Added build option for syntax highlighting, with *optional* dependency on highlighting-kate.

+ pandoc.cabal includes a flag, 'highlighting', that causes a dependency
  on highlighting-kate.
+ if Setup.hs detects this dependency, it copies templates/Highlighting.yes.hs
  to Text/Pandoc/Highlighting.hs.  Otherwise, it copies templates/Highlighting.no.hs.
+ The HTML writer imports this new module instead of Text.Highlighting.Kate.
  The new module exports highlightHtml, which either uses highlighting-kate to
  perform syntax highlighting or automatically returns a failure code, depending
  on whether highlighting support was selected.
+ --version now prints information about whether syntax highlighting support is compiled in.


git-svn-id: https://pandoc.googlecode.com/svn/trunk@1221 788f1e2b-df1e-0410-8736-df70ead52e1b

2 files changed, 87 insertions, 0 deletions

diff --git a/templates/Highlighting.no.hs b/templates/Highlighting.no.hs
new file mode 100644
index 000000000..2acea4420
--- /dev/null
+++ b/templates/Highlighting.no.hs
@@ -0,0 +1,39 @@
+{-
+Copyright (C) 2008 John MacFarlane <jgm@berkeley.edu>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+-}
+
+{- |
+   Module      : Text.Pandoc.Highlighting
+   Copyright   : Copyright (C) 2008 John MacFarlane
+   License     : GNU GPL, version 2 or above 
+
+   Maintainer  : John MacFarlane <jgm@berkeley.edu>
+   Stability   : alpha
+   Portability : portable
+
+Exports functions for syntax highlighting.
+-}
+
+module Text.Pandoc.Highlighting ( languages, highlightHtml ) where
+import Text.XHtml
+
+languages :: [String]
+languages = []
+
+highlightHtml :: [String] -> String -> Either String Html
+highlightHtml classes str = Left "Pandoc was not compiled with support for highlighting"
+
diff --git a/templates/Highlighting.yes.hs b/templates/Highlighting.yes.hs
new file mode 100644
index 000000000..a015e1e34
--- /dev/null
+++ b/templates/Highlighting.yes.hs
@@ -0,0 +1,48 @@
+{-
+Copyright (C) 2008 John MacFarlane <jgm@berkeley.edu>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+-}
+
+{- |
+   Module      : Text.Pandoc.Highlighting
+   Copyright   : Copyright (C) 2008 John MacFarlane
+   License     : GNU GPL, version 2 or above 
+
+   Maintainer  : John MacFarlane <jgm@berkeley.edu>
+   Stability   : alpha
+   Portability : portable
+
+Exports functions for syntax highlighting.
+-}
+
+module Text.Pandoc.Highlighting ( languages, highlightHtml ) where
+import Text.Highlighting.Kate
+import Text.XHtml
+import Data.List (find)
+import Data.Char (toLower)
+
+highlightHtml :: [String] -> String -> Either String Html
+highlightHtml classes rawCode =
+  let fmtOpts = case find (`elem` ["number","numberLines","number-lines"]) classes of
+                  Nothing   -> []
+                  Just _    -> [OptNumberLines]
+      lcLanguages = map (map toLower) languages
+  in  case find (\c -> (map toLower c) `elem` lcLanguages) classes of
+            Nothing   -> Left "Unknown or unsupported language"
+            Just lang -> case highlightAs lang rawCode of
+                               Left err -> Left err
+                               Right hl -> Right $ formatAsXHtml fmtOpts lang hl
+