Merge pull request #1317 from bgamari/wip/ghc-head-merge

Merge ghc-8.10 into ghc-head

22 files changed, 498 insertions, 207 deletions

diff --git a/haddock-library/.ghci b/haddock-library/.ghci
deleted file mode 100644
index 78950a5b..00000000
--- a/haddock-library/.ghci
+++ /dev/null
@@ -1 +0,0 @@
-:set -isrc -ivendor/attoparsec-0.12.1.1 -itest -idist/build -idist/build/autogen -optP-include -optPdist/build/autogen/cabal_macros.h
diff --git a/haddock-library/CHANGES.md b/haddock-library/CHANGES.md
index 265579ca..5b400d7c 100644
--- a/haddock-library/CHANGES.md
+++ b/haddock-library/CHANGES.md
@@ -1,3 +1,9 @@
+## Changes in version 1.9.0
+
+ * Fix build-time regression for `base < 4.7` (#1119)
+
+ * Update parsing to strip whitespace from table cells (#1074)
+
 ## Changes in version 1.8.0
 
  * Support inline markup in markdown-style links (#875)
diff --git a/haddock-library/fixtures/examples/list-blocks1.input b/haddock-library/fixtures/examples/list-blocks1.input
new file mode 100644
index 00000000..72a0640b
--- /dev/null
+++ b/haddock-library/fixtures/examples/list-blocks1.input
@@ -0,0 +1,15 @@
+* Something about foo
+
+    @
+    foo :: a -> b -> c
+    foo a b = bar c b
+    @
+
+* Something about bar
+
+    @
+    bar :: a -> b -> c
+    bar a b = foo b a
+    @
+
+* And then we continue
diff --git a/haddock-library/fixtures/examples/list-blocks1.parsed b/haddock-library/fixtures/examples/list-blocks1.parsed
new file mode 100644
index 00000000..9fc4f0ba
--- /dev/null
+++ b/haddock-library/fixtures/examples/list-blocks1.parsed
@@ -0,0 +1,12 @@
+DocUnorderedList
+  [DocAppend
+     (DocParagraph (DocString "Something about foo"))
+     (DocCodeBlock
+        (DocString
+           (concat ["foo :: a -> b -> c\n", "foo a b = bar c b\n"]))),
+   DocAppend
+     (DocParagraph (DocString "Something about bar"))
+     (DocCodeBlock
+        (DocString
+           (concat ["bar :: a -> b -> c\n", "bar a b = foo b a\n"]))),
+   DocParagraph (DocString "And then we continue")]
diff --git a/haddock-library/fixtures/examples/list-blocks2.input b/haddock-library/fixtures/examples/list-blocks2.input
new file mode 100644
index 00000000..91492adb
--- /dev/null
+++ b/haddock-library/fixtures/examples/list-blocks2.input
@@ -0,0 +1,10 @@
+=== Title
+
+* List directly
+* after the title
+
+    @
+    with some inline things
+    @
+
+* is parsed weirdly
diff --git a/haddock-library/fixtures/examples/list-blocks2.parsed b/haddock-library/fixtures/examples/list-blocks2.parsed
new file mode 100644
index 00000000..169677b7
--- /dev/null
+++ b/haddock-library/fixtures/examples/list-blocks2.parsed
@@ -0,0 +1,10 @@
+DocAppend
+  (DocAppend
+     (DocHeader
+        Header {headerLevel = 3, headerTitle = DocString "Title"})
+     (DocUnorderedList
+        [DocParagraph (DocString "List directly"),
+         DocAppend
+           (DocParagraph (DocString "after the title"))
+           (DocCodeBlock (DocString "with some inline things\n"))]))
+  (DocUnorderedList [DocParagraph (DocString "is parsed weirdly")])
diff --git a/haddock-library/fixtures/examples/table-cell-strip-whitespaces.input b/haddock-library/fixtures/examples/table-cell-strip-whitespaces.input
new file mode 100644
index 00000000..f5e3756d
--- /dev/null
+++ b/haddock-library/fixtures/examples/table-cell-strip-whitespaces.input
@@ -0,0 +1,5 @@
++------+--------------+-------------------------------------------------+
+| C1   |     C2       |         C3                                      |
++======+==============+=================================================+
+| row  | 'test'       | 'test table cell with  .. whitepspace '         |
++------+--------------+-------------------------------------------------+
diff --git a/haddock-library/fixtures/examples/table-cell-strip-whitespaces.parsed b/haddock-library/fixtures/examples/table-cell-strip-whitespaces.parsed
new file mode 100644
index 00000000..19002369
--- /dev/null
+++ b/haddock-library/fixtures/examples/table-cell-strip-whitespaces.parsed
@@ -0,0 +1,29 @@
+DocTable
+  Table
+    {tableBodyRows = [TableRow
+                        [TableCell
+                           {tableCellColspan = 1,
+                            tableCellContents = DocString "row",
+                            tableCellRowspan = 1},
+                         TableCell
+                           {tableCellColspan = 1,
+                            tableCellContents = DocIdentifier "test",
+                            tableCellRowspan = 1},
+                         TableCell
+                           {tableCellColspan = 1,
+                            tableCellContents = DocString
+                                                  "'test table cell with  .. whitepspace '",
+                            tableCellRowspan = 1}]],
+     tableHeaderRows = [TableRow
+                          [TableCell
+                             {tableCellColspan = 1,
+                              tableCellContents = DocString "C1",
+                              tableCellRowspan = 1},
+                           TableCell
+                             {tableCellColspan = 1,
+                              tableCellContents = DocString "C2",
+                              tableCellRowspan = 1},
+                           TableCell
+                             {tableCellColspan = 1,
+                              tableCellContents = DocString "C3",
+                              tableCellRowspan = 1}]]}
diff --git a/haddock-library/fixtures/examples/table-simple.parsed b/haddock-library/fixtures/examples/table-simple.parsed
index b5e62453..d027c75d 100644
--- a/haddock-library/fixtures/examples/table-simple.parsed
+++ b/haddock-library/fixtures/examples/table-simple.parsed
@@ -3,50 +3,40 @@ DocTable
     {tableBodyRows = [TableRow
                         [TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString " 200  ",
+                            tableCellContents = DocString "200",
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocAppend
-                                                  (DocString "   ")
-                                                  (DocAppend
-                                                     (DocMonospaced (DocString "OK"))
-                                                     (DocString "       ")),
+                            tableCellContents = DocMonospaced (DocString "OK"),
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString
-                                                  " operation successful                     ",
+                            tableCellContents = DocString "operation successful",
                             tableCellRowspan = 1}],
                       TableRow
                         [TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString " 204  ",
+                            tableCellContents = DocString "204",
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocAppend
-                                                  (DocString " ")
-                                                  (DocAppend
-                                                     (DocMonospaced (DocString "No Content"))
-                                                     (DocString " ")),
+                            tableCellContents = DocMonospaced (DocString "No Content"),
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 1,
                             tableCellContents = DocString
-                                                  " operation successful, no body returned   ",
+                                                  "operation successful, no body returned",
                             tableCellRowspan = 1}]],
      tableHeaderRows = [TableRow
                           [TableCell
                              {tableCellColspan = 1,
-                              tableCellContents = DocString " code ",
+                              tableCellContents = DocString "code",
                               tableCellRowspan = 1},
                            TableCell
                              {tableCellColspan = 1,
-                              tableCellContents = DocString " message      ",
+                              tableCellContents = DocString "message",
                               tableCellRowspan = 1},
                            TableCell
                              {tableCellColspan = 1,
-                              tableCellContents = DocString
-                                                    " description                              ",
+                              tableCellContents = DocString "description",
                               tableCellRowspan = 1}]]}
diff --git a/haddock-library/fixtures/examples/table1.parsed b/haddock-library/fixtures/examples/table1.parsed
index 2fa58fd8..8b8908f4 100644
--- a/haddock-library/fixtures/examples/table1.parsed
+++ b/haddock-library/fixtures/examples/table1.parsed
@@ -3,79 +3,66 @@ DocTable
     {tableBodyRows = [TableRow
                         [TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString " body row 1, column 1   ",
+                            tableCellContents = DocString "body row 1, column 1",
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString " column 2   ",
+                            tableCellContents = DocString "column 2",
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString " column 3 ",
+                            tableCellContents = DocString "column 3",
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString " column 4 ",
+                            tableCellContents = DocString "column 4",
                             tableCellRowspan = 1}],
                       TableRow
                         [TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString " body row 2             ",
+                            tableCellContents = DocString "body row 2",
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 3,
-                            tableCellContents = DocString " Cells may span columns.          ",
+                            tableCellContents = DocString "Cells may span columns.",
                             tableCellRowspan = 1}],
                       TableRow
                         [TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString " body row 3             ",
+                            tableCellContents = DocString "body row 3",
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 1,
                             tableCellContents = DocString
-                                                  (concat
-                                                     [" Cells may  \n",
-                                                      " span rows. \n",
-                                                      "            "]),
+                                                  (concat ["Cells may\n", "span rows.\n"]),
                             tableCellRowspan = 2},
                          TableCell
                            {tableCellColspan = 2,
-                            tableCellContents = DocAppend
-                                                  (DocString " ")
-                                                  (DocAppend
-                                                     (DocMathDisplay
-                                                        (concat
-                                                           ["                  \n",
-                                                            " f(n) = \\sum_{i=1}   \n",
-                                                            " "]))
-                                                     (DocString "                  ")),
+                            tableCellContents = DocMathDisplay
+                                                  (concat ["\n", "f(n) = \\sum_{i=1}\n"]),
                             tableCellRowspan = 2}],
                       TableRow
                         [TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString " body row 4             ",
+                            tableCellContents = DocString "body row 4",
                             tableCellRowspan = 1}]],
      tableHeaderRows = [TableRow
                           [TableCell
                              {tableCellColspan = 1,
                               tableCellContents = DocString
                                                     (concat
-                                                       [" Header row, column 1   \n",
-                                                        " (header rows optional) "]),
+                                                       ["Header row, column 1\n",
+                                                        "(header rows optional)"]),
                               tableCellRowspan = 1},
                            TableCell
                              {tableCellColspan = 1,
-                              tableCellContents = DocString
-                                                    (concat [" Header 2   \n", "            "]),
+                              tableCellContents = DocString "Header 2\n",
                               tableCellRowspan = 1},
                            TableCell
                              {tableCellColspan = 1,
-                              tableCellContents = DocString
-                                                    (concat [" Header 3 \n", "          "]),
+                              tableCellContents = DocString "Header 3\n",
                               tableCellRowspan = 1},
                            TableCell
                              {tableCellColspan = 1,
-                              tableCellContents = DocString
-                                                    (concat [" Header 4 \n", "          "]),
+                              tableCellContents = DocString "Header 4\n",
                               tableCellRowspan = 1}]]}
diff --git a/haddock-library/fixtures/examples/table2.parsed b/haddock-library/fixtures/examples/table2.parsed
index e3dbf0b4..44cc813b 100644
--- a/haddock-library/fixtures/examples/table2.parsed
+++ b/haddock-library/fixtures/examples/table2.parsed
@@ -3,44 +3,44 @@ DocTable
     {tableBodyRows = [TableRow
                         [TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString " row 1, col 1 ",
+                            tableCellContents = DocString "row 1, col 1",
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString " column 2 ",
+                            tableCellContents = DocString "column 2",
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString " column 3  ",
+                            tableCellContents = DocString "column 3",
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString " column 4  ",
+                            tableCellContents = DocString "column 4",
                             tableCellRowspan = 1}],
                       TableRow
                         [TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString " row 2        ",
+                            tableCellContents = DocString "row 2",
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 3,
-                            tableCellContents = DocString "                                  ",
+                            tableCellContents = DocEmpty,
                             tableCellRowspan = 1}],
                       TableRow
                         [TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString " row 3        ",
+                            tableCellContents = DocString "row 3",
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString "          ",
+                            tableCellContents = DocEmpty,
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString "           ",
+                            tableCellContents = DocEmpty,
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString "           ",
+                            tableCellContents = DocEmpty,
                             tableCellRowspan = 1}]],
      tableHeaderRows = []}
diff --git a/haddock-library/fixtures/examples/table3.parsed b/haddock-library/fixtures/examples/table3.parsed
index cabff9cb..c978b50f 100644
--- a/haddock-library/fixtures/examples/table3.parsed
+++ b/haddock-library/fixtures/examples/table3.parsed
@@ -3,48 +3,48 @@ DocTable
     {tableBodyRows = [TableRow
                         [TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString " row 1, col 1 ",
+                            tableCellContents = DocString "row 1, col 1",
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString " column 2 ",
+                            tableCellContents = DocString "column 2",
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString " column 3  ",
+                            tableCellContents = DocString "column 3",
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString " column 4  ",
+                            tableCellContents = DocString "column 4",
                             tableCellRowspan = 1}],
                       TableRow
                         [TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString " row 2        ",
+                            tableCellContents = DocString "row 2",
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 2,
-                            tableCellContents = DocString " Use the command ``ls ",
+                            tableCellContents = DocString "Use the command ``ls",
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString " more``.   ",
+                            tableCellContents = DocString "more``.",
                             tableCellRowspan = 1}],
                       TableRow
                         [TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString " row 3        ",
+                            tableCellContents = DocString "row 3",
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString "          ",
+                            tableCellContents = DocEmpty,
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString "           ",
+                            tableCellContents = DocEmpty,
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString "           ",
+                            tableCellContents = DocEmpty,
                             tableCellRowspan = 1}]],
      tableHeaderRows = []}
diff --git a/haddock-library/fixtures/examples/table4.parsed b/haddock-library/fixtures/examples/table4.parsed
index cfdd6f0f..c4dabb0d 100644
--- a/haddock-library/fixtures/examples/table4.parsed
+++ b/haddock-library/fixtures/examples/table4.parsed
@@ -8,10 +8,10 @@ DocAppend
                                  {tableCellColspan = 1,
                                   tableCellContents = DocString
                                                         (concat
-                                                           ["   outer     \n",
-                                                            "             \n",
-                                                            "-------+     \n",
-                                                            " inner |     "]),
+                                                           ["outer\n",
+                                                            "\n",
+                                                            "-------+\n",
+                                                            "inner |"]),
                                   tableCellRowspan = 1}]],
            tableHeaderRows = []})
      (DocAppend
@@ -21,6 +21,6 @@ DocAppend
              {tableBodyRows = [TableRow
                                  [TableCell
                                     {tableCellColspan = 1,
-                                     tableCellContents = DocString " inner ",
+                                     tableCellContents = DocString "inner",
                                      tableCellRowspan = 1}]],
               tableHeaderRows = []})))
diff --git a/haddock-library/fixtures/examples/table5.parsed b/haddock-library/fixtures/examples/table5.parsed
index 9a547ad3..f9a387bb 100644
--- a/haddock-library/fixtures/examples/table5.parsed
+++ b/haddock-library/fixtures/examples/table5.parsed
@@ -4,50 +4,43 @@ DocTable
                         [TableCell
                            {tableCellColspan = 1,
                             tableCellContents = DocString
-                                                  (concat
-                                                     [" row 2        \n",
-                                                      "              \n",
-                                                      "              \n",
-                                                      " row 3        "]),
+                                                  (concat ["row 2\n", "\n", "\n", "row 3"]),
                             tableCellRowspan = 2},
                          TableCell
                            {tableCellColspan = 3,
                             tableCellContents = DocAppend
-                                                  (DocString " Use the command  ")
+                                                  (DocString "Use the command  ")
                                                   (DocAppend
                                                      (DocMonospaced (DocString "ls | more"))
-                                                     (DocString
-                                                        (concat
-                                                           [".    \n",
-                                                            "                                  "]))),
+                                                     (DocString ".\n")),
                             tableCellRowspan = 1}],
                       TableRow
                         [TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString "          ",
+                            tableCellContents = DocEmpty,
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString "           ",
+                            tableCellContents = DocEmpty,
                             tableCellRowspan = 1},
                          TableCell
                            {tableCellColspan = 1,
-                            tableCellContents = DocString "           ",
+                            tableCellContents = DocEmpty,
                             tableCellRowspan = 1}]],
      tableHeaderRows = [TableRow
                           [TableCell
                              {tableCellColspan = 1,
-                              tableCellContents = DocString " row 1, col 1 ",
+                              tableCellContents = DocString "row 1, col 1",
                               tableCellRowspan = 1},
                            TableCell
                              {tableCellColspan = 1,
-                              tableCellContents = DocString " column 2 ",
+                              tableCellContents = DocString "column 2",
                               tableCellRowspan = 1},
                            TableCell
                              {tableCellColspan = 1,
-                              tableCellContents = DocString " column 3  ",
+                              tableCellContents = DocString "column 3",
                               tableCellRowspan = 1},
                            TableCell
                              {tableCellColspan = 1,
-                              tableCellContents = DocString " column 4  ",
+                              tableCellContents = DocString "column 4",
                               tableCellRowspan = 1}]]}
diff --git a/haddock-library/haddock-library.cabal b/haddock-library/haddock-library.cabal
index ef802a64..490dff10 100644
--- a/haddock-library/haddock-library.cabal
+++ b/haddock-library/haddock-library.cabal
@@ -1,6 +1,6 @@
 cabal-version:        2.2
 name:                 haddock-library
-version:              1.8.0
+version:              1.9.0
 synopsis:             Library exposing some functionality of Haddock.
 
 description:          Haddock is a documentation-generation tool for Haskell
@@ -12,15 +12,27 @@ description:          Haddock is a documentation-generation tool for Haskell
                       itself, see the [haddock package](https://hackage.haskell.org/package/haddock).
 
 license:              BSD-2-Clause
-license-files:        LICENSE
+license-file:         LICENSE
 maintainer:           Alec Theriault <alec.theriault@gmail.com>, Alex Biehl <alexbiehl@gmail.com>, Simon Hengel <sol@typeful.net>, Mateusz Kowalczyk <fuuzetsu@fuuzetsu.co.uk>
 homepage:             http://www.haskell.org/haddock/
 bug-reports:          https://github.com/haskell/haddock/issues
 category:             Documentation
-tested-with:          GHC==8.12.*, GHC==8.10.*, GHC==8.8.1
+tested-with:          GHC == 7.4.2
+                    , GHC == 7.6.3
+                    , GHC == 7.8.4
+                    , GHC == 7.10.3
+                    , GHC == 8.0.2
+                    , GHC == 8.2.2
+                    , GHC == 8.4.4
+                    , GHC == 8.6.5
+                    , GHC == 8.8.3
+                    , GHC == 8.10.1
+                    , GHC == 9.0.1
 
 extra-source-files:
   CHANGES.md
+  fixtures/examples/*.input
+  fixtures/examples/*.parsed
 
 common lib-defaults
   default-language: Haskell2010
@@ -33,9 +45,9 @@ common lib-defaults
     , text         ^>= 1.2.3.0
     , parsec       ^>= 3.1.13.0
 
-  ghc-options: -funbox-strict-fields -Wall -fwarn-tabs
+  ghc-options: -funbox-strict-fields -Wall
   if impl(ghc >= 8.0)
-    ghc-options: -Wcompat -Wnoncanonical-monad-instances -Wnoncanonical-monadfail-instances
+    ghc-options: -Wcompat -Wnoncanonical-monad-instances
 
 library
   import: lib-defaults
@@ -49,33 +61,34 @@ library
     Documentation.Haddock.Types
 
   other-modules:
+    CompatPrelude
     Documentation.Haddock.Parser.Util
     Documentation.Haddock.Parser.Monad
+    Documentation.Haddock.Parser.Identifier
 
 test-suite spec
   import: lib-defaults
   type:             exitcode-stdio-1.0
   main-is:          Spec.hs
   hs-source-dirs:
-      test
-      src
-
-  cpp-options:
-      -DTEST
+    test
+    src
 
   other-modules:
-      Documentation.Haddock.Doc
-      Documentation.Haddock.Markup
-      Documentation.Haddock.Parser
-      Documentation.Haddock.Parser.Monad
-      Documentation.Haddock.Parser.Util
-      Documentation.Haddock.Parser.UtilSpec
-      Documentation.Haddock.ParserSpec
-      Documentation.Haddock.Types
+    CompatPrelude
+    Documentation.Haddock.Doc
+    Documentation.Haddock.Markup
+    Documentation.Haddock.Parser
+    Documentation.Haddock.Parser.Monad
+    Documentation.Haddock.Parser.Util
+    Documentation.Haddock.Parser.UtilSpec
+    Documentation.Haddock.ParserSpec
+    Documentation.Haddock.Types
+    Documentation.Haddock.Parser.Identifier
 
   build-depends:
-    , base-compat  ^>= 0.9.3 || ^>= 0.10.0
-    , QuickCheck   ^>= 2.11.3
+    , base-compat  ^>= 0.9.3 || ^>= 0.11.0
+    , QuickCheck   ^>= 2.11  || ^>= 2.13.2 || ^>= 2.14 
     , deepseq      ^>= 1.3.0.0 || ^>= 1.4.0.0
 
   -- NB: build-depends & build-tool-depends have independent
@@ -83,10 +96,10 @@ test-suite spec
   --     version of `hspec` & `hspec-discover` to ensure
   --     intercompatibility
   build-depends:
-    , hspec                         ^>= 2.5.5
+    , hspec                          >= 2.4.4    && < 2.8
 
   build-tool-depends:
-    , hspec-discover:hspec-discover ^>= 2.5.5
+    , hspec-discover:hspec-discover  >= 2.4.4    && < 2.8
 
 test-suite fixtures
   type:             exitcode-stdio-1.0
@@ -94,7 +107,6 @@ test-suite fixtures
   main-is:          Fixtures.hs
   ghc-options:      -Wall
   hs-source-dirs:   fixtures
-  buildable:        False
   build-depends:
       -- intra-package dependency
     , haddock-library
@@ -102,11 +114,11 @@ test-suite fixtures
     , base
 
       -- extra dependencies
-    , base-compat  >= 0.9.3   && < 0.11
+    , base-compat           ^>= 0.9.3 || ^>= 0.11.0
     , directory             ^>= 1.3.0.2
     , filepath              ^>= 1.4.1.2
-    , optparse-applicative  ^>= 0.14.0.0
-    , tree-diff             ^>= 0.0.0.1
+    , optparse-applicative  ^>= 0.15
+    , tree-diff             ^>= 0.1
 
 source-repository head
   type:     git
diff --git a/haddock-library/src/CompatPrelude.hs b/haddock-library/src/CompatPrelude.hs
new file mode 100644
index 00000000..60fa94d9
--- /dev/null
+++ b/haddock-library/src/CompatPrelude.hs
@@ -0,0 +1,52 @@
+{-# LANGUAGE CPP #-}
+
+#if !MIN_VERSION_base(4,5,0)
+# error This module doesn't provide compat-shims for versions prior to base-4.5
+#endif
+
+-- | Bridge impedance mismatch of different @base@ versions back till @base-4.5@ (GHC 7.4.2)
+module CompatPrelude
+    ( ($>)
+    , isSymbolChar
+    ) where
+
+#if MIN_VERSION_base(4,7,0)
+import           Data.Functor                ( ($>) )
+#else
+import           Data.Functor                ( (<$) )
+#endif
+
+#if MIN_VERSION_base(4,9,0)
+import           Text.Read.Lex                      (isSymbolChar)
+#else
+import           Data.Char (GeneralCategory(..), generalCategory)
+#endif
+
+
+#if !MIN_VERSION_base(4,7,0)
+infixl 4 $>
+
+-- | Flipped version of '<$'.
+--
+-- @since 4.7.0.0
+($>) :: Functor f => f a -> b -> f b
+($>) = flip (<$)
+#endif
+
+#if !MIN_VERSION_base(4,9,0)
+-- inlined from base-4.10.0.0
+isSymbolChar :: Char -> Bool
+isSymbolChar c = not (isPuncChar c) && case generalCategory c of
+    MathSymbol           -> True
+    CurrencySymbol       -> True
+    ModifierSymbol       -> True
+    OtherSymbol          -> True
+    DashPunctuation      -> True
+    OtherPunctuation     -> c `notElem` "'\""
+    ConnectorPunctuation -> c /= '_'
+    _                    -> False
+  where
+    -- | The @special@ character class as defined in the Haskell Report.
+    isPuncChar :: Char -> Bool
+    isPuncChar = (`elem` (",;()[]{}`" :: String))
+#endif
diff --git a/haddock-library/src/Documentation/Haddock/Parser.hs b/haddock-library/src/Documentation/Haddock/Parser.hs
index 82d65a0a..a3bba38a 100644
--- a/haddock-library/src/Documentation/Haddock/Parser.hs
+++ b/haddock-library/src/Documentation/Haddock/Parser.hs
@@ -1,4 +1,3 @@
-{-# LANGUAGE CPP               #-}
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE ViewPatterns      #-}
 -- |
@@ -27,7 +26,7 @@ module Documentation.Haddock.Parser (
 import           Control.Applicative
 import           Control.Arrow (first)
 import           Control.Monad
-import           Data.Char (chr, isUpper, isAlpha, isAlphaNum, isSpace)
+import           Data.Char (chr, isUpper, isAlpha, isSpace)
 import           Data.List (intercalate, unfoldr, elemIndex)
 import           Data.Maybe (fromMaybe, mapMaybe)
 import           Data.Monoid
@@ -36,6 +35,7 @@ import           Documentation.Haddock.Doc
 import           Documentation.Haddock.Markup ( markup, plainMarkup )
 import           Documentation.Haddock.Parser.Monad
 import           Documentation.Haddock.Parser.Util
+import           Documentation.Haddock.Parser.Identifier
 import           Documentation.Haddock.Types
 import           Prelude hiding (takeWhile)
 import qualified Prelude as P
@@ -46,53 +46,26 @@ import           Text.Parsec (try)
 import qualified Data.Text as T
 import           Data.Text (Text)
 
-#if MIN_VERSION_base(4,9,0)
-import           Text.Read.Lex                      (isSymbolChar)
-#else
-import           Data.Char                          (GeneralCategory (..),
-                                                     generalCategory)
-#endif
 
 -- $setup
 -- >>> :set -XOverloadedStrings
 
-#if !MIN_VERSION_base(4,9,0)
--- inlined from base-4.10.0.0
-isSymbolChar :: Char -> Bool
-isSymbolChar c = not (isPuncChar c) && case generalCategory c of
-    MathSymbol           -> True
-    CurrencySymbol       -> True
-    ModifierSymbol       -> True
-    OtherSymbol          -> True
-    DashPunctuation      -> True
-    OtherPunctuation     -> c `notElem` ("'\"" :: String)
-    ConnectorPunctuation -> c /= '_'
-    _                    -> False
-  where
-    -- | The @special@ character class as defined in the Haskell Report.
-    isPuncChar :: Char -> Bool
-    isPuncChar = (`elem` (",;()[]{}`" :: String))
-#endif
-
--- | Identifier string surrounded with opening and closing quotes/backticks.
-type Identifier = (Char, String, Char)
-
 -- | Drops the quotes/backticks around all identifiers, as if they
 -- were valid but still 'String's.
 toRegular :: DocH mod Identifier -> DocH mod String
-toRegular = fmap (\(_, x, _) -> x)
+toRegular = fmap (\(Identifier _ _ x _) -> x)
 
 -- | Maps over 'DocIdentifier's over 'String' with potentially failing
 -- conversion using user-supplied function. If the conversion fails,
 -- the identifier is deemed to not be valid and is treated as a
 -- regular string.
-overIdentifier :: (String -> Maybe a)
+overIdentifier :: (Namespace -> String -> Maybe a)
                -> DocH mod Identifier
                -> DocH mod a
 overIdentifier f d = g d
   where
-    g (DocIdentifier (o, x, e)) = case f x of
-      Nothing -> DocString $ o : x ++ [e]
+    g (DocIdentifier (Identifier ns o x e)) = case f ns x of
+      Nothing -> DocString $ renderNs ns ++ [o] ++ x ++ [e]
       Just x' -> DocIdentifier x'
     g DocEmpty = DocEmpty
     g (DocAppend x x') = DocAppend (g x) (g x')
@@ -254,7 +227,7 @@ takeWhile1_ = mfilter (not . T.null) . takeWhile_
 -- DocAName "Hello world"
 anchor :: Parser (DocH mod a)
 anchor = DocAName . T.unpack <$>
-         disallowNewline ("#" *> takeWhile1_ (/= '#') <* "#")
+         ("#" *> takeWhile1_ (\x -> x /= '#' && not (isSpace x)) <* "#")
 
 -- | Monospaced strings.
 --
@@ -269,12 +242,18 @@ monospace = DocMonospaced . parseParagraph
 -- Note that we allow '#' and '\' to support anchors (old style anchors are of
 -- the form "SomeModule\#anchor").
 moduleName :: Parser (DocH mod a)
-moduleName = DocModule <$> ("\"" *> modid <* "\"")
+moduleName = DocModule <$> ("\"" *> (modid `maybeFollowedBy` anchor_) <* "\"")
   where
     modid = intercalate "." <$> conid `Parsec.sepBy1` "."
+    anchor_ = (++)
+      <$> (Parsec.string "#" <|> Parsec.string "\\#")
+      <*> many (Parsec.satisfy (\c -> c /= '"' && not (isSpace c)))
+
+    maybeFollowedBy pre suf = (\x -> maybe x (x ++)) <$> pre <*> optional suf
+
     conid = (:)
       <$> Parsec.satisfy (\c -> isAlpha c && isUpper c)
-      <*> many (conChar <|> Parsec.oneOf "\\#")
+      <*> many conChar
 
     conChar = Parsec.alphaNum <|> Parsec.char '_'
 
@@ -294,7 +273,7 @@ picture = DocPic . makeLabeled Picture
 -- >>> parseString "\\(\\int_{-\\infty}^{\\infty} e^{-x^2/2} = \\sqrt{2\\pi}\\)"
 -- DocMathInline "\\int_{-\\infty}^{\\infty} e^{-x^2/2} = \\sqrt{2\\pi}"
 mathInline :: Parser (DocH mod a)
-mathInline = DocMathInline . T.unpack 
+mathInline = DocMathInline . T.unpack
              <$> disallowNewline  ("\\(" *> takeUntil "\\)")
 
 -- | Display math parser, surrounded by \\[ and \\].
@@ -314,7 +293,8 @@ markdownImage :: Parser (DocH mod Identifier)
 markdownImage = DocPic . fromHyperlink <$> ("!" *> linkParser)
   where
     fromHyperlink (Hyperlink u l) = Picture u (fmap (markup stringMarkup) l)
-    stringMarkup = plainMarkup (const "") (\(l,c,r) -> [l] <> c <> [r])
+    stringMarkup = plainMarkup (const "") renderIdent
+    renderIdent (Identifier ns l c r) = renderNs ns <> [l] <> c <> [r]
 
 -- | Paragraph parser, called by 'parseParas'.
 paragraph :: Parser (DocH mod Identifier)
@@ -518,7 +498,7 @@ tableStepFour rs hdrIndex cells =  case hdrIndex of
     -- extract cell contents given boundaries
     extract :: Int -> Int -> Int -> Int -> Text
     extract x y x2 y2 = T.intercalate "\n"
-        [ T.take (x2 - x + 1) $ T.drop x $ rs !! y'
+        [ T.stripEnd $ T.stripStart $ T.take (x2 - x + 1) $ T.drop x $ rs !! y'
         | y' <- [y .. y2]
         ]
 
@@ -538,11 +518,11 @@ since = ("@since " *> version <* skipHorizontalSpace <* endOfLine) >>= setSince
 header :: Parser (DocH mod Identifier)
 header = do
   let psers = map (string . flip T.replicate "=") [6, 5 .. 1]
-      pser = choice' psers
-  delim <- T.unpack <$> pser
-  line <- skipHorizontalSpace *> nonEmptyLine >>= return . parseText
+      pser = Parsec.choice psers
+  depth <- T.length <$> pser
+  line <- parseText <$> (skipHorizontalSpace *> nonEmptyLine)
   rest <- try paragraph <|> return DocEmpty
-  return $ DocHeader (Header (length delim) line) `docAppend` rest
+  return $ DocHeader (Header depth line) `docAppend` rest
 
 textParagraph :: Parser (DocH mod Identifier)
 textParagraph = parseText . T.intercalate "\n" <$> some nonEmptyLine
@@ -605,7 +585,7 @@ definitionList indent = DocDefList <$> p
         Right i -> (label, contents) : i
 
 -- | Drops all trailing newlines.
-dropNLs :: Text -> Text 
+dropNLs :: Text -> Text
 dropNLs = T.dropWhileEnd (== '\n')
 
 -- | Main worker for 'innerList' and 'definitionList'.
@@ -679,7 +659,7 @@ takeNonEmptyLine = do
 --
 -- More precisely: skips all whitespace-only lines and returns indentation
 -- (horizontal space, might be empty) of that non-empty line.
-takeIndent :: Parser Text 
+takeIndent :: Parser Text
 takeIndent = do
   indent <- takeHorizontalSpace
   choice' [ "\n" *> takeIndent
@@ -737,14 +717,14 @@ examples = DocExamples <$> (many (try (skipHorizontalSpace *> "\n")) *> go)
         substituteBlankLine "<BLANKLINE>" = ""
         substituteBlankLine xs = xs
 
-nonEmptyLine :: Parser Text 
+nonEmptyLine :: Parser Text
 nonEmptyLine = try (mfilter (T.any (not . isSpace)) takeLine)
 
 takeLine :: Parser Text
 takeLine = try (takeWhile (/= '\n') <* endOfLine)
 
 endOfLine :: Parser ()
-endOfLine = void "\n" <|> Parsec.eof 
+endOfLine = void "\n" <|> Parsec.eof
 
 -- | Property parser.
 --
@@ -826,7 +806,7 @@ autoUrl :: Parser (DocH mod a)
 autoUrl = mkLink <$> url
   where
     url = mappend <$> choice' [ "http://", "https://", "ftp://"] <*> takeWhile1 (not . isSpace)
-    
+
     mkLink :: Text -> DocH mod a
     mkLink s = case T.unsnoc s of
       Just (xs,x) | x `elem` (",.!?" :: String) -> DocHyperlink (mkHyperlink xs) `docAppend` DocString [x]
@@ -836,30 +816,6 @@ autoUrl = mkLink <$> url
     mkHyperlink lnk = Hyperlink (T.unpack lnk) Nothing
 
 
-
--- | Parses strings between identifier delimiters. Consumes all input that it
--- deems to be valid in an identifier. Note that it simply blindly consumes
--- characters and does no actual validation itself.
-parseValid :: Parser String
-parseValid = p some
-  where
-    idChar = Parsec.satisfy (\c -> isAlphaNum c || isSymbolChar c || c == '_')
-
-    p p' = do
-      vs <- p' idChar
-      c <- peekChar'
-      case c of
-        '`' -> return vs
-        '\'' -> choice' [ (\x -> vs ++ "'" ++ x) <$> ("'" *> p many), return vs ]
-        _ -> fail "outofvalid"
-
--- | Parses identifiers with help of 'parseValid'. Asks GHC for
--- 'String' from the string it deems valid.
+-- | Parses identifiers with help of 'parseValid'.
 identifier :: Parser (DocH mod Identifier)
-identifier = do
-  o <- idDelim
-  vid <- parseValid
-  e <- idDelim
-  return $ DocIdentifier (o, vid, e)
-  where
-    idDelim = Parsec.satisfy (\c -> c == '\'' || c == '`')
+identifier = DocIdentifier <$> parseValid
diff --git a/haddock-library/src/Documentation/Haddock/Parser/Identifier.hs b/haddock-library/src/Documentation/Haddock/Parser/Identifier.hs
new file mode 100644
index 00000000..b8afb951
--- /dev/null
+++ b/haddock-library/src/Documentation/Haddock/Parser/Identifier.hs
@@ -0,0 +1,160 @@
+{-# LANGUAGE BangPatterns #-}
+{-# LANGUAGE ViewPatterns #-}
+-- |
+-- Module      :  Documentation.Haddock.Parser.Identifier
+-- Copyright   :  (c) Alec Theriault 2019,
+-- License     :  BSD-like
+--
+-- Maintainer  :  haddock@projects.haskell.org
+-- Stability   :  experimental
+-- Portability :  portable
+--
+-- Functionality for parsing identifiers and operators
+
+module Documentation.Haddock.Parser.Identifier (
+  Identifier(..),
+  parseValid,
+) where
+
+import Documentation.Haddock.Types           ( Namespace(..) )
+import Documentation.Haddock.Parser.Monad
+import qualified Text.Parsec as Parsec
+import           Text.Parsec.Pos             ( updatePosChar )
+import           Text.Parsec                 ( State(..)
+                                             , getParserState, setParserState )
+
+import Data.Text (Text)
+import qualified Data.Text as T
+
+import           Data.Char (isAlpha, isAlphaNum)
+import Control.Monad (guard)
+import Data.Maybe
+import CompatPrelude
+
+-- | Identifier string surrounded with namespace, opening, and closing quotes/backticks.
+data Identifier = Identifier !Namespace !Char String !Char
+  deriving (Show, Eq)
+
+parseValid :: Parser Identifier
+parseValid = do
+  s@State{ stateInput = inp, statePos = pos } <- getParserState
+
+  case takeIdentifier inp of
+    Nothing -> Parsec.parserFail "parseValid: Failed to match a valid identifier"
+    Just (ns, op, ident, cl, inp') ->
+      let posOp = updatePosChar pos op
+          posIdent = T.foldl updatePosChar posOp ident
+          posCl = updatePosChar posIdent cl
+          s' = s{ stateInput = inp', statePos = posCl }
+      in setParserState s' $> Identifier ns op (T.unpack ident) cl
+
+
+-- | Try to parse a delimited identifier off the front of the given input.
+--
+-- This tries to match as many valid Haskell identifiers/operators as possible,
+-- to the point of sometimes accepting invalid things (ex: keywords). Some
+-- considerations:
+--
+--   - operators and identifiers can have module qualifications
+--   - operators can be wrapped in parens (for prefix)
+--   - identifiers can be wrapped in backticks (for infix)
+--   - delimiters are backticks or regular ticks
+--   - since regular ticks are also valid in identifiers, we opt for the
+--     longest successful parse
+--
+-- This function should make /O(1)/ allocations
+takeIdentifier :: Text -> Maybe (Namespace, Char, Text, Char, Text)
+takeIdentifier input = listToMaybe $ do
+
+    -- Optional namespace
+    let (ns, input') = case T.uncons input of
+                         Just ('v', i) -> (Value, i)
+                         Just ('t', i) -> (Type, i)
+                         _             -> (None, input)
+
+    -- Opening tick
+    (op, input'') <- maybeToList (T.uncons input')
+    guard (op == '\'' || op == '`')
+
+    -- Identifier/operator
+    (ident, input''') <- wrapped input''
+
+    -- Closing tick
+    (cl, input'''') <- maybeToList (T.uncons input''')
+    guard (cl == '\'' || cl == '`')
+
+    return (ns, op, ident, cl, input'''')
+
+  where
+
+    -- | Parse out a wrapped, possibly qualified, operator or identifier
+    wrapped t = do
+      (c, t'  ) <- maybeToList (T.uncons t)
+      -- Tuples
+      case c of
+        '(' | Just (c', _) <- T.uncons t'
+            , c' == ',' || c' == ')'
+            -> do let (commas, t'') = T.span (== ',') t'
+                  (')', t''') <- maybeToList (T.uncons t'')
+                  return (T.take (T.length commas + 2) t, t''')
+
+        -- Parenthesized
+        '(' -> do (n,   t'' ) <- general False 0 [] t'
+                  (')', t''') <- maybeToList (T.uncons t'')
+                  return (T.take (n + 2) t, t''')
+
+        -- Backticked
+        '`' -> do (n,   t'' ) <- general False 0 [] t'
+                  ('`', t''') <- maybeToList (T.uncons t'')
+                  return (T.take (n + 2) t, t''')
+
+        -- Unadorned
+        _   -> do (n,   t'' ) <- general False 0 [] t
+                  return (T.take n t, t'')
+
+    -- | Parse out a possibly qualified operator or identifier
+    general :: Bool           -- ^ refuse inputs starting with operators
+            -> Int            -- ^ total characters \"consumed\" so far
+            -> [(Int, Text)]  -- ^ accumulated results
+            -> Text           -- ^ current input
+            -> [(Int, Text)]  -- ^ total characters parsed & what remains
+    general !identOnly !i acc t
+      -- Starts with an identifier (either just an identifier, or a module qual)
+      | Just (n, rest) <- identLike t
+      = if T.null rest
+          then acc
+          else case T.head rest of
+                 '`' -> (n + i, rest) : acc
+                 ')' -> (n + i, rest) : acc
+                 '.' -> general False (n + i + 1) acc (T.tail rest)
+                 '\'' -> let (m, rest') = quotes rest
+                         in general True (n + m + 1 + i) ((n + m + i, rest') : acc) (T.tail rest')
+                 _ -> acc
+
+      -- An operator
+      | Just (n, rest) <- optr t
+      , not identOnly
+      = (n + i, rest) : acc
+
+      -- Anything else
+      | otherwise
+      = acc
+
+    -- | Parse an identifier off the front of the input
+    identLike t
+      | T.null t = Nothing
+      | isAlpha (T.head t) || '_' == T.head t
+      = let !(idt, rest) = T.span (\c -> isAlphaNum c || c == '_') t
+            !(octos, rest') = T.span (== '#') rest
+      in Just (T.length idt + T.length octos, rest')
+      | otherwise = Nothing
+
+    -- | Parse all but the last quote off the front of the input
+    -- PRECONDITION: T.head t == '\''
+    quotes :: Text -> (Int, Text)
+    quotes t = let !n = T.length (T.takeWhile (== '\'') t) - 1
+               in (n, T.drop n t)
+
+    -- | Parse an operator off the front of the input
+    optr t = let !(op, rest) = T.span isSymbolChar t
+             in if T.null op then Nothing else Just (T.length op, rest)
diff --git a/haddock-library/src/Documentation/Haddock/Parser/Monad.hs b/haddock-library/src/Documentation/Haddock/Parser/Monad.hs
index 8f5bd217..7c73a168 100644
--- a/haddock-library/src/Documentation/Haddock/Parser/Monad.hs
+++ b/haddock-library/src/Documentation/Haddock/Parser/Monad.hs
@@ -4,6 +4,18 @@
 {-# LANGUAGE TypeFamilies #-}
 {-# LANGUAGE BangPatterns #-}
 {-# LANGUAGE TypeSynonymInstances #-}
+-- |
+-- Module      :  Documentation.Haddock.Parser.Monad
+-- Copyright   :  (c) Alec Theriault 2018-2019,
+-- License     :  BSD-like
+--
+-- Maintainer  :  haddock@projects.haskell.org
+-- Stability   :  experimental
+-- Portability :  portable
+--
+-- Defines the Parsec monad over which all parsing is done and also provides
+-- more efficient versions of the usual parsec combinator functions (but
+-- specialized to 'Text').
 
 module Documentation.Haddock.Parser.Monad where
 
@@ -17,7 +29,6 @@ import qualified Data.Text as T
 import           Data.Text                   ( Text )
 
 import           Control.Monad               ( mfilter )
-import           Data.Functor                ( ($>) )
 import           Data.String                 ( IsString(..) )
 import           Data.Bits                   ( Bits(..) )
 import           Data.Char                   ( ord )
@@ -25,7 +36,9 @@ import           Data.List                   ( foldl' )
 import           Control.Applicative as App
 
 import           Documentation.Haddock.Types ( Version )
+
 import           Prelude hiding (takeWhile)
+import           CompatPrelude
 
 -- | The only bit of information we really care about truding along with us
 -- through parsing is the version attached to a @\@since@ annotation - if
@@ -96,7 +109,6 @@ takeWhile f = do
       s' = s{ stateInput = inp', statePos = pos' }
   setParserState s' $> t
 
-
 -- | Like 'takeWhile', but fails if no characters matched.
 --
 -- Equivalent to @fmap T.pack . Parsec.many1@, but more efficient.
diff --git a/haddock-library/src/Documentation/Haddock/Parser/Util.hs b/haddock-library/src/Documentation/Haddock/Parser/Util.hs
index 98570c22..eef744d8 100644
--- a/haddock-library/src/Documentation/Haddock/Parser/Util.hs
+++ b/haddock-library/src/Documentation/Haddock/Parser/Util.hs
@@ -31,16 +31,16 @@ import           Prelude hiding (takeWhile)
 import           Data.Char (isSpace)
 
 -- | Characters that count as horizontal space
-horizontalSpace :: [Char]
-horizontalSpace = " \t\f\v\r"
+horizontalSpace :: Char -> Bool
+horizontalSpace c = isSpace c && c /= '\n'
 
 -- | Skip and ignore leading horizontal space
 skipHorizontalSpace :: Parser ()
-skipHorizontalSpace = Parsec.skipMany (Parsec.oneOf horizontalSpace)
+skipHorizontalSpace = Parsec.skipMany (Parsec.satisfy horizontalSpace)
 
 -- | Take leading horizontal space
-takeHorizontalSpace :: Parser Text 
-takeHorizontalSpace = takeWhile (`elem` horizontalSpace)
+takeHorizontalSpace :: Parser Text
+takeHorizontalSpace = takeWhile horizontalSpace
 
 makeLabeled :: (String -> Maybe String -> a) -> Text -> a
 makeLabeled f input = case T.break isSpace $ removeEscapes $ T.strip input of
@@ -60,10 +60,10 @@ removeEscapes = T.unfoldr go
 
 -- | Consume characters from the input up to and including the given pattern.
 -- Return everything consumed except for the end pattern itself.
-takeUntil :: Text -> Parser Text 
+takeUntil :: Text -> Parser Text
 takeUntil end_ = T.dropEnd (T.length end_) <$> requireEnd (scan p (False, end)) >>= gotSome
   where
-    end = T.unpack end_ 
+    end = T.unpack end_
 
     p :: (Bool, String) -> Char -> Maybe (Bool, String)
     p acc c = case acc of
diff --git a/haddock-library/src/Documentation/Haddock/Types.hs b/haddock-library/src/Documentation/Haddock/Types.hs
index f8f7d353..12ccd28d 100644
--- a/haddock-library/src/Documentation/Haddock/Types.hs
+++ b/haddock-library/src/Documentation/Haddock/Types.hs
@@ -44,14 +44,17 @@ data MetaDoc mod id =
           } deriving (Eq, Show, Functor, Foldable, Traversable)
 
 #if MIN_VERSION_base(4,8,0)
+-- | __NOTE__: Only defined for @base >= 4.8.0@
 instance Bifunctor MetaDoc where
   bimap f g (MetaDoc m d) = MetaDoc m (bimap f g d)
 #endif
 
 #if MIN_VERSION_base(4,10,0)
+-- | __NOTE__: Only defined for @base >= 4.10.0@
 instance Bifoldable MetaDoc where
   bifoldr f g z d = bifoldr f g z (_doc d)
 
+-- | __NOTE__: Only defined for @base >= 4.10.0@
 instance Bitraversable MetaDoc where
   bitraverse f g (MetaDoc m d) = MetaDoc m <$> bitraverse f g d
 #endif
@@ -76,7 +79,7 @@ data Picture = Picture
   } deriving (Eq, Show)
 
 data Header id = Header
-  { headerLevel :: Int
+  { headerLevel :: Int  -- ^ between 1 and 6 inclusive
   , headerTitle :: id
   } deriving (Eq, Show, Functor, Foldable, Traversable)
 
@@ -123,7 +126,7 @@ data DocH mod id
   | DocMathInline String
   | DocMathDisplay String
   | DocAName String
-  -- ^ A (HTML) anchor.
+  -- ^ A (HTML) anchor. It must not contain any spaces.
   | DocProperty String
   | DocExamples [Example]
   | DocHeader (Header (DocH mod id))
@@ -131,6 +134,7 @@ data DocH mod id
   deriving (Eq, Show, Functor, Foldable, Traversable)
 
 #if MIN_VERSION_base(4,8,0)
+-- | __NOTE__: Only defined for @base >= 4.8.0@
 instance Bifunctor DocH where
   bimap _ _ DocEmpty = DocEmpty
   bimap f g (DocAppend docA docB) = DocAppend (bimap f g docA) (bimap f g docB)
@@ -159,6 +163,7 @@ instance Bifunctor DocH where
 #endif
 
 #if MIN_VERSION_base(4,10,0)
+-- | __NOTE__: Only defined for @base >= 4.10.0@
 instance Bifoldable DocH where
   bifoldr f g z (DocAppend docA docB) = bifoldr f g (bifoldr f g z docA) docB
   bifoldr f g z (DocParagraph doc) = bifoldr f g z doc
@@ -176,6 +181,7 @@ instance Bifoldable DocH where
   bifoldr f g z (DocTable (Table header body)) = foldr (\r acc -> foldr (flip (bifoldr f g)) acc r) (foldr (\r acc -> foldr (flip (bifoldr f g)) acc r) z body) header
   bifoldr _ _ z _ = z
 
+-- | __NOTE__: Only defined for @base >= 4.10.0@
 instance Bitraversable DocH where
   bitraverse _ _ DocEmpty = pure DocEmpty
   bitraverse f g (DocAppend docA docB) = DocAppend <$> bitraverse f g docA <*> bitraverse f g docB
@@ -203,6 +209,16 @@ instance Bitraversable DocH where
   bitraverse f g (DocTable (Table header body)) = (\h b -> DocTable (Table h b)) <$> traverse (traverse (bitraverse f g)) header <*> traverse (traverse (bitraverse f g)) body
 #endif
 
+-- | The namespace qualification for an identifier.
+data Namespace = Value | Type | None deriving (Eq, Ord, Enum, Show)
+
+-- | Render the a namespace into the same format it was initially parsed.
+renderNs :: Namespace -> String
+renderNs Value = "v"
+renderNs Type = "t"
+renderNs None = ""
+
+
 -- | 'DocMarkupH' is a set of instructions for marking up documentation.
 -- In fact, it's really just a mapping from 'Doc' to some other
 -- type [a], where [a] is usually the type of the output (HTML, say).
diff --git a/haddock-library/test/Documentation/Haddock/ParserSpec.hs b/haddock-library/test/Documentation/Haddock/ParserSpec.hs
index 6269184a..1724c664 100644
--- a/haddock-library/test/Documentation/Haddock/ParserSpec.hs
+++ b/haddock-library/test/Documentation/Haddock/ParserSpec.hs
@@ -3,6 +3,7 @@
 
 module Documentation.Haddock.ParserSpec (main, spec) where
 
+import           Data.Char (isSpace)
 import           Data.String
 import qualified Documentation.Haddock.Parser as Parse
 import           Documentation.Haddock.Types
@@ -112,7 +113,7 @@ spec = do
         "``" `shouldParseTo` "``"
 
       it "can parse an identifier in infix notation enclosed within backticks" $ do
-        "``infix``" `shouldParseTo` "`" <> DocIdentifier "infix" <> "`"
+        "``infix``" `shouldParseTo` DocIdentifier "`infix`"
 
       it "can parse identifiers containing a single quote" $ do
         "'don't'" `shouldParseTo` DocIdentifier "don't"
@@ -132,6 +133,19 @@ spec = do
       it "can parse an identifier that starts with an underscore" $ do
         "'_x'" `shouldParseTo` DocIdentifier "_x"
 
+      it "can parse value-namespaced identifiers" $ do
+        "v'foo'" `shouldParseTo` DocIdentifier "foo"
+
+      it "can parse type-namespaced identifiers" $ do
+        "t'foo'" `shouldParseTo` DocIdentifier "foo"
+
+      it "can parse parenthesized operators and backticked identifiers" $ do
+        "'(<|>)'" `shouldParseTo` DocIdentifier "(<|>)"
+        "'`elem`'" `shouldParseTo` DocIdentifier "`elem`"
+
+      it "can properly figure out the end of identifiers" $ do
+        "'DbModule'/'DbUnitId'" `shouldParseTo` DocIdentifier "DbModule" <> "/" <> DocIdentifier "DbUnitId"
+
     context "when parsing operators" $ do
       it "can parse an operator enclosed within single quotes" $ do
         "'.='" `shouldParseTo` DocIdentifier ".="
@@ -275,8 +289,10 @@ spec = do
       it "parses a single word anchor" $ do
         "#foo#" `shouldParseTo` DocAName "foo"
 
-      it "parses a multi word anchor" $ do
-        "#foo bar#" `shouldParseTo` DocAName "foo bar"
+      -- Spaces are not allowed:
+      -- https://www.w3.org/TR/html51/dom.html#the-id-attribute
+      it "doesn't parse a multi word anchor" $ do
+        "#foo bar#" `shouldParseTo` "#foo bar#"
 
       it "parses a unicode anchor" $ do
         "#灼眼のシャナ#" `shouldParseTo` DocAName "灼眼のシャナ"
@@ -291,6 +307,9 @@ spec = do
       it "does not accept empty anchors" $ do
         "##" `shouldParseTo` "##"
 
+      it "does not accept anchors containing spaces" $ do
+        "{-# LANGUAGE GADTs #-}" `shouldParseTo` "{-# LANGUAGE GADTs #-}"
+
     context "when parsing emphasised text" $ do
       it "emphasises a word on its own" $ do
         "/foo/" `shouldParseTo` DocEmphasis "foo"
@@ -417,6 +436,9 @@ spec = do
       it "accepts anchor reference syntax as DocModule" $ do
         "\"Foo#bar\"" `shouldParseTo` DocModule "Foo#bar"
 
+      it "accepts anchor with hyphen as DocModule" $ do
+        "\"Foo#bar-baz\"" `shouldParseTo` DocModule "Foo#bar-baz"
+
       it "accepts old anchor reference syntax as DocModule" $ do
         "\"Foo\\#bar\"" `shouldParseTo` DocModule "Foo\\#bar"
 
@@ -429,6 +451,10 @@ spec = do
       property $ \xs ->
         (length . show . parseParas) xs `shouldSatisfy` (> 0)
 
+    -- See <https://github.com/haskell/haddock/issues/1142>
+    it "doesn't crash on unicode whitespace" $ do
+      "\8197" `shouldParseTo` DocEmpty
+
     context "when parsing @since" $ do
       it "adds specified version to the result" $ do
         parseParas "@since 0.5.0" `shouldBe`
@@ -457,7 +483,8 @@ spec = do
 
 
     context "when parsing text paragraphs" $ do
-      let filterSpecial = filter (`notElem` (".(=#-[*`\v\f\n\t\r\\\"'_/@<> " :: String))
+      let isSpecial c = isSpace c || c `elem` (".(=#-[*`\\\"'_/@<>" :: String)
+          filterSpecial = filter (not . isSpecial)
 
       it "parses an empty paragraph" $ do
         "" `shouldParseTo` DocEmpty