Predicates for checking if one or all elements of a collection satisfy a condition

[laszloesl]

Hey,

I wonder if you are planning on adding a way to describe exists (or any) and all first order predicates to extend the logical operators.

Something like:

iex> Predicator.evaluate!("ANY x in results: x.age >= 25", %{"results" => [%{"score" => 92, "age" => 25}, %{"score" => 10, "age" => 1}]})
{:ok, true}

iex> Predicator.evaluate!("ALL x in results: x.age >= 25", %{"results" => [%{"score" => 92, "age" => 25}, %{"score" => 10, "age" => 1}]})
{:ok, false}

This would be a useful extension. I'm happy to try to give it a shot and create a PR if you think this makes sense.