Two simple combinators on Element: getAttr and hasAttr.

src/Text/Taggy/Combinators.hs

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+module Text.Taggy.Combinators (hasAttr, getAttr) where
+
+import Prelude hiding (lookup)
+import Text.Taggy.DOM (Element(..), AttrName, AttrValue)
+import Data.HashMap.Strict (lookup, keys)
+
+hasAttr :: Element -> AttrName -> Bool
+hasAttr = flip elem . keys . eltAttrs
+
+getAttr :: Element -> AttrName -> Maybe AttrValue
+getAttr = flip lookup . eltAttrs

tests/Text/Taggy/CombinatorsSpec.hs

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+{-# LANGUAGE OverloadedStrings #-}
+
+module Text.Taggy.CombinatorsSpec where
+
+import Text.Taggy.Combinators
+import Test.Hspec
+import Text.Taggy.DOM
+import Data.HashMap.Strict
+
+spec :: Spec
+spec = do
+  let element = Element "html" (fromList [("xmlns", "http://www.w3.org/1999/xhtml")]) []
+  describe "hasAttr" $ do
+    it "Tests whether an attribute is present." $ do
+      (element `hasAttr` "xmlns") `shouldBe` True
+      (element `hasAttr` "href") `shouldBe` False
+  describe "getAttr" $ do
+    it "Retrieves present attributes." $
+      (element `getAttr` "xmlns") `shouldBe` Just "http://www.w3.org/1999/xhtml"
+    it "Nothing's missing attributes." $ 
+      (element `getAttr` "style") `shouldBe` Nothing