Scala Optional doubt filter method

Question

I was reading through the Scala docs, and looking through the Option

class I saw an implementation filter

that looks like this:

final def filter(p: A => Boolean): Option[A] = 
  if (isEmpty || p(this.get)) this else None

Why do we need to check if our instance is empty Option

? Wouldn't that lead to None

anyway?

+3

goral 03 Sep '14 at 9:26

1 answer

Travis brown · Accepted Answer · 2014-09-03T09:39:28+0000

||

is short-circuited, so checking isEmpty

first ensures that get

it will not be called on an empty option (to throw an exception).