Added a plugin system, based on hint.

+ In Text.Pandoc.Definition, added processIn, processInM,
  and queryIn, and deprecated processPandoc and queryPandoc
  for these more general functions, which are useful in writing
  plugins.

+ Added module Text.Pandoc.Plugins.

+ Added a --plugins option to Main, and code to run the parsed pandoc
  document through all the plugins.

+ Provided five sample plugin files in the plugins/ directory.

+ Documented --plugin in the pandoc man page and README.


git-svn-id: https://pandoc.googlecode.com/svn/trunk@1519 788f1e2b-df1e-0410-8736-df70ead52e1b

1 files changed, 15 insertions, 0 deletions

diff --git a/plugins/ListLinksPlugin.hs b/plugins/ListLinksPlugin.hs
new file mode 100644
index 000000000..88c1553b1
--- /dev/null
+++ b/plugins/ListLinksPlugin.hs
@@ -0,0 +1,15 @@
+module ListLinksPlugin (transform) where
+import Text.Pandoc
+
+-- This plugin returns an empty document and prints a list
+-- of the URLs linked to in the source document.
+
+transform :: Pandoc -> IO Pandoc
+transform p = do
+  let urls = queryIn findURLs p
+  putStrLn $ unlines urls
+  return $ Pandoc (Meta [] [] []) []
+
+findURLs :: Inline -> [String]
+findURLs (Link label (url, title)) = [url]
+findURLs x                         = []