offset i
    | i==0      = empty
    | i>=0      = char '+' <> int i
    | otherwise = char '-' <> int (-i)