Added --ascii option.

Currently supported only in HTML writer.

4 files changed, 38 insertions, 19 deletions

diff --git a/README b/README
index 897d8b000..d14fd8938 100644
--- a/README
+++ b/README
@@ -292,6 +292,11 @@ Options
 `--columns`=*NUMBER*
 :   Specify length of lines in characters (for text wrapping).
 
+`--ascii`
+:   Use only ascii characters in output.  Currently supported only
+    for HTML output (which uses numerical entities instead of
+    UTF-8 when this option is selected).
+
 `--email-obfuscation=`*none|javascript|references*
 :   Specify a method for obfuscating `mailto:` links in HTML documents.
     *none* leaves `mailto:` links as they are.  *javascript* obfuscates
diff --git a/src/Text/Pandoc/Shared.hs b/src/Text/Pandoc/Shared.hs
index fec04a6c5..c4bc66830 100644
--- a/src/Text/Pandoc/Shared.hs
+++ b/src/Text/Pandoc/Shared.hs
@@ -490,6 +490,7 @@ data WriterOptions = WriterOptions
   , writerHtml5            :: Bool       -- ^ Produce HTML5
   , writerChapters         :: Bool       -- ^ Use "chapter" for top-level sects
   , writerListings         :: Bool       -- ^ Use listings package for code
+  , writerAscii            :: Bool       -- ^ Avoid non-ascii characters
   } deriving Show
 
 -- | Default writer options.
@@ -522,6 +523,7 @@ defaultWriterOptions =
                 , writerHtml5            = False
                 , writerChapters         = False
                 , writerListings         = False
+                , writerAscii            = False
                 }
 
 --
diff --git a/src/Text/Pandoc/Writers/HTML.hs b/src/Text/Pandoc/Writers/HTML.hs
index 1faeeea80..f9a10f355 100644
--- a/src/Text/Pandoc/Writers/HTML.hs
+++ b/src/Text/Pandoc/Writers/HTML.hs
@@ -43,6 +43,7 @@ import Data.List ( isPrefixOf, intersperse )
 import Data.Maybe ( catMaybes )
 import Control.Monad.State
 import Text.XHtml.Transitional hiding ( stringToHtml, unordList, ordList )
+import qualified Text.XHtml.Transitional as XHtml
 import Text.TeXMath
 import Text.XML.Light.Output
 
@@ -60,8 +61,10 @@ defaultWriterState = WriterState {stNotes= [], stMath = False, stHighlighting =
 
 -- | Modified version of Text.XHtml's stringToHtml.
 -- Use unicode characters wherever possible.
-stringToHtml :: String -> Html
-stringToHtml = primHtml . escapeStringForXML
+stringToHtml :: WriterOptions -> String -> Html
+stringToHtml opts = if writerAscii opts
+                       then XHtml.stringToHtml
+                       else primHtml . escapeStringForXML
 
 -- | Hard linebreak.
 nl :: WriterOptions -> Html
@@ -219,7 +222,7 @@ elementToListItem _ (Blk _) = return Nothing
 elementToListItem opts (Sec _ num id' headerText subsecs) = do
   let sectnum = if writerNumberSections opts
                    then (thespan ! [theclass "toc-section-number"] << showSecNum num) +++
-                         stringToHtml " "
+                         stringToHtml opts" "
                    else noHtml
   txt <- liftM (sectnum +++) $ inlineListToHtml opts headerText
   subHeads <- mapM (elementToListItem opts) subsecs >>= return . catMaybes
@@ -301,7 +304,7 @@ obfuscateLink opts txt s =
                      linkText  ++ "+'<\\/'+'a'+'>');\n// -->\n")) +++  
                      noscript (primHtml $ obfuscateString altText)
                 _ -> error $ "Unknown obfuscation method: " ++ show meth
-        _ -> anchor ! [href s] $ stringToHtml txt  -- malformed email
+        _ -> anchor ! [href s] $ stringToHtml opts txt  -- malformed email
 
 -- | Obfuscate character as entity.
 obfuscateChar :: Char -> String
@@ -353,7 +356,7 @@ blockToHtml opts (CodeBlock (id',classes,keyvals) rawCode) = do
                                      else unlines . lines
                     in  return $ pre ! attrs $ thecode <<
                                  (replicate (length leadingBreaks) br +++
-                                 [stringToHtml $ addBird rawCode'])
+                                 [stringToHtml opts $ addBird rawCode'])
          Right h -> modify (\st -> st{ stHighlighting = True }) >>
                     return h
 blockToHtml opts (BlockQuote blocks) =
@@ -379,7 +382,7 @@ blockToHtml opts (Header level lst) = do
   secnum <- liftM stSecNum get
   let contents' = if writerNumberSections opts
                      then (thespan ! [theclass "header-section-number"] << showSecNum secnum) +++
-                            stringToHtml " " +++ contents
+                            stringToHtml opts " " +++ contents
                      else contents
   let contents''  = if writerTableOfContents opts
                        then anchor ! [href $ "#" ++ writerIdentifierPrefix opts ++ "TOC"] $ contents'
@@ -512,19 +515,19 @@ inlineListToHtml opts lst =
 inlineToHtml :: WriterOptions -> Inline -> State WriterState Html
 inlineToHtml opts inline =
   case inline of  
-    (Str str)        -> return $ stringToHtml str
-    (Space)          -> return $ stringToHtml " "
+    (Str str)        -> return $ stringToHtml opts str
+    (Space)          -> return $ stringToHtml opts " "
     (LineBreak)      -> return br
-    (EmDash)         -> return $ stringToHtml "—"
-    (EnDash)         -> return $ stringToHtml "–"
-    (Ellipses)       -> return $ stringToHtml "…"
-    (Apostrophe)     -> return $ stringToHtml "’"
+    (EmDash)         -> return $ stringToHtml opts "—"
+    (EnDash)         -> return $ stringToHtml opts "–"
+    (Ellipses)       -> return $ stringToHtml opts "…"
+    (Apostrophe)     -> return $ stringToHtml opts "’"
     (Emph lst)       -> inlineListToHtml opts lst >>= return . emphasize
     (Strong lst)     -> inlineListToHtml opts lst >>= return . strong
     (Code attr str)  -> case highlightHtml True attr str of
                              Left _  -> return
                                         $ thecode ! (attrsToHtml opts attr)
-                                        $ stringToHtml str
+                                        $ stringToHtml opts str
                              Right h -> return h
     (Strikeout lst)  -> inlineListToHtml opts lst >>=
                         return . (thespan ! [thestyle "text-decoration: line-through;"])
@@ -534,10 +537,10 @@ inlineToHtml opts inline =
     (Subscript lst)   -> inlineListToHtml opts lst >>= return . sub
     (Quoted quoteType lst) ->
                         let (leftQuote, rightQuote) = case quoteType of
-                              SingleQuote -> (stringToHtml "‘",
-                                              stringToHtml "’")
-                              DoubleQuote -> (stringToHtml "“",
-                                              stringToHtml "”")
+                              SingleQuote -> (stringToHtml opts "‘",
+                                              stringToHtml opts "’")
+                              DoubleQuote -> (stringToHtml opts "“",
+                                              stringToHtml opts "”")
                         in  do contents <- inlineListToHtml opts lst
                                return $ leftQuote +++ contents +++ rightQuote
     (Math t str) ->     modify (\st -> st {stMath = True}) >> 
diff --git a/src/pandoc.hs b/src/pandoc.hs
index c0f457449..e73f05965 100644
--- a/src/pandoc.hs
+++ b/src/pandoc.hs
@@ -123,6 +123,7 @@ data Opt = Opt
     , optBibliography      :: [String]
     , optCslFile           :: FilePath
     , optListings          :: Bool       -- ^ Use listings package for code blocks
+    , optAscii             :: Bool       -- ^ Avoid using nonascii characters
     }
 
 -- | Defaults for command-line options.
@@ -166,6 +167,7 @@ defaultOpts = Opt
     , optBibliography      = []
     , optCslFile           = ""
     , optListings          = False
+    , optAscii             = False
     }
 
 -- | A list of functions, each transforming the options data structure
@@ -347,6 +349,11 @@ options =
                  "NUMBER")
                  "" -- "Length of line in characters"
 
+    , Option "" ["ascii"]
+                 (NoArg
+                  (\opt -> return opt { optAscii = True }))
+                 "" -- "Avoid using non-ascii characters in output"
+
     , Option "" ["email-obfuscation"]
                  (ReqArg
                   (\arg opt -> do
@@ -681,7 +688,8 @@ main = do
               , optBibliography      = reffiles
               , optCslFile           = cslfile
               , optCiteMethod        = citeMethod
-              , optListings          = listings 
+              , optListings          = listings
+              , optAscii             = ascii
              } = opts
 
   when dumpArgs $
@@ -803,7 +811,8 @@ main = do
                                       writerHtml5            = html5 &&
                                                                "html" `isPrefixOf` writerName',
                                       writerChapters         = chapters, 
-                                      writerListings         = listings }
+                                      writerListings         = listings,
+                                      writerAscii            = ascii }
 
   when (isNonTextOutput writerName' && outputFile == "-") $
     do UTF8.hPutStrLn stderr ("Error:  Cannot write " ++ writerName ++ " output to stdout.\n" ++