Use Control.Monad.State.Strict throughout.

This gives 20-30% speedup and reduction of memory
usage in most of the writers.

Makefile

@@ -16,7 +16,7 @@ test:
 	stack test --flag 'pandoc:embed_data_files' --fast --test-arguments='-j4 --hide-successes $(TESTARGS)'
 
 bench:
-	stack bench
+	stack bench --benchmark-arguments='$(BENCHARGS)'
 
 weigh:
 	stack build --flag 'pandoc:weigh-pandoc' && stack exec weigh-pandoc

src/Text/Pandoc/Class.hs

@@ -107,7 +107,7 @@ import qualified System.FilePath.Glob as IO (glob)
 import qualified System.Directory as IO (getModificationTime)
 import Control.Monad as M (fail)
 import Control.Monad.Reader (ReaderT)
-import Control.Monad.State
+import Control.Monad.State.Strict
 import Control.Monad.Except
 import Control.Monad.Writer (WriterT)
 import Control.Monad.RWS (RWST)

src/Text/Pandoc/Pretty.hs

@@ -77,7 +77,7 @@ module Text.Pandoc.Pretty (
      )
 
 where
-import Control.Monad.State
+import Control.Monad.State.Strict
 import Data.Char (isSpace)
 import Data.Foldable (toList)
 import Data.List (intersperse)

src/Text/Pandoc/Readers/DocBook.hs

@@ -9,7 +9,7 @@ import Text.HTML.TagSoup.Entity (lookupEntity)
 import Data.Either (rights)
 import Data.Generics
 import Data.Char (isSpace)
-import Control.Monad.State
+import Control.Monad.State.Strict
 import Data.List (intersperse)
 import Data.Maybe (fromMaybe)
 import Text.TeXMath (readMathML, writeTeX)

src/Text/Pandoc/Readers/Docx.hs

@@ -76,7 +76,7 @@ module Text.Pandoc.Readers.Docx
 
 import Codec.Archive.Zip
 import Control.Monad.Reader
-import Control.Monad.State
+import Control.Monad.State.Strict
 import qualified Data.ByteString.Lazy as B
 import Data.Default (Default)
 import Data.List (delete, intersect)

src/Text/Pandoc/Readers/Docx/Parse.hs

@@ -58,7 +58,7 @@ import Codec.Archive.Zip
 import Control.Applicative ((<|>))
 import Control.Monad.Except
 import Control.Monad.Reader
-import Control.Monad.State
+import Control.Monad.State.Strict
 import Data.Bits ((.|.))
 import qualified Data.ByteString.Lazy as B
 import Data.Char (chr, isDigit, ord, readLitChar)

src/Text/Pandoc/Readers/Docx/StyleMap.hs

@@ -7,7 +7,7 @@ module Text.Pandoc.Readers.Docx.StyleMap (  StyleMaps(..)
                                           , hasStyleName
                                           ) where
 
-import Control.Monad.State
+import Control.Monad.State.Strict
 import Data.Char (toLower)
 import qualified Data.Map as M
 import Text.Pandoc.Readers.Docx.Util

src/Text/Pandoc/Readers/OPML.hs

@@ -1,6 +1,6 @@
 {-# LANGUAGE FlexibleContexts #-}
 module Text.Pandoc.Readers.OPML ( readOPML ) where
-import Control.Monad.State
+import Control.Monad.State.Strict
 import Data.Char (toUpper)
 import Data.Text (Text, unpack, pack)
 import Data.Default

src/Text/Pandoc/Shared.hs

@@ -117,7 +117,7 @@ import Text.Pandoc.MIME (MimeType)
 import Text.Pandoc.Error (PandocError(..))
 import System.FilePath ( (</>) )
 import Data.Generics (Typeable, Data)
-import qualified Control.Monad.State as S
+import qualified Control.Monad.State.Strict as S
 import qualified Control.Exception as E
 import Control.Monad (msum, unless, MonadPlus(..))
 import Text.Pandoc.Pretty (charWidth)

src/Text/Pandoc/Writers/AsciiDoc.hs

@@ -37,7 +37,7 @@ that it has omitted the construct.
 AsciiDoc:  <http://www.methods.co.nz/asciidoc/>
 -}
 module Text.Pandoc.Writers.AsciiDoc (writeAsciiDoc) where
-import Control.Monad.State
+import Control.Monad.State.Strict
 import Data.Aeson (Result (..), Value (String), fromJSON, toJSON)
 import Data.Char (isPunctuation, isSpace)
 import Data.List (intercalate, intersperse, stripPrefix)

src/Text/Pandoc/Writers/CommonMark.hs

@@ -32,7 +32,7 @@ CommonMark:  <http://commonmark.org>
 module Text.Pandoc.Writers.CommonMark (writeCommonMark) where
 
 import CMark
-import Control.Monad.State (State, get, modify, runState)
+import Control.Monad.State.Strict (State, get, modify, runState)
 import Data.Foldable (foldrM)
 import Data.Text (Text)
 import qualified Data.Text as T

src/Text/Pandoc/Writers/ConTeXt.hs

@@ -29,7 +29,7 @@ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 Conversion of 'Pandoc' format into ConTeXt.
 -}
 module Text.Pandoc.Writers.ConTeXt ( writeConTeXt ) where
-import Control.Monad.State
+import Control.Monad.State.Strict
 import Data.Char (ord)
 import Data.List (intercalate, intersperse)
 import Data.Maybe (catMaybes)

src/Text/Pandoc/Writers/Docx.hs

@@ -37,7 +37,7 @@ import Codec.Archive.Zip
 import Control.Applicative ((<|>))
 import Control.Monad.Except (catchError)
 import Control.Monad.Reader
-import Control.Monad.State
+import Control.Monad.State.Strict
 import qualified Data.ByteString as B
 import qualified Data.ByteString.Lazy as BL
 import qualified Data.ByteString.Lazy.Char8 as BL8

src/Text/Pandoc/Writers/DokuWiki.hs

@@ -41,7 +41,7 @@ DokuWiki:  <https://www.dokuwiki.org/dokuwiki>
 module Text.Pandoc.Writers.DokuWiki ( writeDokuWiki ) where
 import Control.Monad (zipWithM)
 import Control.Monad.Reader (ReaderT, ask, local, runReaderT)
-import Control.Monad.State (StateT, evalStateT, gets, modify)
+import Control.Monad.State.Strict (StateT, evalStateT, gets, modify)
 import Data.Default (Default (..))
 import Data.List (intercalate, intersect, isPrefixOf, transpose)
 import Data.Text (Text, pack)

src/Text/Pandoc/Writers/EPUB.hs

@@ -36,7 +36,7 @@ import Codec.Archive.Zip (Entry, addEntryToArchive, eRelativePath, emptyArchive,
                           fromArchive, fromEntry, toEntry)
 import Control.Monad (mplus, when, zipWithM)
 import Control.Monad.Except (catchError, throwError)
-import Control.Monad.State (State, StateT, evalState, evalStateT, get, gets,
+import Control.Monad.State.Strict (State, StateT, evalState, evalStateT, get, gets,
                             lift, modify, put)
 import qualified Data.ByteString.Lazy as B
 import qualified Data.ByteString.Lazy.Char8 as B8

src/Text/Pandoc/Writers/FB2.hs

@@ -38,8 +38,8 @@ FictionBook is an XML-based e-book format. For more information see:
 module Text.Pandoc.Writers.FB2 (writeFB2)  where
 
 import Control.Monad.Except (catchError, throwError)
-import Control.Monad.State (StateT, evalStateT, get, lift, modify)
-import Control.Monad.State (liftM)
+import Control.Monad.State.Strict (StateT, evalStateT, get, lift, modify)
+import Control.Monad.State.Strict (liftM)
 import Data.ByteString.Base64 (encode)
 import qualified Data.ByteString.Char8 as B8
 import Data.Char (isAscii, isControl, isSpace, toLower)

src/Text/Pandoc/Writers/HTML.hs

@@ -43,7 +43,7 @@ module Text.Pandoc.Writers.HTML (
   writeDZSlides,
   writeRevealJs
   ) where
-import Control.Monad.State
+import Control.Monad.State.Strict
 import Data.Char (ord, toLower)
 import Data.Text (Text)
 import qualified Data.Text.Lazy as TL

src/Text/Pandoc/Writers/Haddock.hs

@@ -33,7 +33,7 @@ Conversion of 'Pandoc' documents to haddock markup.
 Haddock:  <http://www.haskell.org/haddock/doc/html/>
 -}
 module Text.Pandoc.Writers.Haddock (writeHaddock) where
-import Control.Monad.State
+import Control.Monad.State.Strict
 import Data.Default
 import Data.Text (Text)
 import Data.List (intersperse, transpose)

src/Text/Pandoc/Writers/ICML.hs

@@ -17,7 +17,7 @@ into InDesign with File -> Place.
 -}
 module Text.Pandoc.Writers.ICML (writeICML) where
 import Control.Monad.Except (catchError)
-import Control.Monad.State
+import Control.Monad.State.Strict
 import Data.List (intersperse, isInfixOf, isPrefixOf, stripPrefix)
 import qualified Data.Set as Set
 import Data.Text as Text (breakOnAll, pack)

src/Text/Pandoc/Writers/LaTeX.hs

@@ -35,7 +35,7 @@ module Text.Pandoc.Writers.LaTeX (
   , writeBeamer
   ) where
 import Control.Applicative ((<|>))
-import Control.Monad.State
+import Control.Monad.State.Strict
 import Data.Aeson (FromJSON, object, (.=))
 import Data.Char (isAlphaNum, isAscii, isDigit, isLetter, isPunctuation, ord,
                   toLower)

src/Text/Pandoc/Writers/Man.hs

@@ -31,7 +31,7 @@ Conversion of 'Pandoc' documents to groff man page format.
 -}
 module Text.Pandoc.Writers.Man ( writeMan) where
 import Control.Monad.Except (throwError)
-import Control.Monad.State
+import Control.Monad.State.Strict
 import Data.List (intercalate, intersperse, stripPrefix, sort)
 import qualified Data.Map as Map
 import Data.Maybe (fromMaybe)

src/Text/Pandoc/Writers/Markdown.hs

@@ -35,7 +35,7 @@ Markdown:  <http://daringfireball.net/projects/markdown/>
 -}
 module Text.Pandoc.Writers.Markdown (writeMarkdown, writePlain) where
 import Control.Monad.Reader
-import Control.Monad.State
+import Control.Monad.State.Strict
 import Data.Char (chr, isPunctuation, isSpace, ord)
 import Data.Default
 import qualified Data.HashMap.Strict as H

src/Text/Pandoc/Writers/MediaWiki.hs

@@ -31,7 +31,7 @@ MediaWiki:  <http://www.mediawiki.org/wiki/MediaWiki>
 -}
 module Text.Pandoc.Writers.MediaWiki ( writeMediaWiki ) where
 import Control.Monad.Reader
-import Control.Monad.State
+import Control.Monad.State.Strict
 import Data.List (intercalate)
 import qualified Data.Set as Set
 import Data.Text (Text, pack)

src/Text/Pandoc/Writers/Ms.hs

@@ -52,7 +52,7 @@ import Text.Pandoc.Pretty
 import Text.Pandoc.Class (PandocMonad, report)
 import Text.Pandoc.ImageSize
 import Text.Pandoc.Logging
-import Control.Monad.State
+import Control.Monad.State.Strict
 import Data.Char ( isLower, isUpper, toUpper )
 import Text.TeXMath (writeEqn)
 import System.FilePath (takeExtension)

src/Text/Pandoc/Writers/Muse.hs

@@ -42,7 +42,7 @@ However, @\<literal style="html">@ tag is used for HTML raw blocks
 even though it is supported only in Emacs Muse.
 -}
 module Text.Pandoc.Writers.Muse (writeMuse) where
-import Control.Monad.State
+import Control.Monad.State.Strict
 import Data.Text (Text)
 import Data.List (intersperse, transpose, isInfixOf)
 import System.FilePath (takeExtension)

src/Text/Pandoc/Writers/ODT.hs

@@ -31,7 +31,7 @@ Conversion of 'Pandoc' documents to ODT.
 module Text.Pandoc.Writers.ODT ( writeODT ) where
 import Codec.Archive.Zip
 import Control.Monad.Except (catchError)
-import Control.Monad.State
+import Control.Monad.State.Strict
 import qualified Data.ByteString.Lazy as B
 import Data.List (isPrefixOf)
 import Data.Maybe (fromMaybe)

src/Text/Pandoc/Writers/OpenDocument.hs

@@ -33,7 +33,7 @@ Conversion of 'Pandoc' documents to OpenDocument XML.
 -}
 module Text.Pandoc.Writers.OpenDocument ( writeOpenDocument ) where
 import Control.Arrow ((***), (>>>))
-import Control.Monad.State hiding (when)
+import Control.Monad.State.Strict hiding (when)
 import Data.Char (chr)
 import Data.List (sortBy)
 import Data.Text (Text)

src/Text/Pandoc/Writers/Org.hs

@@ -35,7 +35,7 @@ Conversion of 'Pandoc' documents to Emacs Org-Mode.
 Org-Mode:  <http://orgmode.org>
 -}
 module Text.Pandoc.Writers.Org (writeOrg) where
-import Control.Monad.State
+import Control.Monad.State.Strict
 import Data.Char (isAlphaNum, toLower)
 import Data.Text (Text)
 import Data.List (intersect, intersperse, isPrefixOf, partition, transpose)

src/Text/Pandoc/Writers/RST.hs

@@ -31,7 +31,7 @@ Conversion of 'Pandoc' documents to reStructuredText.
 reStructuredText:  <http://docutils.sourceforge.net/rst.html>
 -}
 module Text.Pandoc.Writers.RST ( writeRST ) where
-import Control.Monad.State
+import Control.Monad.State.Strict
 import Data.Char (isSpace, toLower)
 import Data.List (isPrefixOf, stripPrefix)
 import Data.Maybe (fromMaybe)

src/Text/Pandoc/Writers/Texinfo.hs

@@ -32,7 +32,7 @@ Conversion of 'Pandoc' format into Texinfo.
 -}
 module Text.Pandoc.Writers.Texinfo ( writeTexinfo ) where
 import Control.Monad.Except (throwError)
-import Control.Monad.State
+import Control.Monad.State.Strict
 import Data.Char (chr, ord)
 import Data.List (maximumBy, transpose)
 import Data.Ord (comparing)

src/Text/Pandoc/Writers/Textile.hs

@@ -30,7 +30,7 @@ Conversion of 'Pandoc' documents to Textile markup.
 Textile:  <http://thresholdstate.com/articles/4312/the-textile-reference-manual>
 -}
 module Text.Pandoc.Writers.Textile ( writeTextile ) where
-import Control.Monad.State
+import Control.Monad.State.Strict
 import Data.Char (isSpace)
 import Data.List (intercalate)
 import Data.Text (Text, pack)

src/Text/Pandoc/Writers/ZimWiki.hs

@@ -33,7 +33,7 @@ http://zim-wiki.org/manual/Help/Wiki_Syntax.html
 
 module Text.Pandoc.Writers.ZimWiki ( writeZimWiki ) where
 import Control.Monad (zipWithM)
-import Control.Monad.State (StateT, evalStateT, gets, modify)
+import Control.Monad.State.Strict (StateT, evalStateT, gets, modify)
 import Data.Default (Default (..))
 import Data.List (intercalate, isInfixOf, isPrefixOf, transpose)
 import qualified Data.Map as Map