Move some code from T.P.R.LaTeX. to T.P.R.LaTeX.Parsing.

We need to reduce the size of the LaTeX reader to ease
compilation on resource-limited systems.  More can be done
in this vein.

src/Text/Pandoc/Readers/LaTeX.hs

@@ -586,44 +586,6 @@ nlToSpace :: Char -> Char
 nlToSpace '\n' = ' '
 nlToSpace x    = x
 
-keyval :: PandocMonad m => LP m (Text, Text)
-keyval = try $ do
-  Tok _ Word key <- satisfyTok isWordTok
-  sp
-  val <- option mempty $ do
-           symbol '='
-           sp
-           (untokenize <$> braced) <|>
-             (mconcat <$> many1 (
-                 (untokenize . snd <$> withRaw braced)
-                 <|>
-                 (untokenize <$> (many1
-                      (satisfyTok
-                         (\t -> case t of
-                                Tok _ Symbol "]" -> False
-                                Tok _ Symbol "," -> False
-                                Tok _ Symbol "{" -> False
-                                Tok _ Symbol "}" -> False
-                                _                -> True))))))
-  optional (symbol ',')
-  sp
-  return (key, T.strip val)
-
-keyvals :: PandocMonad m => LP m [(Text, Text)]
-keyvals = try $ symbol '[' >> manyTill keyval (symbol ']') <* sp
-
-accent :: PandocMonad m => Char -> Maybe Char -> LP m Inlines
-accent combiningAccent fallBack = try $ do
-  ils <- tok
-  case toList ils of
-       (Str (T.uncons -> Just (x, xs)) : ys) -> return $ fromList $
-         -- try to normalize to the combined character:
-         Str (Normalize.normalize Normalize.NFC
-               (T.pack [x, combiningAccent]) <> xs) : ys
-       [Space]           -> return $ str $ T.singleton $ fromMaybe combiningAccent fallBack
-       []                -> return $ str $ T.singleton $ fromMaybe combiningAccent fallBack
-       _                 -> return ils
-
 mathDisplay :: Text -> Inlines
 mathDisplay = displayMath . trimMath
 
@@ -782,6 +744,7 @@ inlineCommand' = try $ do
          <|> ignore rawcommand
   lookupListDefault raw names inlineCommands
 
+
 tok :: PandocMonad m => LP m Inlines
 tok = try $ spaces >> grouped inline <|> inlineCommand' <|> singleChar'
   where singleChar' = do
@@ -1178,6 +1141,19 @@ inlineCommands = M.union inlineLanguageCommands $ M.fromList
   , ("ifdim", ifdim)
   ]
 
+accent :: PandocMonad m => Char -> Maybe Char -> LP m Inlines
+accent combiningAccent fallBack = try $ do
+  ils <- tok
+  case toList ils of
+       (Str (T.uncons -> Just (x, xs)) : ys) -> return $ fromList $
+         -- try to normalize to the combined character:
+         Str (Normalize.normalize Normalize.NFC
+               (T.pack [x, combiningAccent]) <> xs) : ys
+       [Space]           -> return $ str $ T.singleton $ fromMaybe combiningAccent fallBack
+       []                -> return $ str $ T.singleton $ fromMaybe combiningAccent fallBack
+       _                 -> return ils
+
+
 lettrine :: PandocMonad m => LP m Inlines
 lettrine = do
   optional opt
@@ -1471,20 +1447,6 @@ inlines = mconcat <$> many inline
 
 -- block elements:
 
-begin_ :: PandocMonad m => Text -> LP m ()
-begin_ t = try (do
-  controlSeq "begin"
-  spaces
-  txt <- untokenize <$> braced
-  guard (t == txt)) <?> ("\\begin{" ++ T.unpack t ++ "}")
-
-end_ :: PandocMonad m => Text -> LP m ()
-end_ t = try (do
-  controlSeq "end"
-  spaces
-  txt <- untokenize <$> braced
-  guard $ t == txt) <?> ("\\end{" ++ T.unpack t ++ "}")
-
 preamble :: PandocMonad m => LP m Blocks
 preamble = mconcat <$> many preambleBlock
   where preambleBlock =  (mempty <$ spaces1)
@@ -1997,24 +1959,6 @@ rawVerbEnv name = do
        report $ SkippedContent raw' pos
        return mempty
 
-verbEnv :: PandocMonad m => Text -> LP m Text
-verbEnv name = withVerbatimMode $ do
-  optional blankline
-  res <- manyTill anyTok (end_ name)
-  return $ stripTrailingNewline
-         $ untokenize
-         $ res
-
--- Strip single final newline and any spaces following it.
--- Input is unchanged if it doesn't end with newline +
--- optional spaces.
-stripTrailingNewline :: Text -> Text
-stripTrailingNewline t =
-  let (b, e) = T.breakOnEnd "\n" t
-  in  if T.all (== ' ') e
-         then T.dropEnd 1 b
-         else t
-
 fancyverbEnv :: PandocMonad m => Text -> LP m Blocks
 fancyverbEnv name = do
   options <- option [] keyvals

src/Text/Pandoc/Readers/LaTeX/Parsing.hs

@@ -2,6 +2,7 @@
 {-# LANGUAGE MultiParamTypeClasses #-}
 {-# LANGUAGE OverloadedStrings     #-}
 {-# LANGUAGE ScopedTypeVariables   #-}
+{-# LANGUAGE ViewPatterns          #-}
 {- |
    Module      : Text.Pandoc.Readers.LaTeX.Parsing
    Copyright   : Copyright (C) 2006-2020 John MacFarlane
@@ -66,6 +67,10 @@ module Text.Pandoc.Readers.LaTeX.Parsing
   , dimenarg
   , ignore
   , withRaw
+  , keyvals
+  , verbEnv
+  , begin_
+  , end_
   ) where
 
 import Control.Applicative (many, (<|>))
@@ -695,3 +700,62 @@ withRaw parser = do
   let raw = takeWhile (\(Tok pos _ _) -> maybe True
                   (\p -> sourceName p /= sourceName pos || pos < p) nxtpos) inp
   return (result, raw)
+
+keyval :: PandocMonad m => LP m (Text, Text)
+keyval = try $ do
+  Tok _ Word key <- satisfyTok isWordTok
+  sp
+  val <- option mempty $ do
+           symbol '='
+           sp
+           (untokenize <$> braced) <|>
+             (mconcat <$> many1 (
+                 (untokenize . snd <$> withRaw braced)
+                 <|>
+                 (untokenize <$> (many1
+                      (satisfyTok
+                         (\t -> case t of
+                                Tok _ Symbol "]" -> False
+                                Tok _ Symbol "," -> False
+                                Tok _ Symbol "{" -> False
+                                Tok _ Symbol "}" -> False
+                                _                -> True))))))
+  optional (symbol ',')
+  sp
+  return (key, T.strip val)
+
+keyvals :: PandocMonad m => LP m [(Text, Text)]
+keyvals = try $ symbol '[' >> manyTill keyval (symbol ']') <* sp
+
+verbEnv :: PandocMonad m => Text -> LP m Text
+verbEnv name = withVerbatimMode $ do
+  optional blankline
+  res <- manyTill anyTok (end_ name)
+  return $ stripTrailingNewline
+         $ untokenize
+         $ res
+
+-- Strip single final newline and any spaces following it.
+-- Input is unchanged if it doesn't end with newline +
+-- optional spaces.
+stripTrailingNewline :: Text -> Text
+stripTrailingNewline t =
+  let (b, e) = T.breakOnEnd "\n" t
+  in  if T.all (== ' ') e
+         then T.dropEnd 1 b
+         else t
+
+begin_ :: PandocMonad m => Text -> LP m ()
+begin_ t = try (do
+  controlSeq "begin"
+  spaces
+  txt <- untokenize <$> braced
+  guard (t == txt)) <?> ("\\begin{" ++ T.unpack t ++ "}")
+
+end_ :: PandocMonad m => Text -> LP m ()
+end_ t = try (do
+  controlSeq "end"
+  spaces
+  txt <- untokenize <$> braced
+  guard $ t == txt) <?> ("\\end{" ++ T.unpack t ++ "}")
+