If you just need to go back and forth from String to Text, why do you need to be generic? pack and unpack from Data.Text do the job.
Plus, in the way of what Christopher said, you can use the OverloadedStrings extension. You can then use the string syntax at a place that expects a text:
{-# LANGUAGE OverloadedStrings #-}
import Data.Text
t :: Text
t = "Hello"
Any instance of the IsString class can be used in this way, not only Text.
2012/3/8 Simon Hengel
<sol@typeful.net>
Hi!
When writing library code that should work with both String and Text I
find my self repeatedly introducing classes like:
class ToString a where
toString :: a -> String
class ToText a where
toText :: a -> Text
(I use this with newtype wrapped value types backed by Text or
ByteString.)
So I wonder whether it would be a good idea to have a package that
provides those classes.
Or maybe just ToText, and provide default implementations of toString
and toText, like:
class ToText a where
toText :: a -> Text
toText = Text.pack . toString
toString :: a -> String
toString = Text.unpack . toText
How do you guys deal with that? Any thoughts?
Cheers,
Simon
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