[Haskell-beginners] Help in pattern matching

Jonas Almström Duregård jonas.duregard at gmail.com
Mon Mar 8 05:06:07 EST 2010


Maybe you want to use this type instead?

type TestData = (Either String Int, Either String Int)

There is also the function either which can save you some pattern matching.

There are some errors in your code. What is the type of test?

On 8 March 2010 10:11, Joe Fox <fox.joe87 at gmail.com> wrote:
> Hi Guys ,
>
>
> I am having a problem with patter matching .  I have declared following data
> type
>
> data TestData = DataConst1 Int String
>                         | DataConst2 Int Int
>                         | DataConst3 Sting String
>                         | DataConst4 String Int
>
>
> and now i have function "test" which behaves similarly for (DataConst1 and
> DataConst2 ) and behaves similarly from DataConst3 and DataConst4.
>
> for ex
>
> test (DataConst1 x y) = x
> test (DataConst2 x y )= x
>
> test (DataConst3 x y) = y
> test(DataConst4 x y )= y
>
>
> no my problem here is , is there any way i can merge these 4 statements in
> two statements .... some way i can match DataConst1 and DataConst2 in the
> same line it would save me a lot of rewriting of code
>
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