Being a little bit frustrated over the error messages some prelude functions (like !!) give, I tried to write a different version.

```
--(!!!) :: (Show a,Integral b)=> [a]->b->a
as !!! y=f as y
where f (x:xs) b= if b==0
then x
else f xs (b-1)
f [] _= error "!!!: list "++(show as)++" has less than "++show y++" elements"
```

However the function type is

```
*Handydandy> :type (!!!)
(!!!) :: (Show a, Num a, Eq a) => [[Char]] -> a -> [Char]
```

I do not understand why the first argument is inferred to be a list of Strings here instead of just a list of show instances. Could anybody explain?

Answer:

You need some parenthesis (or a `$`

) in the last line:

```
error ("!!!: list "++(show as)++" has less than "++show y++" elements")
```

Right now its being parsed as

```
(error "!!!: list ") ++ (show as) ++ " has less than " ++ show y ++" elements"
```

which makes Haskell think that `(!!!)`

is returning a string, which then would mean that its input must be a list of strings.

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