Scala compiler error: "identifier expected but integer literal found". Why?

Question

The code is obvious, and I fail to see what's wrong with it. ``` object TestX extends App { val l= List[String]( "a","b","c" ) val n= l.size def f( i:Int )= l[(i+1)%n ] } ``` Compiler output (Scala 2.9.2): ``` fsc -deprecation -d bin src/xxx.scala src/xxx.scala:11: error: identifier expected but integer literal found. def f( i:Int )= l[(i+1)%n] ^ ```

Accepted Answer

Brackets `[`, `]` in Scala are used to declare or apply type parameters. Getting an element in a sequence or array is the `apply(index: Int)` method where `apply` may be omitted. Thus:

```
def f(i:Int) = l.apply((i + 1) % n)
```

or short

```
def f(i:Int) = l((i + 1) % n)
```

Note that `apply` and `size` on a `List` take time O(N), so if you need those operations often for large lists, consider using `Vector` instead.

Scala compiler error: "identifier expected but integer literal found". Why?

Solution

Problem