LaTeX reader: handle otherlanguage environment...

...and language-name environments like
`\begin{french}...\end{french}`.
Closes #9202.

src/Text/Pandoc/Readers/LaTeX.hs

@@ -61,7 +61,8 @@ import Text.Pandoc.Readers.LaTeX.Table (tableEnvironments)
 import Text.Pandoc.Readers.LaTeX.Macro (macroDef)
 import Text.Pandoc.Readers.LaTeX.Lang (inlineLanguageCommands,
                                        enquoteCommands,
-                                       babelLangToBCP47, setDefaultLanguage)
+                                       babelLangToBCP47,
+                                       setDefaultLanguage)
 import Text.Pandoc.Readers.LaTeX.SIunitx (siunitxCommands)
 import Text.Pandoc.Readers.LaTeX.Inline (acronymCommands, refCommands,
                                          nameCommands, charCommands,
@@ -1045,8 +1046,24 @@ environments = M.union (tableEnvironments blocks inline) $
    , ("togglefalse", braced >>= setToggle False)
    , ("iftoggle", try $ ifToggle >> block)
    , ("CSLReferences", braced >> braced >> env "CSLReferences" blocks)
+   , ("otherlanguage", env "otherlanguage" otherlanguageEnv)
    ]
 
+otherlanguageEnv :: PandocMonad m => LP m Blocks
+otherlanguageEnv = do
+  skipopts
+  babelLang <- untokenize <$> braced
+  case babelLangToBCP47 babelLang of
+    Just lang -> divWith ("", [], [("lang", renderLang lang)]) <$> blocks
+    Nothing -> blocks
+
+langEnvironment :: PandocMonad m => Text -> LP m Blocks
+langEnvironment name =
+  case babelLangToBCP47 name of
+    Just lang ->
+      env name (divWith ("", [], [("lang", renderLang lang)]) <$> blocks)
+    Nothing -> mzero -- fall through to raw environment
+
 filecontents :: PandocMonad m => LP m Blocks
 filecontents = try $ do
   controlSeq "begin"
@@ -1064,6 +1081,7 @@ environment = try $ do
   controlSeq "begin"
   name <- untokenize <$> braced
   M.findWithDefault mzero name environments <|>
+    langEnvironment name <|>
     theoremEnvironment blocks opt name <|>
     if M.member name (inlineEnvironments
                        :: M.Map Text (LP PandocPure Inlines))

test/command/9202.md

@@ -0,0 +1,62 @@
+```
+% pandoc -f latex -t native
+\begin{otherlanguage}{french}
+Bonjour.
+\end{otherlanguage}
+^D
+[ Div
+    ( "" , [] , [ ( "lang" , "fr" ) ] )
+    [ Para [ Str "Bonjour." ] ]
+]
+```
+
+```
+% pandoc -f latex -t native
+\begin{otherlanguage*}{french}
+Bonjour.
+\end{otherlanguage*}
+^D
+[ Div
+    ( "" , [ "otherlanguage*" ] , [] )
+    [ Para
+        [ Span ( "" , [] , [] ) [ Str "french" ]
+        , SoftBreak
+        , Str "Bonjour."
+        ]
+    ]
+]
+```
+
+```
+% pandoc -f latex -t native
+\textfrench{Bonjour}
+^D
+[ Para
+    [ Span ( "" , [] , [ ( "lang" , "fr" ) ] ) [ Str "Bonjour" ]
+    ]
+]
+```
+
+```
+% pandoc -f latex -t native
+\foreignlanguage{swissgerman}{Guten tag}
+^D
+[ Para
+    [ Span
+        ( "" , [] , [ ( "lang" , "de-CH-1901" ) ] )
+        [ Str "Guten" , Space , Str "tag" ]
+    ]
+]
+```
+
+```
+% pandoc -f latex -t native
+\begin{french}
+Bonjour.
+\end{french}
+^D
+[ Div
+    ( "" , [] , [ ( "lang" , "fr" ) ] )
+    [ Para [ Str "Bonjour." ] ]
+]
+```