Opt: Change optHighlightStyle to a Maybe String instead of Maybe Style.

Do the parsing/loading of themes later, after option parsing.

3 files changed, 28 insertions, 24 deletions

diff --git a/src/Text/Pandoc/App/CommandLineOptions.hs b/src/Text/Pandoc/App/CommandLineOptions.hs
index adf1d3715..960d7cb5f 100644
--- a/src/Text/Pandoc/App/CommandLineOptions.hs
+++ b/src/Text/Pandoc/App/CommandLineOptions.hs
@@ -20,10 +20,12 @@ module Text.Pandoc.App.CommandLineOptions (
             parseOptions
           , options
           , engines
+          , lookupHighlightStyle
           ) where
 import Prelude
 import Control.Monad
 import Control.Monad.Trans
+import Control.Monad.Except (throwError)
 import Data.Aeson.Encode.Pretty (encodePretty', Config(..), keyOrder,
          defConfig, Indent(..), NumberFormat(..))
 import Data.Char (toLower)
@@ -34,8 +36,7 @@ import Data.List (isPrefixOf)
 #endif
 #endif
 import Data.Maybe (fromMaybe)
-import Skylighting (Style, Syntax (..), defaultSyntaxMap, parseTheme,
-                    pygments)
+import Skylighting (Style, Syntax (..), defaultSyntaxMap, parseTheme)
 import System.Console.GetOpt
 import System.Environment (getArgs, getProgName)
 import System.Exit (exitSuccess)
@@ -47,6 +48,7 @@ import Text.Pandoc.Filter (Filter (..))
 import Text.Pandoc.Highlighting (highlightingStyles)
 import Text.Pandoc.Writers.Math (defaultMathJaxURL, defaultKaTeXURL)
 import Text.Pandoc.Shared (ordNub, safeRead, defaultUserDataDirs)
+import Text.Pandoc.Class (PandocMonad(..), runIOorExplode)
 import Text.Printf
 
 #ifdef EMBED_DATA_FILES
@@ -102,20 +104,6 @@ engines = map ("html",) htmlEngines ++
 pdfEngines :: [String]
 pdfEngines = ordNub $ map snd engines
 
-lookupHighlightStyle :: String -> IO (Maybe Style)
-lookupHighlightStyle s
-  | takeExtension s == ".theme" = -- attempt to load KDE theme
-    do contents <- B.readFile s
-       case parseTheme contents of
-            Left _    -> E.throwIO $ PandocOptionError $
-                           "Could not read highlighting theme " ++ s
-            Right sty -> return (Just sty)
-  | otherwise =
-  case lookup (map toLower s) highlightingStyles of
-       Just sty -> return (Just sty)
-       Nothing  -> E.throwIO $ PandocOptionError $
-                      "Unknown highlight-style " ++ s
-
 -- | A list of functions, each transforming the options data structure
 --   in response to a command-line option.
 options :: [OptDescr (Opt -> IO Opt)]
@@ -296,8 +284,8 @@ options =
 
     , Option "" ["highlight-style"]
                 (ReqArg
-                 (\arg opt -> lookupHighlightStyle arg >>= \style ->
-                     return opt{ optHighlightStyle = style })
+                 (\arg opt ->
+                     return opt{ optHighlightStyle = Just arg })
                  "STYLE|FILE")
                  "" -- "Style for highlighted code"
 
@@ -856,7 +844,7 @@ options =
                      let write = case optOutputFile opt of
                                         Just f  -> B.writeFile f
                                         Nothing -> B.putStr
-                     sty <- fromMaybe pygments <$> lookupHighlightStyle arg
+                     sty <- runIOorExplode $ lookupHighlightStyle arg
                      write $ encodePretty'
                        defConfig{confIndent = Spaces 4
                                 ,confCompare = keyOrder
@@ -965,6 +953,20 @@ splitField s =
        (k,_:v) -> (k,v)
        (k,[])  -> (k,"true")
 
+lookupHighlightStyle :: PandocMonad m => String -> m Style
+lookupHighlightStyle s
+  | takeExtension s == ".theme" = -- attempt to load KDE theme
+    do contents <- readFileLazy s
+       case parseTheme contents of
+            Left _    -> throwError $ PandocOptionError $
+                           "Could not read highlighting theme " ++ s
+            Right sty -> return sty
+  | otherwise =
+  case lookup (map toLower s) highlightingStyles of
+       Just sty -> return sty
+       Nothing  -> throwError $ PandocOptionError $
+                      "Unknown highlight-style " ++ s
+
 deprecatedOption :: String -> String -> IO ()
 deprecatedOption o msg =
   runIO (report $ Deprecated o msg) >>=
diff --git a/src/Text/Pandoc/App/Opt.hs b/src/Text/Pandoc/App/Opt.hs
index 126f5db4c..3fe7cadf1 100644
--- a/src/Text/Pandoc/App/Opt.hs
+++ b/src/Text/Pandoc/App/Opt.hs
@@ -23,7 +23,6 @@ module Text.Pandoc.App.Opt (
 import Prelude
 import GHC.Generics
 import Text.Pandoc.Filter (Filter (..))
-import Text.Pandoc.Highlighting (Style, pygments)
 import Text.Pandoc.Logging (Verbosity (WARNING))
 import Text.Pandoc.Options (TopLevelDivision (TopLevelDefault),
                             TrackChanges (AcceptChanges),
@@ -63,7 +62,7 @@ data Opt = Opt
     , optIncremental           :: Bool    -- ^ Use incremental lists in Slidy/Slideous/S5
     , optSelfContained         :: Bool    -- ^ Make HTML accessible offline
     , optHtmlQTags             :: Bool    -- ^ Use <q> tags in HTML
-    , optHighlightStyle        :: Maybe Style -- ^ Style to use for highlighted code
+    , optHighlightStyle        :: Maybe String -- ^ Style to use for highlighted code
     , optSyntaxDefinitions     :: [FilePath]  -- ^ xml syntax defs to load
     , optTopLevelDivision      :: TopLevelDivision -- ^ Type of the top-level divisions
     , optHTMLMathMethod        :: HTMLMathMethod -- ^ Method to print HTML math
@@ -137,7 +136,7 @@ defaultOpts = Opt
     , optIncremental           = False
     , optSelfContained         = False
     , optHtmlQTags             = False
-    , optHighlightStyle        = Just pygments
+    , optHighlightStyle        = Just "pygments"
     , optSyntaxDefinitions     = []
     , optTopLevelDivision      = TopLevelDefault
     , optHTMLMathMethod        = PlainMath
diff --git a/src/Text/Pandoc/App/OutputSettings.hs b/src/Text/Pandoc/App/OutputSettings.hs
index cfb6f7ec2..04ea89eda 100644
--- a/src/Text/Pandoc/App/OutputSettings.hs
+++ b/src/Text/Pandoc/App/OutputSettings.hs
@@ -35,7 +35,7 @@ import System.IO (stdout)
 import Text.Pandoc
 import Text.Pandoc.App.FormatHeuristics (formatFromFilePaths)
 import Text.Pandoc.App.Opt (Opt (..))
-import Text.Pandoc.App.CommandLineOptions (engines)
+import Text.Pandoc.App.CommandLineOptions (engines, lookupHighlightStyle)
 import Text.Pandoc.BCP47 (Lang (..), parseBCP47)
 import qualified Text.Pandoc.UTF8 as UTF8
 
@@ -105,6 +105,9 @@ optToOutputSettings opts = do
   syntaxMap <- foldM addSyntaxMap defaultSyntaxMap
                      (optSyntaxDefinitions opts)
 
+  hlStyle <- maybe (return Nothing) (fmap Just . lookupHighlightStyle)
+                (optHighlightStyle opts)
+
   -- note: this reverses the list constructed in option parsing,
   -- which in turn was reversed from the command-line order,
   -- so we end up with the correct order in the variable list:
@@ -221,7 +224,7 @@ optToOutputSettings opts = do
         , writerTopLevelDivision = optTopLevelDivision opts
         , writerListings         = optListings opts
         , writerSlideLevel       = optSlideLevel opts
-        , writerHighlightStyle   = optHighlightStyle opts
+        , writerHighlightStyle   = hlStyle
         , writerSetextHeaders    = optSetextHeaders opts
         , writerEpubSubdirectory = optEpubSubdirectory opts
         , writerEpubMetadata     = epubMetadata