Switch from pretty-simple to pretty-show for native output.

Update tests.

Reason:  it turns out that the native output generated by
pretty-simple isn't always readable by the native reader.
According to https://github.com/cdepillabout/pretty-simple/issues/99
it is not a design goal of the library that the rendered values
be readable using 'read'.  This makes it unsuitable for our
purposes.

pretty-show is a bit slower and it uses 4-space indents
(non-configurable), but it doesn't have this serious drawback.

6 files changed, 168 insertions, 158 deletions

diff --git a/test/fb2/reader/emphasis.native b/test/fb2/reader/emphasis.native
index 18fa49a8b..a3f4cdeb6 100644
--- a/test/fb2/reader/emphasis.native
+++ b/test/fb2/reader/emphasis.native
@@ -1,38 +1,35 @@
 Pandoc
-  ( Meta { unMeta = fromList [] } )
+  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 "."
+      ( "" , [ "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" ]
       ]
-    , 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 2eaa6da41..eb11c1d79 100644
--- a/test/fb2/reader/epigraph.native
+++ b/test/fb2/reader/epigraph.native
@@ -1,18 +1,18 @@
 Pandoc
-  ( Meta { unMeta = fromList [] } )
+  Meta { unMeta = fromList [] }
   [ Div
-    ( "", [ "epigraph" ], [] )
-    [ Para [ Str "Body", Space, Str "epigraph" ] ]
+      ( "" , [ "epigraph" ] , [] )
+      [ Para [ Str "Body" , Space , Str "epigraph" ] ]
   , Div
-    ( "", [ "section" ], [] )
-    [ Div
-      ( "", [ "epigraph" ], [] )
-      [ Para [ Str "Section", Space, Str "epigraph" ] ]
-    , Div
-      ( "", [ "section" ], [] )
+      ( "" , [ "section" ] , [] )
       [ Div
-        ( "", [ "epigraph" ], [] )
-        [ Para [ Str "Subsection", Space, Str "epigraph" ] ]
+          ( "" , [ "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 37d229755..851250296 100644
--- a/test/fb2/reader/meta.native
+++ b/test/fb2/reader/meta.native
@@ -1,43 +1,48 @@
 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"
-            ]
+  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" ]
+            )
           ]
-        )
-      ,
-        ( "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" ] ]
+  [ Header
+      1 ( "" , [] , [] ) [ Str "Body" , Space , Str "title" ]
+  ]
diff --git a/test/fb2/reader/notes.native b/test/fb2/reader/notes.native
index 6ff16e701..56fa3873f 100644
--- a/test/fb2/reader/notes.native
+++ b/test/fb2/reader/notes.native
@@ -1,24 +1,28 @@
 Pandoc
-  ( Meta { unMeta = fromList [] } )
+  Meta { unMeta = fromList [] }
   [ Div
-    ( "", [ "section" ], [] )
-    [ Para
-      [ Str "Note"
-      , Space
-      , Note
-        [ Para [ Str "Note", Space, Str "contents" ] ]
-      , Str "."
+      ( "" , [ "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 "."
+          ]
       ]
-    , 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 a43466b16..2b45347e8 100644
--- a/test/fb2/reader/poem.native
+++ b/test/fb2/reader/poem.native
@@ -1,26 +1,25 @@
 Pandoc
-  ( Meta { unMeta = fromList [] } )
+  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" ]
-    ]
+      ( "" , [ "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 f98d0b00c..74669d848 100644
--- a/test/fb2/reader/titles.native
+++ b/test/fb2/reader/titles.native
@@ -1,33 +1,38 @@
 Pandoc
-  ( Meta { unMeta = fromList [] } )
-  [ Header 1
-    ( "", [], [] )
-    [ Str "Body", Space, Str "title" ]
+  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"
-        ]
+      ( "" , [ "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"
+              ]
+          ]
       ]
-    , Div
-      ( "", [ "section" ], [] )
-      [ Header 3
-        ( "", [], [] )
-        [ Str "Another", Space, Str "subsection", Space, Str "title" ]
-      ]
-    ]
   ]