[ponzao]

`sum` does not accept a function as a parameter, the original example had an `foreach` instead of `sum`.

    list filter isEven foreach println

As a side note omitting that many commas and parenthesis is very rare at least based on the Scala projects I've worked on. The above example is equal to the one below:

    list.filter(isEven).foreach(println)

[virtualwhys]

Good points, I tend to mix it up, rarely going parens-free style, but also not parens by default either.

If you wanted to be really explicit you could do:

    list.filter(x=> isEven(x)).foreach(x=> println(x))

yuck ;-)

[ponzao]

That example is not quite equivalent, because now you are not passing `isEven` or `println` as arguments, you are passing anonymous functions that call `isEven` and `println`.