[Haskell-beginners] invalid type signature last2::: [a] -> a

[May Khaw]

The first one means that you gave a type signature for a function you did
not define.

The second one means that there are 2 last2 type signature, but you can
only have one.

What you want is something like :
last2 :: [a] - > a
last2 list = (put your function here)

On Sun, 9 Nov 2014 21:02 Roelof Wobben <r.wobben at home.nl> wrote:

>  Thanks,
>
> I changed it to this :
>
> last2::[a]-> a
> last2::last[a]
>
> but now I see these error messages:
>
>  src/Main.hs at 1:1-1:6 The type signature forlast2 lacks an accompanying
> binding
>  src/Main.hs at 2:1-2:6 Duplicate type signatures for last2
> at
> /home/app/isolation-runner-work/projects/75679/session.207/src/src/Main.hs:1:1-5
>
>
> /home/app/isolation-runner-work/projects/75679/session.207/src/src/Main.hs:2:1-5
> src/Main.hs at 2:1-2:6
>  The type signature for last2 lacks an accompanying binding
>
>
>
> akash g schreef op 9-11-2014 10:48:
>
> The naming convention for variables and functions is that they should
> start with a lower case letter.  Types have capitalized names.
>
>
> On Sun, Nov 9, 2014 at 3:12 PM, Roelof Wobben <r.wobben at home.nl> wrote:
>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> Hello,
>>
>> I try to solve the 99 haskell problems on several ways.
>>
>> But my first try which looks like this :
>>
>> Last2::[a]-> a
>> Last2:: last[list]
>>
>> gives the following error message :
>>
>> src/Main.hs at 1:1-1:6
>> Invalid type signature: Last2 :: [a] -> a Should be of form <variable>
>> :: <type>
>>
>> What am trying to do is say the input is a list which can be of integers
>> or chars so everything is the output can then also be of type everything.
>>
>> Roelof
>>
>>
>>
>>
>>
>>
>>
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>>
>
>
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