8d2bb39 · typeable/dom-parser

git.iko.soy/typeable/dom-parser

Attribute parsing class

commit8d2bb395227fd2f4a58c5ac6adca967b8eff78bc authorVladislav Zavialov <vlad.z.4096@gmail.com> dateThu 22 Dec 2016, 16:56 (10 years ago) parent4ee841f

2 files changed+61−19

compare with master

unifiedsplit

src/Text/XML/DOM/Parser/Class.hs+39−14 src/Text/XML/DOM/Parser/Combinators.hs+22−5

src/Text/XML/DOM/Parser/Class.hs+39−14

@@ -18,22 +18,23 @@ module Text.XML.DOM.Parser.Class

1818 , unitFromDom

1919 , voidFromDom

2020 , scientificFromDom

21+ -- * FromAttribute

22+ , FromAttribute(..)

2123 ) where

2224

23−import Control.Applicative

24−import Control.Lens

25−import Data.Fixed

26−import Data.Monoid

27−import Data.OpenUnion

28−import Data.Scientific

29−import Data.Text (Text)

30−import qualified Data.Text as T

31−import Data.Typeable

32−import Data.Void

33−import Text.XML

34−import Text.XML.DOM.Parser.Combinators

35−import Text.XML.DOM.Parser.Types

36−import TypeFun.Data.List hiding (Union)

25+import Control.Applicative

26+import Control.Lens

27+import Data.Fixed

28+import Data.Monoid

29+import Data.OpenUnion

30+import Data.Scientific

31+import Data.Text as T hiding (empty)

32+import Data.Typeable

33+import Data.Void

34+import Text.XML

35+import Text.XML.DOM.Parser.Combinators

36+import Text.XML.DOM.Parser.Types

37+import TypeFun.Data.List hiding (Union)

3738

3839proxyFromDom

3940 :: forall proxy m a

@@ -162,3 +163,27 @@ unitFromDom = pure ()

162163-- | Never parses successfully. It is just 'mzero'

163164voidFromDom :: (Monad m) => DomParserT Identity m Void

164165voidFromDom = empty

166+

167+class FromAttribute a where

168+ fromAttribute :: Text -> Either Text a

169+

170+instance FromAttribute () where

171+ fromAttribute _ = Right ()

172+

173+instance FromAttribute Text where

174+ fromAttribute = Right

175+

176+instance FromAttribute Char where

177+ fromAttribute = readChar

178+

179+instance FromAttribute Int where

180+ fromAttribute = readContent

181+

182+instance FromAttribute Integer where

183+ fromAttribute = readContent

184+

185+instance (Typeable a, HasResolution a) => FromAttribute (Fixed a) where

186+ fromAttribute = readContent

187+

188+instance FromAttribute Scientific where

189+ fromAttribute = readContent

src/Text/XML/DOM/Parser/Combinators.hs+22−5

@@ -28,6 +28,7 @@ module Text.XML.DOM.Parser.Combinators

2828 , maybeReadContent

2929 -- * Parsing attributes

3030 , parseAttribute

31+ , parseAttributeMaybe

3132 ) where

3233

3334import Control.Lens

@@ -309,8 +310,24 @@ parseAttribute

309310 -> (Text -> Either Text a)

310311 -- ^ Attribute content parser

311312 -> DomParserT Identity m a

312−parseAttribute attrName parser = getCurrentAttribute attrName >>= \case

313− Nothing -> throwParserError $ PEAttributeNotFound attrName

314− Just aval -> case parser aval of

315− Left err -> throwParserError $ PEAttributeWrongFormat attrName err

316− Right a -> return a

313+parseAttribute attrName parser =

314+ parseAttributeMaybe attrName parser >>= \case

315+ Nothing -> throwParserError $ PEAttributeNotFound attrName

316+ Just a -> return a

317+

318+-- | Parses attribute with given name.

319+--

320+-- @since 1.0.0

321+parseAttributeMaybe

322+ :: (Monad m)

323+ => Text

324+ -- ^ Attribute name

325+ -> (Text -> Either Text a)

326+ -- ^ Attribute content parser

327+ -> DomParserT Identity m (Maybe a)

328+parseAttributeMaybe attrName parser =

329+ getCurrentAttribute attrName >>= \case

330+ Nothing -> return Nothing

331+ Just aval -> case parser aval of

332+ Left err -> throwParserError $ PEAttributeWrongFormat attrName err

333+ Right a -> return $ Just a