[Haskell-cafe] parser error in pattern

[Ivan Lazar Miljenovic]

On 18 October 2011 08:56, kolli kolli <nammukolli04 at gmail.com> wrote:
> after parsing a string i am evaluating it...
> string if t1 then t2 else t3
> my code is
> eval1 :: Term ->  Maybe Term
> eval1(If Tru t2 t3) = Just t2
> eval1(If Fls t2 t3) = Just t3
> eval1(If t1 t2 t3) =  case eval t1
>                     where eval1(If t1 t2 t3) =  Just t1
>
> eval :: Term -> Term
> eval (IsZero Zero) = Tru
> eval (Zero) = Zero
> eval(Pred Zero) = Pred Zero

Your case statement is incomplete for starters...

Can you please provide the actual error message as well?  Your
definition of Term would also be useful.

>
> On Mon, Oct 17, 2011 at 3:46 PM, Ivan Lazar Miljenovic
> <ivan.miljenovic at gmail.com> wrote:
>>
>> On 18 October 2011 08:43, kolli kolli <nammukolli04 at gmail.com> wrote:
>> > hey can anyone tell me what is parser error in parser??Plz help me out
>>
>> It's when the parser can't parse what it's provided.... providing the
>> code that caused the problem and the actual error message is required
>> for a more detailed explanation.
>>
>> --
>> Ivan Lazar Miljenovic
>> Ivan.Miljenovic at gmail.com
>> IvanMiljenovic.wordpress.com
>
>



-- 
Ivan Lazar Miljenovic
Ivan.Miljenovic at gmail.com
IvanMiljenovic.wordpress.com