1 files changed, 48 insertions, 0 deletions
diff --git a/src/lib/haskell/Parser/Utils.hs b/src/lib/haskell/Parser/Utils.hs
new file mode 100644
index 0000000..4768327
--- /dev/null
+++ b/src/lib/haskell/Parser/Utils.hs
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+module Parser.Utils
+  ( getTagsBefore
+  , getTagsAfter
+  , getTagsBetween
+  , getTagAttributes
+  , getTagAttribute
+  , getTagTextAfter
+  ) where
+
+import           Data.List         (find, findIndex)
+import           Data.Maybe        (catMaybes, listToMaybe)
+import           Data.Text         (Text)
+import qualified Data.Text         as T
+import           Text.HTML.TagSoup
+
+getTagsBefore :: Text -> [Tag Text] -> [Tag Text]
+getTagsBefore selector = takeWhile (~/= (T.unpack selector))
+
+getTagsAfter :: Text -> [Tag Text] -> [Tag Text]
+getTagsAfter selector = drop 1 . dropWhile (~/= (T.unpack selector))
+
+getTagsBetween :: Text -> Text -> [Tag Text] -> [Tag Text]
+getTagsBetween begin end = getTagsBefore end . getTagsAfter begin
+
+getTagAttributes :: Text -> Text -> [Tag Text] -> [Text]
+getTagAttributes selector attribute =
+  catMaybes
+  . fmap (maybeTagAttribute attribute)
+  . filter (~== (T.unpack selector))
+
+getTagAttribute :: Text -> Text -> [Tag Text] -> Maybe Text
+getTagAttribute selector attribute =
+  listToMaybe
+  . getTagAttributes selector attribute
+
+getTagTextAfter :: Text -> [Tag Text] -> Maybe Text
+getTagTextAfter selector tags =
+  case findIndex (~== (T.unpack selector)) tags of
+    Just index -> fmap T.strip $ safeGetAt (index + 1) tags >>= maybeTagText
+    Nothing    -> Nothing
+
+maybeTagAttribute :: Text -> Tag Text -> Maybe Text
+maybeTagAttribute name (TagOpen _ xs) =
+  fmap snd . find (\(x, _) -> x == name) $ xs
+maybeTagAttribute _ _ = Nothing
+
+safeGetAt :: Int -> [a] -> Maybe a
+safeGetAt index = listToMaybe . drop index