Data.TypedEncoding.Conv.Text.Encoding

Since: 0.2.2.0

Documentation

>>> :set -XScopedTypeVariables -XOverloadedStrings -XDataKinds -XFlexibleContexts -XTypeApplications
>>> import Test.QuickCheck
>>> import Test.QuickCheck.Instances.Text()
>>> import Test.QuickCheck.Instances.ByteString()
>>> import qualified Data.ByteString.Char8 as B8
>>> import Data.Char
>>> import Data.Either
>>> import Data.TypedEncoding
>>> import Data.TypedEncoding.Conv.Text
>>> let emptyUTF8B = unsafeSetPayload () "" :: Enc '["r-UTF8"] () B.ByteString
>>> :{
instance Arbitrary (Enc '["r-UTF8"] () B.ByteString) where 
     arbitrary =  fmap (fromRight emptyUTF8B) 
                  . flip suchThat isRight 
                  . fmap (encodeFAll @'["r-UTF8"] @(Either EncodeEx) @(). toEncoding ()) $ arbitrary 
instance Arbitrary (Enc '["r-UTF8"] () T.Text) where 
     arbitrary =  fmap (unsafeSetPayload ()) 
                        arbitrary 
instance Arbitrary (Enc '["r-ASCII"] () B.ByteString) where 
     arbitrary =  fmap (unsafeSetPayload ()) 
                  . flip suchThat (B8.all isAscii) 
                       $ arbitrary 
instance Arbitrary (Enc '["r-ASCII"] () T.Text) where 
     arbitrary =  fmap (unsafeSetPayload ()) 
                  . flip suchThat (T.all isAscii) 
                       $ arbitrary 
:}

decodeUtf8 :: forall xs c t. (LLast xs ~ t, IsSuperset "r-UTF8" t ~ True) => Enc xs c ByteString -> Enc xs c Text

With given constraints decodeUtf8 and encodeUtf8 can be used on subsets of "r-UTF8"

>>> displ . decodeUtf8 $ (unsafeSetPayload () "Hello" :: Enc '["r-ASCII"] () B.ByteString)
"Enc '[r-ASCII] () (Text Hello)"

"r-UTF8" is redundant:

>>> displ . utf8Demote . decodeUtf8 $ (unsafeSetPayload () "Hello" :: Enc '["r-UTF8"] () B.ByteString)
"Enc '[] () (Text Hello)"

decodeUtf8 and encodeUtf8 form isomorphism

\x -> getPayload x == (getPayload . encodeUtf8 . decodeUtf8 @ '["r-UTF8"] @() $ x)

\x -> getPayload x == (getPayload . decodeUtf8 . encodeUtf8 @ '["r-UTF8"] @() $ x)

These nicely work as iso's for "r-ASCII" subset

\x -> getPayload x == (getPayload . encodeUtf8 . decodeUtf8 @ '["r-ASCII"] @() $ x)

\x -> getPayload x == (getPayload . decodeUtf8 . encodeUtf8 @ '["r-ASCII"] @() $ x)

encodeUtf8 :: forall xs c t. (LLast xs ~ t, IsSuperset "r-UTF8" t ~ True) => Enc xs c Text -> Enc xs c ByteString

>>> displ $ encodeUtf8 $ utf8Promote $ toEncoding () ("text" :: T.Text)
"Enc '[r-UTF8] () (ByteString text)"