Use pretty-simple to format native output.

Previously we used our own homespun formatting.  But this
produces over-long lines that aren't ideal for diffs in tests.
Easier to use something off-the-shelf and standard.

Closes #7580.

Performance is slower by about a factor of 10, but this isn't
really a problem because native isn't suitable as a serialization
format. (For serialization you should use json, because the reader
is so much faster than native.)

6 files changed, 182 insertions, 43 deletions

diff --git a/test/fb2/reader/emphasis.native b/test/fb2/reader/emphasis.native
index 422e7bb15..18fa49a8b 100644
--- a/test/fb2/reader/emphasis.native
+++ b/test/fb2/reader/emphasis.native
@@ -1,6 +1,38 @@
-Pandoc (Meta {unMeta = fromList []})
-[Div ("",["section"],[])
- [Para [Str "Plain,",Space,Strong [Str "strong"],Str ",",Space,Emph [Str "emphasis"],Str ",",Space,Strong [Emph [Str "strong",Space,Str "emphasis"]],Str ",",Space,Emph [Strong [Str "emphasized",Space,Str "strong"]],Str "."]
- ,Para [Str "Strikethrough:",Space,Strikeout [Str "deleted"]]
- ,Para [Subscript [Str "Subscript"],Space,Str "and",Space,Superscript [Str "superscript"]]
- ,Para [Str "Some",Space,Code ("",[],[]) "code"]]]
+Pandoc
+  ( Meta { unMeta = fromList [] } )
+  [ Div
+    ( "", [ "section" ], [] )
+    [ Para
+      [ Str "Plain,"
+      , Space
+      , Strong
+        [ Str "strong" ]
+      , Str ","
+      , Space
+      , Emph
+        [ Str "emphasis" ]
+      , Str ","
+      , Space
+      , Strong
+        [ Emph [ Str "strong", Space, Str "emphasis" ] ]
+      , Str ","
+      , Space
+      , Emph
+        [ Strong [ Str "emphasized", Space, Str "strong" ] ]
+      , Str "."
+      ]
+    , Para
+      [ Str "Strikethrough:", Space, Strikeout [ Str "deleted" ] ]
+    , Para
+      [ Subscript
+        [ Str "Subscript" ]
+      , Space
+      , Str "and"
+      , Space
+      , Superscript
+        [ Str "superscript" ]
+      ]
+    , Para
+      [ Str "Some", Space, Code ( "", [], [] ) "code" ]
+    ]
+  ]
diff --git a/test/fb2/reader/epigraph.native b/test/fb2/reader/epigraph.native
index a58a3e05b..2eaa6da41 100644
--- a/test/fb2/reader/epigraph.native
+++ b/test/fb2/reader/epigraph.native
@@ -1,9 +1,18 @@
-Pandoc (Meta {unMeta = fromList []})
-[Div ("",["epigraph"],[])
- [Para [Str "Body",Space,Str "epigraph"]]
-,Div ("",["section"],[])
- [Div ("",["epigraph"],[])
-  [Para [Str "Section",Space,Str "epigraph"]]
- ,Div ("",["section"],[])
-  [Div ("",["epigraph"],[])
-   [Para [Str "Subsection",Space,Str "epigraph"]]]]]
+Pandoc
+  ( Meta { unMeta = fromList [] } )
+  [ Div
+    ( "", [ "epigraph" ], [] )
+    [ Para [ Str "Body", Space, Str "epigraph" ] ]
+  , Div
+    ( "", [ "section" ], [] )
+    [ Div
+      ( "", [ "epigraph" ], [] )
+      [ Para [ Str "Section", Space, Str "epigraph" ] ]
+    , Div
+      ( "", [ "section" ], [] )
+      [ Div
+        ( "", [ "epigraph" ], [] )
+        [ Para [ Str "Subsection", Space, Str "epigraph" ] ]
+      ]
+    ]
+  ]
diff --git a/test/fb2/reader/meta.native b/test/fb2/reader/meta.native
index 71a8795b6..37d229755 100644
--- a/test/fb2/reader/meta.native
+++ b/test/fb2/reader/meta.native
@@ -1,2 +1,43 @@
-Pandoc (Meta {unMeta = fromList [("abstract",MetaBlocks [Para [Str "Book",Space,Str "annotation"],Para [Str "Second",Space,Str "paragraph",Space,Str "of",Space,Str "book",Space,Str "annotation"]]),("author",MetaList [MetaInlines [Str "First",Space,Str "Middle",Space,Str "Last"],MetaInlines [Str "Another",Space,Str "Author"]]),("date",MetaInlines [Str "2018"]),("keywords",MetaList [MetaString "foo",MetaString "bar",MetaString "baz"]),("title",MetaInlines [Str "Book",Space,Str "title"])]})
-[Header 1 ("",[],[]) [Str "Body",Space,Str "title"]]
+Pandoc
+  ( Meta
+    { unMeta = fromList
+      [
+        ( "abstract"
+        , MetaBlocks
+          [ Para
+            [ Str "Book", Space, Str "annotation" ]
+          , Para
+            [ Str "Second"
+            , Space
+            , Str "paragraph"
+            , Space
+            , Str "of"
+            , Space
+            , Str "book"
+            , Space
+            , Str "annotation"
+            ]
+          ]
+        )
+      ,
+        ( "author"
+        , MetaList
+          [ MetaInlines
+            [ Str "First", Space, Str "Middle", Space, Str "Last" ]
+          , MetaInlines
+            [ Str "Another", Space, Str "Author" ]
+          ]
+        )
+      ,
+        ( "date", MetaInlines [ Str "2018" ] )
+      ,
+        ( "keywords"
+        , MetaList
+          [ MetaString "foo", MetaString "bar", MetaString "baz" ]
+        )
+      ,
+        ( "title", MetaInlines [ Str "Book", Space, Str "title" ] )
+      ]
+    }
+  )
+  [ Header 1 ( "", [], [] ) [ Str "Body", Space, Str "title" ] ]
diff --git a/test/fb2/reader/notes.native b/test/fb2/reader/notes.native
index f229209cd..6ff16e701 100644
--- a/test/fb2/reader/notes.native
+++ b/test/fb2/reader/notes.native
@@ -1,4 +1,24 @@
-Pandoc (Meta {unMeta = fromList []})
-[Div ("",["section"],[])
- [Para [Str "Note",Space,Note [Para [Str "Note",Space,Str "contents"]],Str "."]
- ,Para [Str "Second",Space,Str "note",Space,Note [Para [Str "Second",Space,Str "note",Space,Str "contents."]],Str "."]]]
+Pandoc
+  ( Meta { unMeta = fromList [] } )
+  [ Div
+    ( "", [ "section" ], [] )
+    [ Para
+      [ Str "Note"
+      , Space
+      , Note
+        [ Para [ Str "Note", Space, Str "contents" ] ]
+      , Str "."
+      ]
+    , Para
+      [ Str "Second"
+      , Space
+      , Str "note"
+      , Space
+      , Note
+        [ Para
+          [ Str "Second", Space, Str "note", Space, Str "contents." ]
+        ]
+      , Str "."
+      ]
+    ]
+  ]
diff --git a/test/fb2/reader/poem.native b/test/fb2/reader/poem.native
index 67be6a672..a43466b16 100644
--- a/test/fb2/reader/poem.native
+++ b/test/fb2/reader/poem.native
@@ -1,14 +1,26 @@
-Pandoc (Meta {unMeta = fromList []})
-[Div ("",["section"],[])
- [Header 2 ("",[],[]) [Str "Poem",Space,Str "title"]
- ,Div ("",["epigraph"],[])
-  [Para [Str "Poem",Space,Str "epigraph"]]
- ,Header 2 ("",["unnumbered"],[]) [Str "Subtitle"]
- ,Header 2 ("",[],[]) [Str "First",Space,Str "stanza",Space,Str "title"]
- ,LineBlock
-  [[Str "Verse"]
-  ,[Emph [Str "More"],Space,Str "verse"]]
- ,LineBlock
-  [[Str "One",Space,Str "more",Space,Str "stanza"]]
- ,Para [Str "Author"]
- ,Para [Str "April",Space,Str "2018"]]]
+Pandoc
+  ( Meta { unMeta = fromList [] } )
+  [ Div
+    ( "", [ "section" ], [] )
+    [ Header 2
+      ( "", [], [] )
+      [ Str "Poem", Space, Str "title" ]
+    , Div
+      ( "", [ "epigraph" ], [] )
+      [ Para [ Str "Poem", Space, Str "epigraph" ] ]
+    , Header 2
+      ( "", [ "unnumbered" ], [] )
+      [ Str "Subtitle" ]
+    , Header 2
+      ( "", [], [] )
+      [ Str "First", Space, Str "stanza", Space, Str "title" ]
+    , LineBlock
+      [ [ Str "Verse" ], [ Emph [ Str "More" ], Space, Str "verse" ] ]
+    , LineBlock
+      [ [ Str "One", Space, Str "more", Space, Str "stanza" ] ]
+    , Para
+      [ Str "Author" ]
+    , Para
+      [ Str "April", Space, Str "2018" ]
+    ]
+  ]
diff --git a/test/fb2/reader/titles.native b/test/fb2/reader/titles.native
index a6c34f5ea..f98d0b00c 100644
--- a/test/fb2/reader/titles.native
+++ b/test/fb2/reader/titles.native
@@ -1,8 +1,33 @@
-Pandoc (Meta {unMeta = fromList []})
-[Header 1 ("",[],[]) [Str "Body",Space,Str "title"]
-,Div ("",["section"],[])
- [Header 2 ("",[],[]) [Str "Section",Space,Str "title"]
- ,Div ("",["section"],[])
-  [Header 3 ("",[],[]) [Str "Subsection",Space,Str "title",LineBreak,Str "with",Space,Str "multiple",Space,Str "paragraphs"]]
- ,Div ("",["section"],[])
-  [Header 3 ("",[],[]) [Str "Another",Space,Str "subsection",Space,Str "title"]]]]
+Pandoc
+  ( Meta { unMeta = fromList [] } )
+  [ Header 1
+    ( "", [], [] )
+    [ Str "Body", Space, Str "title" ]
+  , Div
+    ( "", [ "section" ], [] )
+    [ Header 2
+      ( "", [], [] )
+      [ Str "Section", Space, Str "title" ]
+    , Div
+      ( "", [ "section" ], [] )
+      [ Header 3
+        ( "", [], [] )
+        [ Str "Subsection"
+        , Space
+        , Str "title"
+        , LineBreak
+        , Str "with"
+        , Space
+        , Str "multiple"
+        , Space
+        , Str "paragraphs"
+        ]
+      ]
+    , Div
+      ( "", [ "section" ], [] )
+      [ Header 3
+        ( "", [], [] )
+        [ Str "Another", Space, Str "subsection", Space, Str "title" ]
+      ]
+    ]
+  ]