Is there an out of the box way to take from an Iterable until a predicate is satisfied, including th...

# announcements

[Rob Elliot]

Is there an out of the box way to take from an Iterable until a predicate is satisfied, including the element that first satisfies the predicate?

Something like:

val xs = listOf("a", "e", "c", "b", "d")
xs.takeUntil { it == "c" } == listOf("a", "e", "c")

[Shawn]

is takeWhile {} not what you’re looking for?

[Shawn]

or I guess, you’re looking for the inverse of takeWhile

[Rob Elliot]

No, takeWhile isn’t inclusive

[Rob Elliot]

Looks like not judging by this:
https://jivimberg.io/blog/2018/06/02/implementing-takewhileinclusive-in-kotlin/

[nanodeath]

I thought I might be able to come up with a one-liner for a list, but I think I hate it

val list = listOf("foo")
list.take(list.indexOfFirst { it == "bar" }.takeIf { it >= 0 }?.let { it + 1 } ?: list.size)

[ephemient]

honestly I'd like this solution the best, don't know why nothing like it is listed...

buildList {
    for (elem in list) {
        add(elem)
        if (predicate(elem)) break
    }
}

works with sequence too

[Nir]

Well, for a sequence you'd want to return another sequence, not a list

[ephemient]

well yes, and you'd use emit instead of add, but either way you don't need to keep a Boolean var