{- |
Module: Pollock.Documentation.MetadataAndDoc
Copyright: (c) Trevis Elser 2023
License: MIT
Maintainer: trevis@flipstone.com
Stability: experimental
-}
module Pollock.Documentation.MetadataAndDoc
  ( MetaAndDoc (..)
  , withEmptyMetadata
  , metaAndDocConcat
  , metaAndDocAppend
  ) where

import Pollock.Documentation.Doc (Doc (DocEmpty), docAppend)
import Pollock.Documentation.Metadata
  ( Metadata
  , emptyMetadata
  , metaAppend
  )

data MetaAndDoc = MetaAndDoc
  { meta :: !Metadata
  , doc :: !Doc
  }

withEmptyMetadata :: Doc -> MetaAndDoc
withEmptyMetadata d =
  MetaAndDoc
    { meta = emptyMetadata
    , doc = d
    }

metaAndDocConcat :: [MetaAndDoc] -> MetaAndDoc
metaAndDocConcat = foldr metaAndDocAppend emptyMetaAndDoc

-- Append where for metadata prefence is on the right, but for doc it is on the left.
metaAndDocAppend :: MetaAndDoc -> MetaAndDoc -> MetaAndDoc
metaAndDocAppend md1 md2 =
  MetaAndDoc
    { meta = metaAppend (meta md2) (meta md1)
    , doc = docAppend (doc md1) (doc md2)
    }

emptyMetaAndDoc :: MetaAndDoc
emptyMetaAndDoc = MetaAndDoc{meta = emptyMetadata, doc = DocEmpty}