Citation related changes.

* Don't look for bibliography in ~/.pandoc.  Reason:  doing
  this requires a read + parse of the bibliography even when
  the document doesn't use citations.  This is a big performance
  drag on regular pandoc invocations.
* Only look for default.csl if the document contains references.
  Reason:  avoids the need to read and parse csl file when the
  document contains no references anyway.
* Removed findFirstFile from Shared.

src/Text/Pandoc/Biblio.hs

@@ -38,10 +38,11 @@ import Text.Pandoc.Definition
 
 -- | Process a 'Pandoc' document by adding citations formatted
 -- according to a CSL style, using 'citeproc' from citeproc-hs.
-processBiblio :: Style -> [Reference] -> Pandoc -> IO Pandoc
-processBiblio csl r p
+processBiblio :: FilePath -> [Reference] -> Pandoc -> IO Pandoc
+processBiblio cslfile r p
     = if null r then return p
       else do
+        csl <- readCSLFile cslfile
         p'   <- processWithM setHash p
         let (nts,grps) = if styleClass csl /= "note"
                          then (,) [] $ queryWith getCitation p'

src/Text/Pandoc/Shared.hs

@@ -71,7 +71,6 @@ module Text.Pandoc.Shared (
                      defaultWriterOptions,
                      -- * File handling
                      inDirectory,
-                     findFirstFile,
                      findDataFile,
                      readDataFile
                     ) where
@@ -540,17 +539,6 @@ inDirectory path action = do
   setCurrentDirectory oldDir
   return result
 
--- | Get full file path for the first of a list of files found in the
--- specified directory.
-findFirstFile :: (Maybe FilePath) -> [FilePath] -> IO (Maybe FilePath)
-findFirstFile Nothing _     = return Nothing
-findFirstFile (Just _) []   = return Nothing
-findFirstFile (Just dir) (f:fs) = do
-  ex <- doesFileExist (dir </> f)
-  if ex
-     then return $ Just (dir </> f)
-     else findFirstFile (Just dir) fs
-
 -- | Get file path for data file, either from specified user data directory,
 -- or, if not found there, from Cabal data directory.
 findDataFile :: Maybe FilePath -> FilePath -> IO FilePath

src/pandoc.hs

@@ -32,7 +32,7 @@ module Main where
 import Text.Pandoc
 import Text.Pandoc.S5 (s5HeaderIncludes)
 import Text.Pandoc.Shared ( tabFilter, ObfuscationMethod (..), readDataFile,
-                            headerShift, findDataFile, findFirstFile )
+                            headerShift, findDataFile )
 #ifdef _HIGHLIGHTING
 import Text.Pandoc.Highlighting ( languages )
 #endif
@@ -767,25 +767,6 @@ main = do
                          return $ ("mathml-script", s) : variables'
                       _ -> return variables'
 
-#ifdef _CITEPROC
-  cslfile' <- if null cslfile
-                 then findDataFile datadir "default.csl"
-                 else return cslfile
-  csl <- readCSLFile cslfile'
-  refs' <- if null refs
-              then do
-                f <- findFirstFile datadir
-                       ["biblio.xml","biblio.json","biblio.bib"]
-                case f of
-                     Just x  -> catch (readBiblioFile x) $ \e -> do
-                                 UTF8.hPutStrLn stderr $
-                                  "Error reading bibliography `" ++ x ++ "'"
-                                 UTF8.hPutStrLn stderr $ show e
-                                 exitWith (ExitFailure 23) >> return []
-                     Nothing -> return []
-              else return refs
-#endif
-
   let sourceDir = if null sources
                      then "."
                      else takeDirectory (head sources)
@@ -803,7 +784,7 @@ main = do
                                                      lhsExtension sources,
                               stateStandalone      = standalone',
 #ifdef _CITEPROC
-                              stateCitations       = map refId refs',
+                              stateCitations       = map refId refs,
 #endif
                               stateSmart           = smart || writerName' `elem`
                                                               ["latex", "context", "latex+lhs", "man"],
@@ -863,7 +844,13 @@ main = do
 
   doc'' <- do
 #ifdef _CITEPROC
-          processBiblio csl refs' doc'
+          if null refs
+             then return doc'
+             else do
+                cslfile' <- if null cslfile
+                               then findDataFile datadir "default.csl"
+                               else return cslfile
+                processBiblio cslfile' refs doc'
 #else
           return doc'
 #endif