3 files changed, 88 insertions, 1 deletions
diff --git a/haddock-library/haddock-library.cabal b/haddock-library/haddock-library.cabal
index 2e720d7b..44834aa9 100644
--- a/haddock-library/haddock-library.cabal
+++ b/haddock-library/haddock-library.cabal
@@ -31,10 +31,11 @@ library
   ghc-options:          -funbox-strict-fields -Wall -fwarn-tabs -O2
 
   exposed-modules:
+    Documentation.Haddock.Doc
+    Documentation.Haddock.Markup
     Documentation.Haddock.Parser
     Documentation.Haddock.Parser.Monad
     Documentation.Haddock.Types
-    Documentation.Haddock.Doc
     Documentation.Haddock.Utf8
 
   other-modules:
diff --git a/haddock-library/src/Documentation/Haddock/Markup.hs b/haddock-library/src/Documentation/Haddock/Markup.hs
new file mode 100644
index 00000000..b16cf049
--- /dev/null
+++ b/haddock-library/src/Documentation/Haddock/Markup.hs
@@ -0,0 +1,59 @@
+module Documentation.Haddock.Markup where
+
+import Documentation.Haddock.Types
+
+markup :: DocMarkupH mod id a -> DocH mod id -> a
+markup m DocEmpty                    = markupEmpty m
+markup m (DocAppend d1 d2)           = markupAppend m (markup m d1) (markup m d2)
+markup m (DocString s)               = markupString m s
+markup m (DocParagraph d)            = markupParagraph m (markup m d)
+markup m (DocIdentifier x)           = markupIdentifier m x
+markup m (DocIdentifierUnchecked x)  = markupIdentifierUnchecked m x
+markup m (DocModule mod0)            = markupModule m mod0
+markup m (DocWarning d)              = markupWarning m (markup m d)
+markup m (DocEmphasis d)             = markupEmphasis m (markup m d)
+markup m (DocBold d)                 = markupBold m (markup m d)
+markup m (DocMonospaced d)           = markupMonospaced m (markup m d)
+markup m (DocUnorderedList ds)       = markupUnorderedList m (map (markup m) ds)
+markup m (DocOrderedList ds)         = markupOrderedList m (map (markup m) ds)
+markup m (DocDefList ds)             = markupDefList m (map (markupPair m) ds)
+markup m (DocCodeBlock d)            = markupCodeBlock m (markup m d)
+markup m (DocHyperlink l)            = markupHyperlink m l
+markup m (DocAName ref)              = markupAName m ref
+markup m (DocPic img)                = markupPic m img
+markup m (DocMathInline mathjax)     = markupMathInline m mathjax
+markup m (DocMathDisplay mathjax)    = markupMathDisplay m mathjax
+markup m (DocProperty p)             = markupProperty m p
+markup m (DocExamples e)             = markupExample m e
+markup m (DocHeader (Header l t))    = markupHeader m (Header l (markup m t))
+
+markupPair :: DocMarkupH mod id a -> (DocH mod id, DocH mod id) -> (a, a)
+markupPair m (a,b) = (markup m a, markup m b)
+
+-- | The identity markup
+idMarkup :: DocMarkupH mod id (DocH mod id)
+idMarkup = Markup {
+  markupEmpty                = DocEmpty,
+  markupString               = DocString,
+  markupParagraph            = DocParagraph,
+  markupAppend               = DocAppend,
+  markupIdentifier           = DocIdentifier,
+  markupIdentifierUnchecked  = DocIdentifierUnchecked,
+  markupModule               = DocModule,
+  markupWarning              = DocWarning,
+  markupEmphasis             = DocEmphasis,
+  markupBold                 = DocBold,
+  markupMonospaced           = DocMonospaced,
+  markupUnorderedList        = DocUnorderedList,
+  markupOrderedList          = DocOrderedList,
+  markupDefList              = DocDefList,
+  markupCodeBlock            = DocCodeBlock,
+  markupHyperlink            = DocHyperlink,
+  markupAName                = DocAName,
+  markupPic                  = DocPic,
+  markupMathInline           = DocMathInline,
+  markupMathDisplay          = DocMathDisplay,
+  markupProperty             = DocProperty,
+  markupExample              = DocExamples,
+  markupHeader               = DocHeader
+  }
diff --git a/haddock-library/src/Documentation/Haddock/Types.hs b/haddock-library/src/Documentation/Haddock/Types.hs
index 660878ff..1e87edc0 100644
--- a/haddock-library/src/Documentation/Haddock/Types.hs
+++ b/haddock-library/src/Documentation/Haddock/Types.hs
@@ -80,3 +80,30 @@ data DocH mod id
   | DocExamples [Example]
   | DocHeader (Header (DocH mod id))
   deriving (Eq, Show, Functor, Foldable, Traversable)
+
+data DocMarkupH mod id a = Markup
+  { markupEmpty                :: a
+  , markupString               :: String -> a
+  , markupParagraph            :: a -> a
+  , markupAppend               :: a -> a -> a
+  , markupIdentifier           :: id -> a
+  , markupIdentifierUnchecked  :: mod -> a
+  , markupModule               :: String -> a
+  , markupWarning              :: a -> a
+  , markupEmphasis             :: a -> a
+  , markupBold                 :: a -> a
+  , markupMonospaced           :: a -> a
+  , markupUnorderedList        :: [a] -> a
+  , markupOrderedList          :: [a] -> a
+  , markupDefList              :: [(a,a)] -> a
+  , markupCodeBlock            :: a -> a
+  , markupHyperlink            :: Hyperlink -> a
+  , markupAName                :: String -> a
+  , markupPic                  :: Picture -> a
+  , markupMathInline           :: String -> a
+  , markupMathDisplay          :: String -> a
+  , markupProperty             :: String -> a
+  , markupExample              :: [Example] -> a
+  , markupHeader               :: Header a -> a
+  }
+