-- | Optionally combine the second argument with the first,
--   or return it unchanged if the first argument is 'Nothing'.
(<?+>) :: Maybe SrcSpanInfo -> SrcSpanInfo -> SrcSpanInfo
a <?+> b = case a of {Nothing -> b; Just a -> a <++> b}
(<?+>) :: Maybe SrcSpanInfo -> SrcSpanInfo -> SrcSpanInfo
a <?+> b = case a of {Nothing -> b; Just a -> a <++> b}
a <?+> b = case a of {Nothing -> b; Just a -> a <++> b}