Hello Tom,
Thursday, May 4, 2006, 5:20:54 PM, you wrote:
> I was experimenting with records this morning and discovered a slight
> oddity...
> data Rec = RecA { a :: Int } | RecB { a :: Int, b :: Bool } deriving Show
> main :: IO ()
> main = do
> print (b (RecB { a = 1, b = True })) -- Works
> print (b (RecA { a = 1 })) -- Doesn't
> Of course extracting "b" from a record constructed with "RecA" is
> illegal, but the compiler did not warn against it (ghc -W). I was
> expecting a warning similar to non-exhaustive pattern matching.
> Are records with optional fields really type safe?
it shpuld be a runtime check. seems that Haskell is so changed your
mind that you expect that compiler should check anything at compile time
:)
--
Best regards,
Bulat mailto:[EMAIL PROTECTED]
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