Added pandoc filter to parse links in vimwiki

.config/vimwiki/README.md

@@ -0,0 +1,6 @@
+# How to compile the filter
+
+In order to compile the filter you must type: `ghc -static --make filter.hs`. Keep in mind that you don't need to compile anything, because you can just make the `filter.hs` file executable via `chmod +x filter.hs` and then run it via: 
+`pandoc -f markdown -t html --filter ./filter.hs -o index.html index.md`.
+
+To do that remember also to add the shebang: `#!/usr/bin/env runhaskell`

.config/vimwiki/delink.hs

@@ -0,0 +1,10 @@
+#!/usr/bin/env runhaskell
+-- This haskell filter removes links from the document
+
+import Text.Pandoc.JSON
+
+main = toJSONFilter delink
+
+delink :: Inline -> [Inline]
+delink (Link _ txt _) = txt
+delink x              = [x]

.config/vimwiki/linkParser.hs

@@ -0,0 +1,18 @@
+#!/usr/bin/env runhaskell
+-- This simple filter checks if the link contained is a valid url, if it isn't
+-- it adds a .html extenstion to the link (it's supposed to be a page in the wiki)
+
+import Text.Pandoc.JSON
+import Text.Regex.TDFA ((=~))
+import Data.Text (pack, unpack)
+
+main = toJSONFilter linkParser
+
+linkParser :: Inline -> Inline
+linkParser (Link attr txt (url, title)) = Link attr txt (newUrl, title)
+  where
+    newUrl = if isValidURL (unpack url) then url else pack (unpack url ++ ".html")
+linkParser x              = x
+
+isValidURL :: String -> Bool
+isValidURL url = url =~ ("^((https?|ftp)://)*[a-zA-Z0-9]+(\\.[a-zA-Z0-9]+)+([/?].*)?$" :: String)