How to filter a collection using a list of predicates

Issue

I have a list of elements, for example:

val myList = listOf(1,2,3,4,5,6,7)

The list could be of any type, this is just an example. Now I have a list of predicates of arbitrary length:

val myPredicates = listOf({myInt: Int -> myInt > 1}, {myInt: Int -> myInt%2 == 0})

How do I filter the list by applying all the predicates, in order of the list, to myList and get the result in a new list? I feel like the answer lies somewhere in using the reduce or fold operator, but the answer is eluding me.

Solution

The simplest solution I can think of is using all on the predicates list in your filter call like this:

myList.filter { elt -> myPredicates.all { it(elt) } }

The part myPredicates.all { it(elt) } returns true when all predicates are true for the given element elt.

Answered By - Joffrey