hi,

data StringOrInt = TisanInt Int | TisAString String

instance Eq (StringOrInt) where 
(==) (TisanInt v) (TisanInt v') = v == v'
(==) (TisAString s) (TisAString s') = s == s'


prelude>

Instance_testen.hs:4:37: error:
    Ambiguous occurrence ‘==’
    It could refer to either ‘Prelude.==’,
                             imported from ‘Prelude’ at Instance_testen.hs:1:1
                             (and originally defined in ‘GHC.Classes’)
                          or ‘Main.==’, defined at Instance_testen.hs:4:1
  |
4 | (==) (TisanInt v) (TisanInt v') = v == v'   |                                     ^^

Instance_testen.hs:5:41: error:
    Ambiguous occurrence ‘==’
    It could refer to either ‘Prelude.==’,
                             imported from ‘Prelude’ at Instance_testen.hs:1:1
                             (and originally defined in ‘GHC.Classes’)
                          or ‘Main.==’, defined at Instance_testen.hs:4:1
  |
5 | (==) (TisAString s) (TisAString s') = s == s' 
  |                                         ^^
[1 of 1] Compiling Main             ( Instance_testen.hs, interpreted )
Failed, no modules loaded.



what gives?