I see I got it wrong... It's the other way around in read x :: Int, it's Int which has an instance of Read... http://www.haskell.org/ghc/docs/latest/html/libraries/base/Prelude.html#v:re... So if Data.Text has an instance of Read I can convert a String to Data.Text using Read... Not what I wanted. Must I really do Data.Text->String->Int or is there a direct way? emmanuel On 14.12.2012 15:57, Emmanuel Touzery wrote:
Hello,
I expected "read" to work directly on a Data.Text because Data.Text has an instance of the Read class, but it seems to fail:
--------- import Data.Text
main = do let a = pack "1" let b = read a :: Int putStrLn "parsed OK" ---------
test.hs:5:22: Couldn't match expected type `String' with actual type `Text' In the first argument of `read', namely `a' In the expression: read a :: Int In an equation for `b': b = read a :: Int
Sure I can do"read (unpack a) :: Int" but there must be a way to do it directly?
Emmanuel