Adam Smyczek <[EMAIL PROTECTED]> wrote:
> data SampleType = A | B Int | C String | D -- .... etc.
deriving (Eq)
> sampleTypes = [A, B 5, C "test"] :: [SampleType]
>
If you derive from Eq, you can do
isA = (==) A
filter isA sampleTypes
or ad-hoc:
filter ((==) A) sampleTypes
things like
filter (\x -> case x of
{ A -> True
; B b | b > 2 -> True
; C c | c == "foo" -> True
; _ -> False}) sampleTypes
work, too. Admittedly, I'm lambda-spoilt.
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